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2006 10 31 BOAa BOARD OF APPEALS AGENDA La Quinta Civic Center Study Session Room 78-495 Calle Tampico La Quinta, CA 92253 Tuesday, October 31, 2006 2:00 P.M. CALL TO ORDER A. Pledge of Allegiance B. Roll Call 11. CONFIRMATION OF AGENDA Corrections, deletions or reorganization of the agenda III. PUBLIC COMMENT The Board of Appeals reserves the right to limit discussion on any topic to five minutes or less. IV. CONSENT CALENDAR A. Approval of Minutes - None B. Department Report - None V. PUBLIC HEARING A. None VI. BUSINESS ITEMS A. Election of Chairperson B. Appeal of the Decision of the City Manager concerning La Quinta Staff discretionary policies regarding the suitability of alternate materials and methods of installation for an underground retention facility as applied to the Washington Park development Board of Appeals Agenda October 31, 2006 VII. CORRESPONDENCE AND WRITTEN MATERIAL A. None Vlll. COMMISSIONER ITEMS A. None IX. ADJOURNMENT a: appeal I1\06 2 0j_ -� 4 `y OFT BOARD OF APPEALS MEETING DATE: October 31, 2006 ITEM TITLE: Appeal of the Decision of the City Manager Concerning La Quinta Staff Discretionary Policies Regarding the Suitability of Alternate Materials and Methods of Installation for an Underground Retention Facility as Applied to the Washington Park Development RECOMMENDATION: Hear the presentations and review the materials provided by the appellant and City staff and decide whether to uphold, modify or overturn the decision of the City Manager. FISCAL IMPLICATIONS: The developer estimates that a concrete retention system will cost approximately $204,350 more than the zinc coated steel system that is being proposed. BACKGROUND: On August 25, 2006, the City Manager sent a letter to Mr. Jack Tarr denying the use of a metal structure for an underground retention system and sustaining the requirement for a maximum of a 36 hour retention time. That letter is included as Attachment 1. On September 8, 2006, Mr. Tarr appealed the City Manager's decisions in a letter which is included as Attachment 2. Included as Attachment 3 is material provided by the appellant in support of his position regarding these issues. Included as Attachment 4 are materials provided by the City's Public Works and Engineering Department in support of its position not to allow metal as a component in an underground retention system. It should be noted that the Building and Safety Department also sent the material provided by the appellant to a structural engineer (Jeffrey Bronz Young) for review and comment. That review concluded that in theory a steel retention system could be designed to resist the applicable loads that it would be subjected to on day one of its installation; however, Mr. Young did not feel it was in his area of expertise to comment on the durability of the steel and its ability to adequately resist the applicable loads over a period of time in the proposed application. Mr. Young referred the department to Mr. Craig Hill as a possible resource for review of the materials. Mr. Hill was contacted by the Building and Safety Department and hired to review the material provided by the appellant and to make recommendations as to the suitability of multi -plate zinc coated structural steel as a component in an underground retention system. Included as Attachment 5 is a report from Mr. Craig S. Hill of Earth Systems Southwest discussing certain areas of concern. One of those concerns which is key to the City's position not to allow the steel plate to be used is the fact that there is no mechanism in place to guarantee that the system will be inspected, maintained and ultimately replaced or removed prior to its failure. Publicly owned facilities, such as those under Caltrans jurisdiction, have inspection programs, maintenance schedules and a budget to insure their continued viability. There is nothing in place that will prohibit the proposed system from becoming "out of sight out of mind" until there is a failure, regardless if it is five years from now or 150 years from now. Due to the fact that the system is located under area subject to vehicular traffic, such a failure could result in injury or even death. The City's requirement for the system to drain within 36 hours is an effort to insure that standing water is not available for mosquitoes to breed. This obviously is an important issue in light of the West Nile Virus. Staff contacted several agencies, including Coachella Valley Mosquito and Vector Control, in an attempt to determine the gestation period for mosquitoes capable of carrying the Virus and discovered that eggs could hatch within 48 to 72 hours. Based on that information, one could argue that the maximum time allowed for water to percolate into the soil should be 48 or 72 hours. However, no one will argue that the open bottom of the proposed system will continue to function as effectively years from now as it will on its first day of operation without periodic maintenance. Debris, oil from the parking lot etc. will build up over time and negatively affect the percolation rate of the system. Without a guaranteed maintenance program in place, one must conservatively conclude that none will occur. By requiring a 36 hour maximum for the standing water, the system could be functioning at one half its design parameters without presenting a public health concern. Representatives for the appellant, the City's Public Works and Engineering Department and Mr. Craig Hill will be present at the hearing to answer any questions the Board may have. FINDINGS AND ALTERNATIVES: Alternatives available to the Appeals Board include: Uphold the decision of the City Manager not to allow multi -plate zinc coated steel as a component of an underground retention system and to require a 36 hour maximum retention time; or 2. Modify the decision of the City Manager; or 3. Overturn the decision of the City Manager. Respectfully submitted, Tom Hartung Secretary to the Board of Appeals ATTACHMENT 1 P.O. Box 1504 LA QUINTA, CALIFORNIA 92247-1504 78-495 GALLF TAMPICO LA QUINTA, CALIFORNIA 92253 August 25, 2006 Mr. Jack Tarr Washington 111, LTD. 1-0240 Rancho Viejo Road, Suite B San Juan Capistrano, CA 92675 Re-. Underground Retention for Washington Park Dear Mr. Tarr: r (760)777-7000 ]FAX (760) 777-7101 AUG 19 2606 The meeting that you requested about underground retention was held at the City on Thursday, August 3, 2006. It was acknowledged by everyone at the meeting that the intended application for the underground storage was beneath a parking lot for a commercial development. It was also acknowledged that failure of the structure could result in the collapse of the parking lot. This structural collapse could affect adjacent buildings, cause economic loss to both tenants and the City, and/or cause citizen injury. In this event, the entire retention facility and parking lot would have to be reconstructed. It was also acknowledged by everyone at the meeting that a concrete underground structure would have a longer service life than a metal underground structure under identical conditions. It is a common practice in engineering to evaluate alternative materials, especially if there are cost differences. A cost analysis provided by your consultant, Steve Speer, shows that a concrete structure would cost about $462, 000 while the equivalent metal structure would cost only $257,650. The difference in cost is $204,350. Given this particular application (underground retention below a parking lot), and the potential adverse ramifications to the health, safety and welfare of citizens due to failure of the system, the Public Works department believes that it is in everyone's best interest to use the concrete system for this project. Nothing that was presented at your meeting of August 3, leads me to believe that this conclusion is not correct. G:\Genovese, T\letters\Tarr, Jack re Underground Retention 08-25-2006.doc N♦ ' At the meeting, you asked for background information on how the City arrived at the 36 hour max retention time standard for underground retention as promulgated in the draft policy. Due to our limited experience with underground retention, my staff attempted to advance a reasonable standard that is accepted in other jurisdictions. The 36 hour max retention time standard is required by many local Arizona jurisdictions including Phoenix, Scottsdale, Tempe and Tucson. Additionally, the 36 hour max retention time standard is required by the Maficopa County Health Department (pest control requirement). Lastly, you expressed concern that Coachella Valley Water District staff may not be prepared to grant approval on deep dry wells. My staff has liaised with CVWD staff on this issue and is confident that CVWD will not delay approval of Maxwell or equivalent systems. These systems have already been approved by CVWD and have been physically installed on several projects in La Quinta. If you have any questions regarding this matter, please feel free to contact Tim Jonasson, Public Works Director/City Engineer, at (760) 770-7042 or Ed Wimmer, Principal Engineer, at (760) 777-7088. Sincerely, Thomas P. Genovese City Manager TRJ/EJW/cd c: Tim Jonasson, Public Works Director/City Engineer Ed Wimmer, Principal Engineer Paul Goble, Senior Engineer File G:\Genovese, T\letters\Tarr, Jack re Underground Retention 08-25-2006.doc 80618 DECLARATION AVE. INDIO, CA 92201 WASHINGTON III, LTD September 8, 2006 0 ATTACHMENT 2 '4 PUBLIC WORKS 760-775-7967 Phone 760-775-8329 Fax RELE11 M . Mr. Tim Jonasson 2006 Public Works Director/City Engineer SEP 1 Mr. Tom Hartung Director of Building & Safety Ms. June S. Greek City Clerk City of La Quinta 78A95 Calle Tampico La Quinta, California 92253 RE: Appeal of Decision of Director of Public Works (on Behalf of the Building and Safety Department) and Appeal of the Decision of the City Manager Concerning La Quinta Staff Discretionary Policies Regarding Suitability of Alternate Materials and Methods of Installation for Underground Retention Facility as applied to the Washington Park Development To Whom It May Concern: Washington 111, Ltd has been attempting to resolve the La Quinta requirements for a passive `open bottom' on -site private underground retention chamber for receipt of on -site storm water for a number of months so they can proceed with the completion of their precise grading plans and obtain a permit accordingly. Instead, they have received conflicting, unsupported and inappropriate interpretations of policy which has not been reviewed or approved by the City Council. While this appeal is for the project, Washington Park, it focuses on issues of concern to the entire commercial development community within the City. Mr. Tarr sets forth all of the following grounds for appeal. L The pronosed 5 eauge multi -plate zinc coated structural steel passive retention facility is structurally sound and not subject to collapse Washington 111, Ltd has submitted information regarding the multi -plate five gauge zinc coated structural steel open bottom passive retention chamber which they City of La Quinta Re: Appeal of Rejection of Retention Alternative September 8, 2006 Page 2 proposed to use, but was told by the City — without any factual support — that it was subject to "collapse" and that, therefore, a concrete structure had to be used. City staff repeatedly failed to consider the engineering submittals from Contech, Inc. and Parsons Engineering regarding underground steel structures. 2. The requirement for a drywell system to obtain.a 36 hour maximum retention time is unnecessary and inappropriate given local vector control suggested parameters. Washington 111, Ltd also raised concerns regarding the discretionary requirement for a 36 hour maximum retention time and a drywell system. The Director's requirement of a drywell system to achieve a 36 hour maximum retention time is purportedly based on a 36 hour time period imposed by cities in Arizona and purportedly required by Maric:opa County Health Department for vector control. There is no scientific basis suggesting that the 36 hour time period imposed by Arizona cities is necessary for vector control or other health reasons in the City of La Quinta. Please also note that the cities in Arizona have no prohibition against use of alternate materials for retention chambers including zinc coated multi -plate structural steel. 3. Draft Underground Retention Basin Design Requirements dated June 29 200-5 The Engineering Standards utilized by the Public Works staff to condition underground retention basins in commercial centers are an abuse of administrative discretion and are without support on engineering or health and safety grounds. Specifically, Washington 111, Ltd challenges Engineering Standards as set out in the June 29, 2006, Draft Underground Retention Basin Design Requirements (which, although "draft" have been applied for over .a year) as well as the discretionary administrative interpretations of such policies, including #97-03. The Director's rejection of the zinc coated structural steel system and requirement for the drywell system are based solely on adherence to particular building and construction standards set forth in a new draft Engineering Bulletin posted on June 29, 2006. We would respectfully submit that those particular building and construction standards should have been submitted for City Council and public review as an ordinance amending Title 8 of the City's Municipal Code. The particular standards and the Director's strict adherence to them are apparently intended solely to counter Washington 111, Ltd's alternative proposal and are without scientific support. _ The Director's strict adherence to particular draft Bulletin standards is even contrary to the standards themselves. For example, the Bulletin expressly allows use of an "approved equal" to reinforced concrete vault style systems. Please note there is no minimum design service life criteria established for achieving an "or equal" status. Also, the Bulletin does not expressly require drywell systems except as needed to address E City of La Quinta Re: Appeal of Rejection of Retention Alternative September 8, 2006 Page 3 standing, stagnant water and vector control systems. For perforated systems, the Bulletin also expressly states that drywell systems should be approached as an "at risk" design subject to Coachella Valley Water District approval. 4. City staff has failed and refused to consider objective engineering and related information provided to them to support the request for an alternative system. Contech, Inc. manufactures both the Department approved and installed concrete system (which does not adhere to a 36 hour draw down time standard) and the proposed steel system. During an August 3, 2006 meeting between the Director, City Manager and Washington 111, Ltd. representatives, a Contech representative verified that the proposed zinc coated structural steel system has a design service life equal to or greater than the Director approved concrete system. In addition, a structural engineer from Parson's Engineering did an independent study of metal systems and found that the systems were structurally sound. In addition, the proposed product exceeds the minimum required design service life criteria for the product category established by the Army Corp of Engineers, the United States Department of Transportation Federal Highway Administration and the California Department of Transportation (CalTrans). All of these agencies including the American Association of State and Highway Transportation Officials (AASHTO) allow the proposed product and encourage diversity in choice of materials for engineering solutions. The Director does not have internal or independent structural engineering analysis that contradicts the conclusions of Parsons and Contech. Instead, the Director bases his decision upon the unfounded fear that the system could collapse and cause damage to property and life because the system will be located beneath a parking lot. The Director presents no analysis that the risk of collapse is.significant for a steel structure or that the risk of collapse would be significantly lessened with a concrete structure. The Director presents no analysis of whether the significant additional cost for a concrete structure will provide any significant public safety benefits. After raising all of these issues, and repeatedly meeting with staff and the City Manager in an effort to resolve them, on August 29, 2006, Washington 111, Ltd's General Partner, Mr. Tarr received a letter from Thomas Genovese, City Manager, advising Mr. Tarr of a decision by Tim Jonasson, Director of Public Works, to reject Mr. Tarr's proposed use of alternate materials and methods of installation for an underground retention facility. The Director's decision was made on behalf of the City's Department of Building and Safety pursuant to Section 8.70.100(B) of the City's Municipal Code, Washington 111, Ltd. hereby appeals that decision pursuant to La Quinta Municipal Code Section 8.01.030(B). Mr. Genovese also rejected Washington I 11, Ltd.'s request (and mischaracterized the meeting regarding that request); because of that and the application City of La Quinta Re: Appeal of Rejection of Retention Alternative September 8, 2006 Page 4 of discretionary Engineering Standards and policies, we also appeal alternatively pursuant to La Quinta Municipal Code Section 2.04.100, For the foregoing reasons, Washington 11 1, Ltd. respectfully requests a hearing before the appropriate City body to consider the merits of this appeal. The amount o f the fee included here is the amount stated to us by the City Clerk's office. Thank you for your consideration of this matter. Sincerely, ,,-'Ja Tarr Cenral Partner 'Washington 111, Ltd Enclosure: $175 Filing Fee Cc: McCormick, Kidman & Behrens City Council LI ATTACHMENT a : 0 «`,to) 0 ? @ » © *, »/k■»:a> ►»w._#.< ; l « � . - L QUINTA APPEAL OAR# e <e w At'�- .¥«.�© TABLE OF CONTENTS EXECUTIVE SUMMARY SAMPLE PICTURES 1ST SUBMITTAL PACKET TO CITY 2nd SUBMITTAL PACKET TO CITY EXECUTIVE SUMMARY Introduction Galvanized metal retention basins and detention basins are used throughout the United States because of the need for new projects to comply with the Clean Water Act. The detention basin pictured on the cover was constructed in Laurel, Maryland in the early 1990's. It is significantly larger than the structure proposed for installation at the Washington 111 shopping center. The sample pictures in Section 2 of this report include a retention basin that was constructed in Los Oso, California (near Morro Bay) that is more exemplary of the size proposed for installation at the Washington 111 project site. The Washington 111 retention basin will be 25 feet wide x 12 feet tall x approximately 140 feet long, and constructed of 5 gauge galvanized structural steel (also known as bridge plate). The Washington 111 group initially proposed the galvanized structural steel arch retention basin earlier this year in June when it submitted Packet #1 to city engineering staff for review and approval (see Section 3 of this report). Engineering staff rejected the proposal because of past personal experience with thin gauge corrugated steel pipe. The 15t Submittal Packet was lightly regarded by city engineering staff in spite of the fact that it included: 1. a facility service life survey conducted by Parsons Brinkerhoff of galvanized metal detention basins in the Washington DC area, 2. information that thicker metal and a thicker zinc coating yields a longer service life --- specifically the 5 gauge structural steel plate arches yield a longer service life than the thin gauge structures studied by Parsons Brinkerhoff. 3. site specific soil data for the Washington 111 project site that can be applied to a chart that predicts the service life of the proposed structure. The Washington 111 group appealed the engineering department decision to the City Manager, hoping the information would be reviewed more thoroughly, but personal experience with thin gauge material in the engineering department carried the day and the City Manager issued his rejection letter (see Section 7 of this report). Subsequent to the City Manager's rejection, the Washington 111 group prepared a 2nd Submittal Packet that was submitted to the city engineering department on September 22, when the Building Industry Association (BIA) engineering group met with city staff regarding its draft engineering bulletins, one of which addresses proposed requirements Executive Summary Page 1 of 3 for underground retention basins. The draft bulletin proposes "concrete only under- ground retention basins, or approved equal". The 2nd Submittal Packet provided new information to further educate engineering staff in hope of obtaining their concurrence the proposed galvanized steel plate structure is a "functional" equal to a concrete structure. Engineering staff requested additional information at the September 22 meeting with the BIA group, and pursuant to that request, the 3`d Submittal Packet was provided to city engineering staff on October 2, 2006. The balance of this Executive Summary provides a synopsis of the three submittal packets as they are voluminous and highly technical, but the theme of each packet is easily understood. 1st Submittal Packet This packet contains a survey performed by Parsons Brinkerhoff, one of the leading engineering firms in the world, of galvanized detention basins installed in the Washington DC area. The survey validates the service life formulas/charts that are commonly used to predict the service life of galvanized metal structures. This packet also includes a service life calculation for the structure proposed at the Washington 111 site. The calculation is based on site specific soil data and predicts a service life of 289 years. 2nd Submittal Packet This packet contains information that demonstrates the use of galvanized metal structures to be in the mainstream of engineering practice. In other words, the Washington 111 proposal is not in the engineering fringe of rarely used concepts. To validate that thought, this packet reveals three large public agencies in the civil engineering field, perhaps the most respected public authorities in the civil engineering field: 1) US Army Corps of Engineers, 2) Federal Highway Administration, and 3) Caltrans all advocate the use of galvanized metal structures. All three agencies use the same service life chart(s) to predict the service life of a proposed structure. Their chart(s) are essentially the same as the chart submitted in the 1st Submittal Packet, except they apply a factor of safety of 2, which means these agencies would accept the estimated service life of the proposed structure to be 145 years instead of 289. When the Federal Highway Administration wanted to publish its guide document on the use of galvanized metal, it turned to the Army Corps to produce the document. In the course of producing that document, the Army Corps used Caltrans' service life chart. Executive Summary Page 2 of 3 3rd Submittal Packet This packet proposes that La Quinta use Caltrans' design practice for galvanized metal structures. There is an entire chapter (42 pages) in the Caltrans Highway Design Manual devoted to designing galvanized metal structures. The packet also addresses the notion that city engineering bias resulting from past bad experience with thin gauge galvanized steel pipe does not give 5 gauge galvanized structural steel plate structures a fair hearing. Conclusion The Washington 111 group believes the 5 gauge galvanized structural steel plate arch retention basin is a "functional" equal to the concrete only structures that engineering staff is currently approving. The 145-year service life is sufficiently long enough to challenge the longevity of concrete. Moreover, the proposed structure provides more head room for maintenance service than the concrete structures that are currently being approved. As a result, we respectfully request the Appeal Board to vote in favor of the proposed structure and allow La Quinta to enjoy the benefits that galvanized structural steel provides the rest of American society. Executive Summary Page 3 of 3 21 FourArches: 35'Wide x1TTall x4OO'Ljong Wag -Mart Parking Lot Russett Center(p 1-295 & Hwy198 Laurel, MID I SPEER Civil CONSULTING ENGINEERS ... hietpin9 you create /Se community asset you envision June 5, 2006 Timothy R. Jonasson, Public Work Director/City Engineer LA QUINTA PUBLIC WORKS DEPARTMENT 78-495 Calle Tampico La Quinta, CA 92253 Dear Mr. Jonasson: Underground Storm Water Retention Chamber — Galvanized Metal Plate Arch Washington Park, PM 30903 Pursuant to our phone conversation late last week regarding the subject underground storm water retention chamber, and its forecasted service life, please find enclosed herewith the supporting information that I stated would bring some science to this topic. The enclosed info is divided into two sections that I have entitled: 1) the Parson Brinkerhoff Study, and 2) Galvanized Metal Durability Info: 1) The "Parsons Brinkerhoff Study" file contains the results and information gleaned from a comprehensive study conducted by Parsons Brinkerhoff of galvanized corrugated metal storm water detention systems in the Washington DC area. Their study concludes: "the total service life of the structures would be in excess of 100 years" (pgs 6 & 8) b. The thickest, pipe metal, included in the study was 10 gauge (pg 5), Most were in the 12 to 16 gauge range, where the bigger the gauge number the thinner the metal. (Note: the metal plate structure proposed for Washington Park will be 5 gauge). c. PB found the AISI Method (based on the Caltrans Method) provides a more accurate/realistic service life prediction than the California Method (pgs 6 & 8). 50855 WASHINGTON ST ♦ SUITE C-280 ♦ LA QUINTA ♦ CALIFORNIA 92253 Office 760.285.7335 Fax 760. 269,3580 w .speercivil.net Timothy R. Jonasson June 5, 2006 Page 2 of 3 The service life of detention systems appears to be driven by soil -side corrosion (pg 8). PB made that statement because they found no significant water -side invert deterioration. It should be noted that the structure proposed for Washington Park will have an open bottom (ie no metallic invert) thus the findings of the PB study are extremely relevant to the Washington Park proposal. 2) The "Galvanized Metal Durability Info" is a compendium of three documents consisting of: 1) a service life calculation by Darwin Dizon with Contech, 2) selected pages from the Handbook of Steel Drainage & Highway Construction Products publish by American Iron and Steel Institute (AISI), and 3) the soils report for Washington Park. Relevant info in this file includes: a. Mr. Dizon estimates the service life of the proposed structure for Washington Park to be 289 years using the AISI Method (see calculation on pg 2). b. The AISI formula is typically used for estimating the service life of the structure invert where abrasive flows are a factor, but the Washington Park application has no invert. As a result, the formula "may be overly conservative for structural plate' applications (such as Washington Park) as stated on pg 7. PB's Washington DC study, which validated the AISI formula for estimating service life of detention systems where soil -side corrosion is the key factor, provides reassuring relevance to Mr. Dizon's use of the formula. C. By design, the zinc coating on the metal plate acts as a sacrificial anode in the corrosion process in lieu of corrosion attacking the structural steel. Hence, the service life of the structure is a function of how long the zinc coating provides cathodic protection. The primary factors in the soil contributing to rapid deterioration of the zinc coating are: low pH, low electrical resistivity, and high moisture content. The soil at Washington Park offers a favorable set of conditions for implementation of a galvanized metal plate structure, to wit: 1. "The predictive method.... depended on whether the pH exceeded 7.3." (pgs 6 & 7) The soil pH at Washington Park is 7.5 (pg 12) 2. The electrical resistivity for Washington Park is 1533 ohms and in mid -range to the soils encountered in the PB study. 3. The moisture content in the Washington Park soil is low in most locations, but does increased to as much as 29% in the deeper clay layers. 50855 WASHINGTON ST ♦ SUITE C-280 ♦ LA QUINTA ♦ CALIFORNIA 92253 Office: 760,285.7335 Fax: 760.269.3580 w .Speercivi).net Timothy R. Jonasson June 5, 2006 Page 3 of 3 In conclusion, the anticipated service life of the proposed galvanized 5 gauge metal plate structure for Washington Park far exceeds the 100 year threshold. The projected 289 year service life is hard to fathom yet the formula has been validated by two studies, a California study which is briefly cited in the AISI Handbook (pg 6) and extensively discussed in the Parson Brinkerhoff study. The primary factor contributing to the lengthy service life is the thickness of the metal plate and its associated thicker zinc coating. The apparent reason for galvanized corrugated metal pipe having such a checker history regarding its service life is two -fold: 1. The pipes were typically small diameter (relative to the 25-foot diameter proposed for Washington Park) and as a result, the metal thickness was quite thin (16 to 12 guage) which came with a commensurately thin zinc coating. 2. The pipe invert was the primary location of failure due to abrasive flow and constant exposure to water. The Washington Park structure will have an earthen invert, thus the most critical location for failure is non-existent in this application. Let me know if you need any additional information regarding the Washington Park proposal. I can be reached at 760.285.7335 Sincerely, Steve Speer, Principal SPEER Civil 50855 WASHINGTON ST ♦ SUITE C-280 ♦ LA QUINTA ♦ CALIFORNIA 92253 Office. 760.285,7335 Fax: 760.269.3580 w speercivil.net INTRODUCTION Corrugated steel pipe (CSP) storm water deten- Bon systems (plain galvanized, aluminized, or bitu- minous coated) have been in use in the metropolitan Washington, DC area since the early 1970s. A qualitative condition survey to assess the overall performance of 17 of these systems was conducted by Parsons Brinkerhoff of Baltimore, MD on behalf of the National Corrugated Steel Pipe Association (NCSPA) in early 1998, The overall con- clusion of the survey' was that the systems were performing extremely well. Figure 1 shows the average condition rating (crown, sides, invert) based on a visual rating scale developed by Corrpro, 1991? Most systems still had the zinc layer intact after about 25 years of service. There were no signs of visible deflection and mostjoints appeared to be soil tight. In May of 2000 the NCSPA retained Corrpro Companies Inc. to perform a more detailed and quantitative evaluation of the corrugated steel pipe storm water detention systems evaluated previously. This work includes determining coating. or metal loss and using available methodology to predict service 1 2 a 5 a 7 a 9 12 is 14 15 16 17 is 20 21 Site N unimmuu 3uvoy or uamgaim sieei ripe uetenoon Sy5lnm5, NCSPA, Washington, DC, March 1999. "Condition and Conosion Survey: Soil Side dwablity of CSF." Conpm Companies, March 1991, life. This report presents the findings of the study undertaken by Corrpro. EVALUATION PROCEDURES Fifteen of the 17 Ales were selected for evalua- tion. Sites 15 and 20 are sand filter systems and were not evaluated because access to the invert would require removal of sand filer media. During the field inspection it was found that one of the systems (Site No. 12) had been removed during redevelopment. In addition, it was not possible to gain access to two of the systems, sites 1 and 18. Thus testing was per- 1 Table 1. Stormwater Detention System Overview Pipe Pipe Sal Depth Site No. Location Diameter Coating Corrugation Age to Top of W9. , - (inches) (years) Pipe (feet) Soil Wfater Coupons 2 Industrial, Montgomery County, MD 48 Galvanized lx3' Helical 26 2 2 2 3 3 Industrial, Montgomery County, MD 48 Galvanized lx5" Helical 26 4.25 1 2 2 5 Industrial, Montgomery County MD 60 Galvanized 1x5" Helical 21 4 2 2 2 6 Commercial, Montgomery County, MD 96 Galvanized ix5' Helical 21 4 2 2 2 7 Commercial, Montgomery County, MD 96 Galvanized 1x5" Helical 21 2 2 2 2 8 Commercial, Montgomery County, MD 72 Fully Bituminous Coated 1 x5' Helical 21 2.5 2 1 2 9 Commercial, Montgomery County, MD 72 Galvanized ix5" Helical 21 13 1 1 2 13 Commercial, Montgomery County, MD 108 Aluminum Coated Type 2 lx5' Helical 11 6 2 1 2 14 Residential, Fairfax County, VA 67x104 Fully Bituminous Coated lx5" Helical 6 6 2 2 2 16 Residential, Fairfax City, VA 80 Aluminum Coated Type 2 US" Helical 11 11 1 2 2 17 Residential, Fairfax City, VA 65x101 Fully Bituminous Coated US' Helical 6 12 1 2 2 21 Residential, Alexandria, VA 144 Galvanized Ix5" Helical 6 6 1 2 2 formed on 12 sites. Table 1 presents an overview of each site including the numbering, location, land use, system size, age, and sampling performed at. each of the sites. Field Testing Field-testing cormsted of performing viwal observations, m-siur measurements of soil resis- tivity soil pH, and redox potential at each she. Disk coupons (Th inch in diameter) were obtained from the top and invert at each location for subsequent determi- nation of the remaining zinc layer thickness. A total of 25 coupons were collected. Soil and water samples were also collected from each she for laboratory analysis Wherever possible, photographic documentation of the detention systems was made. Laboratory Work Samples collected from the field testing were evaluated in the laboratory. Corrugated steel pipe coupons were polished metallographcalty along their thickness to reveal One zinc layer. The zinc layer thickness was measured at ten locations with the help of a low -powered optical microscope and an average thickness was calculated. Soil samples were Table 2. Field Test Data Site No. Location Bottom Top _ Bottom Top Surface Bottom Top 2 Industrial, Montgomery County MD 4000 7000 -681 -637 -508 6.85 6.74 3 Indusmal, Montgomery County MD 4000 4000 -562 -620 -549 NM NM 5 Indmtrial, Montgomery County, MD 6500 11000 -644 -694 -633 NM 8.14 6 Commercial, Montgomery County, MD 13D00 6000 -786 -740 -689 6.85 lim 7 Commercial, Montgomery County, NO 20000 3300 -741 -546 -722 T 24 7.86 9 Commercial, Montgomery County, MD 5WOB NM -641 -690 -724 NM 7.38 21 Residential, Alexandria, VA _ NM 1900 -629 -706 -671 6.27 6.49 " 8 Commercial, Montgomery County, MD 20M 2000 -938 .721 -946 NM NM 14 Residential, Fairfax County VA 11000 7100 -973 -481 -955 7.14 8.67 17 Residential, Fairfax City, VA 15000 6000 926 -946 -933 7.16 6.8 13 Commercial, Montgomery County, MD 10000 5500 -664 -672 -425 10.4 10.1 16 Residential, Fairfax City, VA NM 28000 617 -665 -613 7,81 8.01 'Soil resistivity determined with a Collins Rod "CSE = capper sulfate electrode NM Not Measured evaluated to iderAoy the soil type and physical char- acteristim determine resistivity, pH, moisture comem, chlorides and sulfides. Watersamples were evaluated to determine pH, resistivity, chlorides, and sulfides. FINDINGS Utilizing the soil and water analysis data, the pre- field Tests Tab dicted service life of the detention system was calve- soil resistivity, p lated using a variety of methods: at each site. Over ■ Software previously developed by Corrpro found to be in t Companies' for the NCSPA with respect to ■ California Method for Fstunafinq Years to Potential readings Perforation of Steel Culverts ized layer ha n AISI Method for Service Ufe Prediction the bare steel. Best Service Life Prediction Model Table 3. laboratory Sal Analysis Data and Soil Side life Prediction" Sample Mast[" Site No. Locatim Soo Type Sample Color (%) pH 1221 2 Top sandy clay gray 23.72 7.4 Invert loam gray -brown 27.32 7.7 3 Tap clay gray 29.14 7.9 5 TOP silty loam gray -brown 23.83 7.9 Invert clay gray -brown 26.51 7.4 6 Tap silty clay light red brown 27.52 6.4 Invert silty day light red brawn 29.18 6.8 7 Top silly day loam light red brown 23.67 6.3 Invert silly day loam light red brown 30.21 6.6 9 Invert day gray -red brown 34.OD 7.6 21 Top silty day light red gray 24.17 6.0 -� 8 Tap silty clay loam yellow gray 25.58 7.7 Invert silly clay loam yellow gray 27.48 7.6 14 Side silly day loam IigM gray brown 23.07 5.7 Invert calidm light gray brown 32.38 6.6 17 Invert silty clay light red brown 27.95 5.1 13 Side silty cla It M red brown26 7 u The procedures used by Potter in FHWA- RP-91-006. le 2 summarizes th H and potential mea 80%of the potenti he range of -617 a copper -copper su 9s in this range indica s not corroded awa in ANALYSIS AND DISCUSSION Table 3 summarizes the laboratory analysis data for the soil samples. These parameters were utilized to calculate the remaining life of the galvanized layer e resulls of the using the software program previously developed by suremems made Corrpro for NCSPA2. That study of culvert and storm al readings were sewer installations concluded indicated that "93.2%of to -946 mV the plain galvanized installations have a soil side serv- Ifate electrode. ice life in excess of 75 years, while 81.5% have a soil to that the gal. side service life in excess of 100 years." y and exposed The software generates service life predictions from a statistical model developed to accurately pre - Per Parsons Brinkerhoff conclusions 7pg8,the AISI Method was found to be a m accurate service life prediction model Chloride Sulfide Resistivity 16 gage galvanized Cage Predicted (wpm) (Ppm) (ohm an) pipe fife (yrs)' Multipfier pipe life a a 16 0.3 722 91.5 1.0 91.5 60 0 1684 70.9 1.0 70.9 32 0 2538 100.11.0 1.D 100.1 20 0 8696 141.4 1.3 183.8 27 0 3663 91.7 1.3 119.2 37 0 4630 57.4 13 74.6 28 0.3 5051 67.7 1.3 88.0 42 0 2941 50.4 1.3 65.5 9 0 11765 122.9 1.3 159.8 10 0 2899 139.7 2.3 321.3 34 0 1992 45.4 1.8 81.7 32 0 30 0 10 0 10 0 12 0 y g 3 6.6 30 0 Invert silty day light red brown 34.33 7.2 18 0 16 TOP silly loam light gray brown 20.40 4.9 16 0 .Service life for 16 gage galvanized pipe using sollware Previously developed by Corrpro Companies, Inc fa NCSPA 2899 94.9 1.3�rC3123.4 3846 96.8 1.3 125.8 7813 79.9 1.8 743.8 10417 115.9 1.8 208.6 6993 59.3 7.8 106.7 1961 60.6 2.3e 139.4 3745 100.1 2.3 230.2 10417 54.0 1.3 70.2 3 dict service life of galvanized CSP for sites where durability is limited by soil side corrosion. The model predicts the condition of the protective galvanized coating over time plus the life of 16 gage blade steel. According to the author: "When the galvanized coating reaches the point that pitting of the steel substrate could begin, the model uses black steel corrosion data from 23,000 black steel underground storage lank saes to analyze overall durability vs. time. The black steel used in the model was 16 gage. Therefore the model does not accommodate added life projections due to the increased thickness of the pipe wall. Use of this data induces significant conservatism also, because, it B based on steel not previously galvanized, and there - Table 4. Service life Predictions in Accordance with the California Method and AISI Method Sample Resistivity California AISI Fired. Minimum Minirwm Site No. Location pN (ohm -an) Gage Pred. Life (yrs) Life (yrs) California AISI ,• .�, Crown Sod 7.4 722 16 28 57 57 Invert Soil 7.7 1684 40 80 28 Water' 5.5 613 5 10 3 Crown Soil 7.9 2538 16 48 95 31 62 Water" 7.5 881 31 62 5 Crown Soil 7.9 8696 14 97 205 34 73 Invert Soil 7.4 3663 68 144 Water 7.4 692 34 73 6 crown Soil 6.4 4630 14 33 69 32 67 Invert Soil 6.8 5051 39 82 Water 6.2 5181 32 67 7 Crown Soil 6.3 2941 14 27 58 27 58 Invert Soil 6.6 11765 44 93 Water 7.3 3165 55 116 9 Invert Soil 7.6 2899 10 108 231 94 201 Water 7.9 20M 94 201 21 Crown Soil 6.0 1992 12 29 61 29 61 Water 6.2 8333 50 106 8 Crown Soil 7.7 2899 14 62 130 62 130 Invert Soil 7.6 3846 69 147 Water 7.6 3135 64 135 14 Side Soil 5.7 7813 12 44 94 44 94 Invert Soil 6.6 10417 59 125 Water 6.9 4184 54 114 17 1Men Soil 5.1 6993 12 38 80 38 80 Water 6.6 12195 61 130 13 Side Soil 6.6 1961 10 47 100 47 100 Invert Soil 7.2 3745 84 179 Water 7.3 4016 100 214 16 Crown Sal 4.9 10417 14 30 64 30 64 Water 6.8 5814 40 85 Notes: 1. The above resistivity and pH data was obtained from laboratory analysis of field samples. 2. All predictions are for galvanized pipe of the designated gage. No multiplier or "add -on" for additional coating has been used -This water smelled of antifreeze. It was considered an aberrant condition for service life prediction. "This •Water" was saturated organic matter. fore, does not recognize the effects of residual galva- nizing and the alloy layer formed during the galva. nizing in slowing the corrosion process. Additionally, the slowing of the. corrosion pitting rate with here for thicker gages cannot be accommodated. However, these shortcomings add conservatism to the service life estimates." The calculations show the average predicted life of a 16 gage galvanized pipe in these environments is about 86 years. Table 3 also attempts to adjust the. service life prediction by using a gage multiplier as recommended by the AISI Method. This shows that the average predicted life of the systems is about 130 years. The minimum predicted service life for any of the systems is 65 years. Taking all of the above fac- tors into consideration, the total service life of the structures would be in excess of 100 years. Table 4 shows the predicted service life of each detention system using both the California and AISI methods. The California Method was developed by Stralful to predict tlme to fist perforation, which is not considered the end of service life. The AISI Method (also developed by Stratful) is based on the Caltrans Method but ls used to predict average invert service life? For each method, the service life was calculated using each of the environmental samples (soil and. The minimum of the calculated pgse is then identified in the table. Notice that systems 2, 3, and 1 are very near the end of the California Method predicted service life (first perforation). Yet the systems are all in quite good condition, with most of the galvanized coating still in tact. There would cer- lately need to be extreme corrosion to occur if they are to have penetrations at the age predicted by the California Method. This suggests that the AISI Method provides a more accurate service life prediction than the California Methodfor detention systems, however both methods provide very comervative predictions for these environments. Figure 2. Percent Metal Perforation vs. California Prediction O e.ro.uad Oystmu f r wl,fiwy &umimaCwlea SYuewtr �'�`� i AYBiemnt9iletl '. �,-=lamx lOeNabeU sysbad �: "-�(fa8y aiia..min faetea systwy,,<< *razsysiax,�: 0% 10% M 3016 40% M 00% 70% 805s %% 100% Percent Metal Perforation ""Durandry of CSP," Richard Aratful, Corrosion Engineering, In[., 1986. 4 Durabiry of Spenal Cnaliogs for Corrugated Stuff Pipe, 1.C. Cotter, I owandowskl, and D-W White, Federal Highway Administration, Repot No. FHWATO 91006, June 1991. n Table 5. Service life Ana sis Using the Technique Developed by Potter Percent Nfm. Calif. Percent of Site No. Original (esQ Min Perforation Prod. Years' Years Calif. Pred. i 2 0.058 0.048 172% 28 26 92.9% 3 0.058 0.056 3.4% 31 26 83.9% 5 0.072 0.069 4.2% 34 21 61.8% 6 0.071 0.044 38.0% 32 21 65.6% 7 0.071 0.068 - 4.2% 21 21 77.8% 9 0.128 0.126 1.6% 94 21 22.3% 21 0.099 0.097 2.0% 29 6 20.7% 8 0.075 0.071 5.3% 62 21 33.9% 14 0.096 0.096 2.0% 44 6 13.6% 17 0.105 0.099 5.7% 38 6 15.8% 13 0.124 0.120 3.2% 47 11 23.4% 16 0.070 0.053 24.3% 30 11 36.7% 'Doe from Table 4 of No report To better understand the relationship between the crown of the pipe where the galvanizing was melallo- Using all data points, the analysis suggests that the California Method predictions and existing conditions, Potter correlated percent penetration with percent of California predicted service life expended.4 While there has been extensive debate over the validity of the technique, it is used as another method to com- pare service life predictions. Table 5 presents the min- imum thickness measured on coupons from each system. That value is compared with the 'original' thickness. The original thickness was determined in most cases by measuring overall thickness on the graphically determined to be in -tact at nominally the original thickness. System 6 was the only system where an original thickness was difficult to determine, but a sufficiently conservative estimate was made based on measurements of the coupons. Figure 2 shows the data platted in a manner similar to that used by Potter. Best-fd lines were regressed through all of the data for galvanized and asphalt coated pipes. No plot was made for aluminum mated pipes due to a lack of sufficient number of data points. galvanized systems are performing 2.8 times as well as the California Method would predict while the fully bituminous mated systems are performing 4.6 times as well as the California Method would predict for gal- vanized material. It should be noted that this multi - Fiber increases to 7.3 times for galvanized systems d She d6 is ignored. The inspection of the systems sup- port the conclusion that the galvanized detention sys- tems will last more than nuke as Icing as the California Method might predict 1. Corrugated steel pipe storm detention Systems (galvanized, aluminized, or bituminous coated) are performing satisfactorily in service. 2. The service life of detention systems appears to be driven by soif-side corrosion. 3. There is no significant water -side invert deterio. ration. As a result A is expected that the service life would be longer for detention systems than for culverts or storm sewers. This may be the in part to an absence of abrasion in the invert of detention systems. 4. The AISI Method appears more realistic in terms of predicting Detention System Service Life than the California Method, though both will provide conservative service life predictions for most environments. S. Visual observations and measurements of remaining galvanized layer thickness on coupons are in concurrence with theoretical cal- culations using previously developed software for remaining life prediction. S. Physical inspection of these systems along with the analytical approach presented herein support the prediction of a functioned service life for these galvanized detention systems in excess of 100 years. Service Life to Exceed 100 yrs 7. Corrugated steel pipe manufacturers provide a range of coatings and material thicknesses that make 4 possible to design a dmendons system in. practically any environment Nat will last in excess of 100 years where corrosion is the life limiting factor. 48.. etentiora /i °fiitri"Ition System'. Montprnery County ` 61 pH 7.41! ' Chlondr ppm 193 Sulfide, ppm 0_.. Resistivity, ohm -cm 692 - I Moisture% 23.83 26,51% pN 7.4 7.4 Chloride, ppm 20 27 Sulfide, PPm 0. 0 (. Resistivity, one Can 8,696 3,663 Age of Inspection: '. 21 years Coating Type: galvanized Diameter: 60" Corrugation: 1 KY helvai Land Use: industrial Lion. Montgomery County, Md. n .A "'�',v 3�.e" 1 .94 . .C,-v a. .t » x. x .Gei. c , ry m .. -^: • • v a iw...x _ (l " Detention System, 110, ontgomery COUnty m: PH 7.6 n� Chloride, from: 40 Sulfide, Dan 0 Resistivity, ohm -cm 3135 a n ".f Moisture%, 25,58 2748% PH 7.7 1.6 Chloride, from 32 30 CROWN: sou SIDE INvi:RY. SOIL SIDE Sulfide, plain -H 0 Resistivity, ohm -cm 2,899 "'3846 CROWN, WATER SIDEINVINT: WATER SIDE Age of Inspection: 21 years re Coaling type: fully bituminous coated Diameter 72 „�- Corruption: 14'helical g'2 Land Use: industrial Location: Montgomery County, Md. 71M 108" Detention 'S"Vs, 1. m, Monti ornery Ccuri :. rv:•Lt arr6Wf+`ki+�rilkkik� vV:�88C�FN= 15 PH 6.9 Chloride, ppm. 32 Sulfide ppm 0 'Resistivity, ohm cm 4,184 Moisture°% 23,07 32.38% PH 5.7 66 ,1 Chlonde ppm 10 10 I Sulfide ppm -, 0 0 t Resistivity. ohm run 7,813 10,417 x. Age of Inspection: 6 years Coating Type fully bduminous coated Diameter 67"x104 Corrugation:. 1x6"helical Land Use: residential " : Location. Fairfax City, Va. E � ,7 7 7:'!-., Detention SNfstetri, Alexandria CONSTRUCTION PRODUCTS INC. Darwin Dizon, P.E. Regional Sales Engineer June 2, 2006 50855 Washington Street Suite C-280 La Quinta, CA 92253 751 S Weir Canyon Rd #157621 Anaheim Hills, CA 92808 Tel: 714-281-7883 Fax: 714-281-7884 Email: dizond(cDcontech-coi.com Subject: Corrugated Steel Pipe Underground Detention System Service Life Dear Mr. Speer, Per your request, I have compiled supporting information regarding the durability performance of corrugated steel pipe (CSP) for underground detention system. I am available to discuss this further if you need more information. CSP has been around for over 100 years. It has along history of application for culvert and storm drains under highways, streets and railways nationwide. Due to its lightweight, proven structural capabilities and long service life has made it a wise choice for stormwater underground detention system. The corrugated steel pipe has been used in underground detention system since in the late seventies; performing as designed and projected to last in excess of 100 years (see attached "Service Life Evaluation of Corrugated Steel - Storm Water Detention by CorrPro Companies Incorporated). Durability: CSP or steel structural plate (a.k.a Multi -plate (MP)) used in underground detention vastly differs from culvert application. Underground detention MP behaves more like tank storage. It is not subjected to fast flow velocities and bed load abrasion that can compromise the protective coating. MP used in detention system only sees minimal flow velocity and only experiences the rise and fall of the water level. The protective coating stays in tack providing a long maintenance free service life. I have included a copy of Chapter 6 "Durability" from the Handbook of Steel Drainage & Highway Construction Products by the American Iron and Steel Institute (AISI) for your information and highlighted the important sections. Figure 6.7 was developed for estimating the invert life of CSP for 0.052" to 0.168' steel gage thickness with 2.0 oz per square foot of galvanized coating. Pipe inverts take the most wear and tear in culvert or storm drain applications. This chart is often used for MP durability evaluation also but yields an overly conservative estimate because the plate has 3.0 oz per square foot of galvanize coating and often thicker than 0.168". Per Sladden's Geotechnical soils report, the soil pH is 7.5 and resitivity values of 1533 ohm -cm. The expected service life of 0.168" (8 gage) thick CSP is 202 years per Figure 6.7. should be 0,41 per AISI formula found on page 7 of the section entitled "Gslvanlzed Durability Info"_ Figure 6.7 Years = 2.94 041 (based on .052" steel) Please note however, the calculations are correct, the formula was simply printed incorrectly. I % ® de r' CONSTRUCTION PRODUCTS INC. Years = 2.94 x (1533) 041 Years = 59.5 years Using 3.4 thickness factor for 8 gage the anticipated service life is: Years =59.5 x 3.4 = 202 years The proposed multi -plate structure is 0.218" (5 gage) which is thicker than 8 gage and has thicker coating also. Using the regression equation below to determine the thickness factor beyond 8 gage, .where x = gage, the expected conservative service life is 289 years- 5 gage thickness factor: Years=(-)3.0502LN(x) + 9.7614 = 4.85 Projected 5 gage (0.218") plate expected service life is: Years = 4.85 x 59.5 = 289 years Other Durability Considerations: • The arch steel MP durability is soil side dependent since it is a retention tank and not a culvert subject to continual flow. • The arch MP retention has an open bottom to allow for infiltration. There is no steel invert to maintain or wear out. • The structure is a shell holding back the backfill to create the storage required and has limited water exposure. • The site is in an and area and the extra protective coating is not required. • Per Sladden's soil report, the soil within the upper 30 feet is dry indicating moisture content below 20% which helps minimize corrosion cell from forming. The arch MP will be installed within this depth. • Nuisance flows are routed thru the concrete end walls thus minimizing contact with the structure. • Ground water is deeper than 50 feet providing a dry backfill environment around the structure. Conclusion: The site condition is favorable for steel use. The proposed 25'-0" x 12'-6" 5 gage (0.218") galvanized arched multi -plate structure is a perfect fit for the underground retention design because it is durable with proven structural capabilities. The CSP durability guideline was established thru critical investigate research of more than 50,000 installations. The structural integrity has been proven through the acceptance of following major agencies: • Caltrans • The "Greenbook" Standard Specifications for Public Works Construction • American Association State Highway and Transportation Official (AASHTO) • ASTM Standard Practices. m U �\l 0 W W 4-4 b.! cd 0 � 0 o 0 cd N �T bLo 0 cd N r 1 Y4 1. Z V t/; f 7 !^ u N CL • .'1 __ - n N tv.r. i v.v v 'C = C' j v IY � °�❑ �v v H � L '1 v U ❑ 61 J .n � � J y � � G 4! � � C z i � U� � :. r .. G rn ❑ Cdi J r. C a p: � L UI n !• L � � C' `. n DO S n E j5 if, C !p .-7 v. C- � i �. 0. - � � r ❑ r Y� 7 f:5 r: n � � (p A .7 Oan=0GEL -On n p R fL Rr ro q nP.r O...j `i? a�° O= Rti= =S.F io-�O.ab - . n rria ..�� do - ��- n G O �.`wG O T_ R ✓I L n [3 Ej F n tE rjj II� L � -di d 6 y .�- �.✓. � R , V) •p n F p N n w � Qi c E3 9 J c 7 Q O. rra d r ... r L M1 Z �. n✓ .y nC ry C r r� n� n rt n :.ti rt�' f v O rt J= cap w r✓` 'off J z c o f - _GG=N=�fla�dna — f r': NP m5, a?' 7F—� c-c ❑� ^zs anA si. oc r -`_ rs r " F "i-'lw�oa— �` C.4 �r Nra n. a v O 4. ? , a r. . C. f i O y. ✓. < (C '� = r i= O p a f 6 C ... -. O =h z a.{ ", R C '✓. lS6 O O' rr rtc_i f r - vc a. 5'c C v--, R v _ `_J q 7 r c '< p Q. 0: p. ti N ... y rt`_ r r rn 0 v: t� o .#Oi 5 tir'c C. C CI a ��'n.a c aY. h� ov E❑ — r u n 't7 rogM2 -'� (^ k" arc pc. -no is Nac Y a to �wn, O..'- TJ 'rn=rc '� ... p r � t•:. ry � _. G � .+ q a � � Q. � r. ro ='. :. L Y; � � �, .. i r, � in -f0' � R R C r > !`G-. N O- z i 4 a fi f➢ = rO `l. < C p ry P p � r rK J� .� p. .� _ O < �. � a RO O 4 a °r'. m --_ —' B, ` frt O? � PO� A v s4G a r� G Sl^ �.:'"G^ A .+ 7' �ry IJ •'] f' C=i �q . � O S i°i `^ 2i F { f ! q =n � n �' 1 O � = ✓ C' F.. _ =',p p rc !ry ^'� O sT sa �:.+. O ro 0 � r a J � at o _ H a E Thickness —inch 0052 0.064 0,079 0.109 0.138 0168 Gage 18 16 14 12 10 8 Facto!' 1.0 1.3 L6 22 2.8 3A Moist, Years by Facto, 10, the Yatlnne w1al mmxness pH of Environment Normally Less than 7,3 Years — 27.58 Log top -Log to (2160-2490 Log pH of Environment Normally Greater than 7.3 Years — 2.94 R 041 R = Minimum Resistivity 1.000 Minimum Resistivity (R) ohm Cm 0 10,000 Figure 6.7 Chart For Estimating Averago Invert Life For Plain Galvanized Culverts. 100.W0 — N J J — > LQ' 9 'J C J J _ J a _ vi 9 J, - E ? 44 -J mil) , z= qJ » L tj co f T L rl n) G 1 ^J ? CI U J J � � G - ❑ -.: � v Jam' L� _. - - �A® Lj \W� C^ LLJ C[ cz LZ ® I lF i u r f � a (7NNNN� _-.78.7 H N000 � 0 C 0 L N P N i in- lq �O _ 3�4.9._ 'N�+ Zd S' 15I _ J✓r _ir ��U N 0 . i► r- Gl,o,l CNNIC.gI_INVF TIGATION PROPOSED TARGEF STORE & SURROUNDING RivrA i. COMPLEX SOUTH SIDE OF H[GHWAY I I I JIF. FWEEN WASHING'FQN C ADAMS s-i ia. TS LA QUINTA, CALIFORNIA -Prepared By- Sladden incerm9 c4milld Lain. Sultc G Palm DeWrl. Ci lifomm 92211 _- - - -- �. _. SY�uIJ�n Iv+giuc'arin,�• SCH'Slll CONDITIONS ( he ne:u urtaec soil; 016serveil IN, IIII III Inlr bolln'-'s nmskI nrimilrih, ill lfill, '>riined sill" ,ind, and sandv ml I -Ili: ,;Ills svllhnt the npper 30 feel eon,Isicd prhnanly of luu s!rained silty ccllcr.ill� thin sill Ian_ cl.; it ,Icncral, (he Sitc solk.Ipjmllcd colllc\\hai Igoe lhi a ,hcut die Iiphrr'i to 10 !rrl fill Iabolatot" teat rc;ull, And sampler prnuuaiiou IcSISIall(:e ta; measured 1" 11,l 11,1"I"Ccuitsl sI �csl lh:❑ the Slle .oils rciwl,lily become lirmer Nvith depth. Lahoi,uory IC'i lne pel lot lmsd in ichilively undisaurhed samples ilidictncd dry density van ins hour S, to 1 13 pounds per euhie iot'l 1pc f), i lie site xnis ,scfe !loud to be dry fhroupitoul the majority of otu b+NiLf"s but sonic, of the deeper sill I'r elss c.cre ,4 r1 I ,Ihoratory leslill indicated moisl I I c contcilt varvife, atom Immca 'Al ra h le to 2Q petcelit. L'Ihig3lol'N clattsi(iaainn Icsiing 01111cates that the neat sill tacc sail, c,In>isl IMIleuih of ;onsc:vhat ;ek"11sislent combination of s(h� s-uitds and sandy I;Ihs- litpnnsion tcstim, indicates that the weyrity of the surface soils are Alssilled as null -expansive and fall within the "vcl} loNN espaiuiou eutegory ut accordanec with the Unil 13uildin, Code class ication system, Consolidation (esti❑ - indicates that the oetir ,urface silty sands and sandy sills ale potentially compressible and may he swocuplibie to detiinlcntal irydloeon>olidatiou end'ortontpies>ion related setlicments. Gnnnrdu.aer was not cneountelcd within our borings that alanded to a ntasfnwm depth of :Ipproznu:uelp i0 Deer bAmy the cei,ting f,rcniucd .ultace hilt yirollodI a cr should rnrt he a I"Ictor in louiidill"n design ,ir aPnST; ll'lion. CONCLUSIONS ANll 12T:CO1lViFNlhy'1IONS I't vd upon oul field :Intl d.iboraw s imesii,�ntoll, it is slur opinion IhA the proposed I I ,, Sinr� and :;uii>undinL' o2.u1uonunetf Alidesclilpm::nt ;lie lc�lsibde noill a soil mechanic, st idpoini pl prided thst file rccominendalious inl,ludud In [Ilu; report are considered uI huildilt", fi,undalion de<iu❑ alid sno plcparuion. Due to 11w sonlcishai Ino.:e and wmpiessil le conditions of the near,aililc. >,,>Ils, rcotedi:d ill;ildifw in,audLlg oorevuaNation and mcompaowt, is recommended ILL the proposed btuldulg:n-cas. %Vc WL011nnfnd 111n1 ICIiedL9l grudin;; Is�ithilt the pluposed building altos include q,-ertseacalion chit recOml'l,Iclion of thr loo,e ;uiface soils aid the primanfoundation heroin,_ will Specific Ircouuncndalions fol .lie prparniwn are presrnfcd in the Sae GIAIIIn''let Iion Of this repolI Cn�nnrch•, at r teas not cncounicred I% thin ouf borins that estertdcd to :t depth of approsinrurh 50 lest helow the cxnunz "found r,nrlacc. Duc to the deiuh Io �,rUund�a:ner, Spcci fie Iiquclaction ,m:IhsrS acre not pCilvilued Kv'ed upon the depth to <,roundn•nter anii the prominence of non-Ilgnetlable sills under t•. me the site. the poii'nll:Il till liqucf51iiou and tilt related surllcial :ilterls of liII11wh rioa impactin" the.ih� ore cgnsidrretl ue�ili^_il'Ilc. I II. 'ill: is looted v.fill in an active $eisliliC :ueo of SQU(Iter11 Califol11io s%ithln 31)1..,:,i1Iiatc1% 4.1 Likuneicrs ref the tiara Alldle,Is Pauli system. .St emg ground uruio❑ �iom ca!dIgo c activity .tinm the nesrbs S:m Alld I:1, of San Jacinto fitull systems Is lil.uk, to Impact die ;ilc dune" the altucip:?Ied li(clitnc of 111c ,Inamrc" $tt'ueime; should be dvslf'ued It_y prof ssiknil CUItlbtu tNilh Ilse 11 1-Ji and seisloic .ciliuc of the Siie. A,s a minimum_ ;iluc-iun ilf.:i-.0 should ..00hirnl uI Ur,ifonn klltldln,: Code IIl13(') Icyuilcmr ills to] Sci9ulic. Lone -I_ Pelt nrnl sekwlc de lw I .ru,-w a,, outlined iu Ih, I'1'( r. •;Horn cn lied iu Ap[wlldi. (' „f Ihi; icpfat. ANAMIM TEST LABORATORY 3008 S- ORANGE AVENUE SANTA ANA. CALIFORNIA 92707 PHONY. (714) 549-7267 sTANrCUN Av. SUITE I' , I pjjj,:[,jA PARK, ('A- 90621 ® A.T`Pid: i3RE:1`TjDP.vr: pp()j EC,r: # 514 2 106 0-5, 0 ANALYTICAL RFPOPS CORROSION SERIES SUMMARY OP DATA 0 Vii SOL�jBf,F, SULFATES CHLORIDES 0 per ca. 41-1 pet 422 ppm ppill 49 630 0 0 DAW! -/ / i / ()2 PO.Nl Chain of (%is--odY SNpDet No. LCI)NO A-17P2 spe,cifirminn Mcnericl: SOIL r,jpq. PFISTsTil , 'ITY per t. (A3 011111-c'n 1,533 Clem 5 GA. STRUCTURAL STEEL PLATE ® should not be compared to . . .,9GA CORRUGTEDSTEEL PIPE ® 5 GA. IS 0.218 IN. THICK ® 1A �' isaos ix. mice ® 5 GA. STRUCTURAL STEEL PLATE is 0.218 inches thick while 18 GA. Corrugated ® Steel Pipe is only 0.052 inches thick. The title information appearing at the top of the ® page, complete with comparably sized fonts for the two materials, was provided to ® establish a strong visual representation to the significant difference in the size of the material. The solid black lines shown above precisely represent their respective ® thicknesses. ®� Comparing 5 ga. Structural Steel Plate material to 18 ga. Corrugated Steel Pipe is like comparing a 218 pound NFL linebacker to a 52 pound third grader in Pee Wee football. ® Both are human and both play football, but there's a big difference is size and strength. ® One square foot of 5 gauge Structural Steel Plate weights 8.9 pounds ® One square foot of 18 gauge Corrugated Steel Pipe weights 2.1 pounds ® These two materials should not be lumped together and compared on equal terms with ® respect to performance simply because they: ® 1. Both use the same cathodic protection method, and ® 2. Both use a corrugated scheme for structural strength ® The performance of these two materials is significantly different because of the ® difference in their size and strength, and ...... the most highly recognized authorities ® in the civil engineering profession such as the US Army Corps of Engineers, Federal ® Highway Administration (FHWA), and Caltrans authorize the use of these materials in ® publicly financed infrastructure. ® In the final analysis, the performance of 18 ga. corrugated steel pipe should not be used ® to judge the performance of 5 ga. structural steel plate which has proven in multiple studies to be significantly stronger and more durable. ® Table of Contents ® Executive Summary ................................................................................1 ® Sample Structure....................................................................................2 ® Service Life ® Definition......................................................................................3 ® It's a Design Parameter................................................................4 ® How to Estimate Service Life........................................................5 ® Inspections Assure Public Safety.................................................6 ® Reference Material CD with reference documents ® Army Corps ® FHWA ® Caltrans ® LA County Executive Summary Do any public agencies use galvanized structural steel plate and galvanized steel pipe? Absolutely! The use of these two materials is clearly in the mainstream of engineering practice. For example starting at the federal level, the US Army Corp of Engineers and the Federal Highway Administration use, or advocate the use of, galvanized structural steel plate and galvanized steel pipe. These two federal agencies have produced extensive publications and manuals to guide engineers in the proper use of these materials. Moving to the state level, Caltrans is a major player and research agency regarding these two materials. They have devoted an entire chapter in their Highway Design Manual on the procedure for using these galvanized products, and their research and documentation is widely used and referenced around the country. The Los Angeles County Public Works Department allows the use of corrugated metal to construct detention tank facilities using pipe, or vaults, as a means for mitigating and controlling water quality in urban storm water runoff['). The cities of Palm Desert, Palm Springs, and Rancho Mirage all allow the use of galvanized metal in constructing storm detention/retention facilities. (a) Los Angeles County, A Manual for the Standard Urban Storm Water Mitigation Plan, Appendix B.6 Page 1 of 6 Sample Detention Structure This Structural Steel Plate stormwater detention facility was constructed in Maryland. Judging by the size, it's a significant investment in structural steel plate. Page 2 of 6 Service Life — Definition Caltrans defines service life of a drainage facility as: the expected maintenance free service life of the installation. To which they add: For all metal pipes and arches that are listed in Table 853.1A, maintenance free service life, with respect to corrosion, abrasion and/or durability, is the number of years from installation until the deterioration reaches the point of perforation at any location on the culvert. (1) 1. Caltrans Highway Design Manual, Chapter 850, page 850-1 Page 3 of 6 Service Life — It's a Design Parameter There is no question that Structural Metal Plate material can exceed a 50-year service life. In fact, there is no question that Structural Metal Plate can exceed a 100-year service life if you select a material that is thick enough to do so. Caltrans considers a 50-year service life to be the minimum length of time for the critical installation locations and they allow the designer to select the thinnest material thickness that exceeds the 50-year threshold.121 It should also be noted that 50 years is the longest service life they require for any drainage structure.(2) There are some locations where they allow a service life of only 25 years. In Caltrans design guidance text they state • Under most conditions plain galvanizing of steel pipe is all that is needed; however, the presence of corrosive or abrasive elements may require additional protection.(3) • Added service life can be achieved by adding metal thickness. However, this should only be considered after protective coatings and pavings have been considered.(4) 2. Caltrans Highway Design Manual, Chapter 850, page 8504 3. Caltrans Highway Design Manual, Chapter 850, page 850-14 4. Caltrans Highway Design Manual, Chapter 850, page 850-15 Page 4 of 6 s • 0 0 o / Service Life — How to Estimate Service Life o` • The US Army Corps of Engineers (5), the Federal Highway Administration (6) and o Caltrans(7) all use the same basic chart to estimate the service life of galvanized metal o products. It should be noted that when FHWA wanted their publication produced, they turned to the US Army Corps to produce the document. The Army Corps included Caltrans' service life chart in the document they produced for FHWA. They also o included the service life chart produced by the American Iron and Steel Institute (AISI) o which is essentially like Caltrans' chart except Caltrans used a factor of safety of 2 to • cut the AISI service life estimate in half. • The service life estimate is a function of electrical resistivity in the soil, soil pH, and the • thickness of the metal being used. 0 For example, if 5 GA. Structural Steel Plate is placed in soil that has 1533 ohm -cm, and a soil pH of 7.5, the service life is greater than 101 years. The 101-year estimate is • actually based on 8 GA. metal because the chart does not show 5 GA metal. To estimate the service life of 5 GA metal one has to use a logarithmic regression equation to determine the adjustment multiplier for 5 GA metal, which is 4.85. In doing so, the 30 • year life for 18 GA metal is adjusted to 145 years for 5 GA metal. • 0 a 0 0 • 0 0 • 0 • 5. U.S. Army Corps of Engineers, Engineering Manual, EM 1110-2-2909, page 31 6. FHWA publication FLP-91-006, Durability of Special Coatings for Corrugated Steel Pipe, page 13 7. Caltrans Highway Design Manual, Chapter 850, page 850-20 • 0 • 0 Page 5 of 6 Service Life - Inspections Assure Public Safety Structures with large spans, most notably bridges, regardless of the material they are constructed of, are inspected every five years to ensure public safety. It is recommended that starting with the twentieth (20th) year the underground retention basin is in service that it be inspected every fifth (5th) year by a structural engineer to ensure that it is structurally sound. If the engineer finds something suspicious he/she can recommend more frequent monitoring to resolve their concern, and of course, second opinions should be allowed, and perhaps even sought. Page 6 of 6 a This Army Corps publication contains 87 pages. In the interest of brevity, only the relevant pages are included in this submittal. However, the entire document is included on the CD attached to the submittal if there is a desire to peruse the other pages in this document. DEPARTMENT OF THE ARMY EM 1110-2-2902 U.S. Army Corps of Engineers CECW-ED Washington, DC 20314-1000 Manual No. 1110-2-2902 31 October 1997 Engineering and Design CONDUITS, CULVERTS, AND PIPES 1. Purpose. This manual provides (a) guidance on the design and construction of conduits, culverts, and pipes, and (b) design procedures for trench/embankment earth loadings, highway loadings, railroad loadings, surface concentrated loadings, and internal/extemal fluid pressures. 2. Applicability. This manual applies to all USACE commands having civil works responsibilities. 3. General. Reinforced concrete conduits and pipes are used for dams, urban levees, and other levees where public safety is at risk or substantial property damage could occur. Corrugated metal pipes are acceptable through agricultural levees where conduits are 900-mm (36-in.) diameter and where levee embankments are not higher than 4 m (12 R) above the conduit invert. Inlet structures, intake towers, gate wells, and outlet structures should be concrete, or corrugated metal structures may be used in agricultural and rural levees. Life cycle cost studies are required where corrugated metal pipes are used. 4. Distribution. This manual is approved for public release; distribution is unlimited. FOR THE COMMANDER: ��" p'�� J��•yam OTIS WILLIAMS Colonel, Corps of Engineers Chief of Staff This manual supersedes EM 1110-2-2902 dated 30 November 1978. 0,5 4 k m y caPps EM 1110-2-2902 31 Oct 97 aD.L¢1...+O.L_...:f........'�+i........ ... ?....__.......�._�.__—.--..1...—.___ .--._- r.._....._..._ ....... ..... ..;.............. T ----- -. -. -. .._.._...- ...... ... �. ...... .... _:... clq ........ ..... ........... -.'- r r n _..,......_.—...,..................,.............. ..._� .... . Q.... y._.._....._....._.... .. ....... .._.._.....___._ ;...... ............ _............. ...1_""".-.- .. - _._y._.._......_..._.. _ i ....... _..._ •> N ._ .. .. t N O 0 bq '\ Y O N M G>> E .._ N = '- ........i ............. ..... [...... _ N 6 L �cG l0 O w ....._:___...._......_ ..__._.... ..........:.. a.._ ._.5.,__._ ... ..._ L W N O = ..i..�.._........ NO C E ._......j.__............;.. .{...._...._.__l._... __ W .•. _ E N�,. -... #-- ' o R a i �NNNy 2-----:=:5:--:=::: E o 4 Wrye E _i::::::::::::::::a:: mO _ ZS NU _...'..-_.oi _....... g _.!.._.____..}.._..._..- _ ....: !rl n tom.. t p t _ L U O .--...._ : a E.s ,....... : .....— c w c:i C9¢t�1t-E i f f t�l th UOI;eJO}Jad of SJeGk i 4-2 This FHWA publication contains 67 pages. In the interest of brevity, only the relevant pages are included in this submittal. However, the entire document is included on the CD attached to the submittal if there is a desire to peruse the other pages in this document. R 0 �iiOA -FLU-91-006 O. S, —_— a r JJ � U' O Q � Zn� N Z O Z l w Q h W = w Z O G auiv: J O Z F- Z Z ar wF 0 O G J J O N O O cs P Y m o� o O o N Z rv00 m mo aIn a > r- i-- Y4w as J E N C Y U c u N ` i63A7M 1331S 3DV0 Bl-NOUV603d3d O1 Si.'V3A 13 I W, 11 n 0 0 FHWA- FL P-91-1�)Q6 n o r� o a .r c r s m o o .o iS a 2hi � 2 CW U> 2 rT1 \ e Q \ \ O t p \\ Wh m g 2 V om \ * YVN Y (v N Z V y U y V 1 �l lil O p Q I I V r j I r * 6 1 ON 133HS 13315 03ZiW n1d0 NClH1 'NI Z90 0 SZN3a-3211 3�VaAAV 14 I H n HIGHWAY DESIGN MANUAL CHAPTER 850 PHYSICAL STANDARDS Topic 851 - General Index 851.1 - Introduction This section deals with the selection of drainage facility material size and type(s). 851.2 Selection of Material and Type The choice of drainage facility material size and type is based on the following factors: (1) Physical and Structural Factors. Of the many physical and structural considerations, some of the most important are: (a) Durability. (b) Headroom. (c) Earth Loads. (d) Bedding Conditions. (e) Conduit Rigidity. (f) Impact. (g) Watertightness. (2) Hydraulic Factors. Hydraulic considerations involve: (a) Design Discharge. (b) Shape, slope and cross sectional area of channel. (c) Velocity of approach. (d) Outlet velocity. (e) Total available head. (f) Bedload. (g) Inlet and outlet conditions. (h) Slope. (i) Smoothness of conduit. 0) Length. Suggested values for Manning's Roughness coefficient (n) for design purposes are given in Table 851.2 for each type of conduit. See Index 864.3 for use of Manning's formula. 850-1 September 1, 2006 (3) Maintenance and Construction Factors. (a) Local experience. (b) Accessibility of site. (c) Construction conditions. (4) Economy. Comparative cost should be weighed on a long-term basis considering the factors given under Index 801.5. Topic 852 - Design Service Life 852.1 Basic Concepts The prediction of design service life of drainage facilities is difficult because of the large number of variables, continuing changes in materials, wide range of environments, and use of various protective coatings. The design service life of a drainage facility is defined as the expected maintenance free service life of each installation. For all metal pipes and arches that. are listed in Table 853.1A, maintenance free service life, with respect to corrosion, abrasion and/or durability, is the number of years from installation until the deterioration reaches the point of perforation at any location on the culvert (See Figure 854.313). For reinforced concrete pipe (RCP), box (RCB) and arch (RCA) culverts, maintenance free service life, with respect to corrosion, abrasion and/or durability, is the number of years from installation until the deterioration reaches the point of exposed reinforcement at any point on the culvert. For non -reinforced concrete pipe culverts (MRCP), maintenance free service life, with respect to corrosion, abrasion and/or durability, is the number of years from installation until the deterioration reaches the point of perforation or major cracking with soil loss at any point on the culvert. For plastic pipe, maintenance free service life, with respect to corrosion, abrasion, and long term structural performance, is the number of years from installation until the deterioration reaches the point of perforation at any location on the culvert or until the pipe material has lost structural load carrying capacity. This Caltrans publication contains 42 pages. In the interest of brevity, only the relevant pages are included in this submittal. However, the entire document is included on the CD attached to the submittal if there is a desire to peruse the other pages in this document. 1(, 850-2 May 1, 2001 HIGHWAY DESIGN MANUAL Table 851.2 Manning N-Value for Alternative Pipe Materials() Type of Recommended N-Value Conduit Design Value Range Corrugated Metal Pipe (2) (Annular and Helical) (3) 68 mm x 13 nun corrugation 0.025 0.022 - 0.027 76 mm x 25 mm 0.028 0.027 - 0.028 125 mm x 25 ram 0,026 0.025 - 0.026 152 mm x 51 mm 0.035 0.033 - 0,035 229 mm x 64 mm 0.035 0.033 - 0.037 Concrete Pipe Precast 0,012 0.011 - 0.017 Cast -in -place 0.013 U12-0,017 Concrete Box 0.013 0.012 - 0.018 Plastic Pipe Smooth interior 0.012 0.010 - 0.013 Corrugated Interior 0.022 0.020 - 0.025 Spiral Rib Metal Pipe 19min (W)x25mm(D)@292nun o/c 0.013 0.011-0.015 19mm(W)x19mm(D)@191mmo/c 0.013 0.012-0.015 19 mm (W) x 25 mm (D) @ 213 mm o/c 0.013 U12-0.015 Composite Steel Spiral Rib Pipe 0.012 0.011 -0.015 Steel Pipe, Ungalvanized 0.015 - Cast Iron Pipe 0.015 - Clay Sewer Pipe 0.013 - (I) Tabulated n-values apply to circular pipes flowing full. For noncircular or partially Cult conduits the tabulated values maybe modified as shown in Appendix B of HDS No. 5, Hydraulic lksicn of Highway Culvers. (2) For lined corugated metal pipe, a composite roughness coefficient maybe computed using the procedures outlined in the IMS No. 5, Hydraulic Design of IlighM Culverts. (3) Lower n-values may be possible fur helical pipe under specific flow conditions (refer to FII WA's publication Hvdrautic Flow Resistance Factors for Corrugated Metal Conduitsl, but in general, it is recommended that (be tabulated n-value be used for both annular and helical corrugated pipes. 850-4 September 1, 2006 HIGHWAY DESIGN MANUAL Table 853.1A Allowable Alternative Materials Type of Service Installation Life Allowable Alternatives (yrs)t Joint Type Standard Positive :Downdrain Culverts & Drainage 50 ASSRP, ASRP, CAP, CASP, CSSRP, X X Systems CIPCP, CSP, NRCP, SAPP, SSPP, SSRP, RCP, RCB, PPC Overside Drains 50 CAP, CASP, CSP, PPC X Underdrains 50 PAP, PSP, PIPET, PPVCP X Arches (Culverts & 50 ACSPA, CAPA, CSPA, RCA, SAPPA, X X Drainage Systems) SSPPA, SSPA LEGEND ACSP - Aluminized Corrugated Steel Pipe Arch PPVCP - Perforated Polyvinyl Chloride Pipe A ASSRP - Aluminized Steel Spiral Rib Pipe PSP - Perforated Steel Pipe ASRP - Aluminum Spiral Rib Pipe RCA - Reinforced Concrete Arch CAP - Corrugated Aluminum Pipe RCB - Reinforced Concrete Box CAPA - Corrugated Aluminum Pipe Arch RCP - Reinforced Concrete Pipe CSSRP - Composite Steel Spiral Rib Pipe SAPP - Structural Aluminum Plate Pipe CASP - Corrugated Aluminized Steel Pipe, Type 2 SAPPA - Structural Aluminum Plate: Pipe Arch CIPCP - Cast -in -Place Concrete Pipe SSPA - Structural Steel Plate Arch CSP - Corrugated Steel Pipe SSPP - Structural Steel Plate Pipe CSPA - Corrugated Steel Pipe Arch SSPPA Structural Steel Plate Pipe Arch NRCP - Non -Reinforced Concrete Pipe SSRP - Steel Spiral Rib Pipe PAP - Perforated Aluminum Pipe X - Permissible Joint Type for the Type PPC - Plastic Pipe Culvert of installation Indicated PPET - Perforated Polyethylene Tubing NOTE: 1. The design service life indicated for the various types of installations listed in the table may be reduced to 25 years in certain situations. Refer to Index 852.1 for a discussion of service life requirements. HIGHWAY DESIGN MANUAL All types of culverts are subject to deterioration from corrosion, or abrasion, or material degradation. Corrosion may result from active elements in the soil, water and/or atmosphere. Abrasion is a result of mechanical wear and depends upon the frequency, duration and velocity of flow, and the amount and character of bedload. Material degradation may result from material quality, UV exposure, or long term material structural performance. To assure that the maintenance free service life is achieved, alternative metal pipe may require added thickness and/or protective coatings. Concrete pipe may require extra thickness of concrete cover over the steel reinforcement, high density concrete, using mineral admixtures, epoxy coated reinforcing steel, and/or protective coatings. Means for estimating the maintenance free service life of pipe, and techniques for extending the useful life of pipe materials are discussed in more detail in Topic 854. The design service life for drainage facilities for all projects should be as follows: (1) Culverts, Drainage Systems, and Side Drains. (a) Roadbed widths greater than 28 feet - 50 years. (b) Greater than 10 feet of cover - 50 years. (c) Roadbed widths 28 feet or less and with less than 10 feet of cover - 25 years. (d) Installations under interim alignment - 25 years. (2) Overside Drains. (a) Buried more than 3 feet- 50 years. (b) All other conditions, such as on the surface of fill slopes - 25 years. (3) Subsurface Drains. (a) Underdrains within roadbed - 50 years. (b) Underdrains outside of roadbed - 25 years. (c) Stabilization trench drains - 50 years. 850-3 September 1, 2006 In case of conflict in the design service life requirements between the above controls, the highest design service life is required except for those cases of interim alignment with more than 10 feet of rover. For temporary construction, a lesser design service life than that shown above is acceptable. Where the above indicates a minimum design service life of 25 years, 50 years may be used. For example an anticipated change in traffic conditions or when the highway is considered to be on permanent alignment may warrant the higher design service life. Topic 853 - Alternate Materials 853.1 Basic Policy When two or more materials meet the design service life, and structural and hydraulic requirements, the plans and specifications must provide for alternative pipes, pipe arches, overside drains, and underdrains to allow for optional selection by the contractor. (1) Allowable Alternatives. A table of allowable alternative materials for culverts, drainage systems, overside drains, and subsurface drains is included as Table 853.1A. This table also identifies the various joint types described in Index 853.1(2) that should be used for the different types of installations. (2) Joint Requirements. The Standard Specifications set forth general performance requirements for transverse field joints in all types of culvert and drainage pipe used for highway construction, such as corrugated metal pipe, and reinforced and plain concrete pipe. Table 853.1A indicates the alternative types of joints that are available for different arch and pipe installations. The two joint types specified for culvert and drainage systems are identified as "standard" and "positive". 850-14 September I, 2006 HIGHWAY DESIGN MANUAL Table 854.2 Cast -in -Place Concrete Pipe Fill Height Table Concrete Strength (psi) 3,500 4,000 4,500 5,000 Diameter. Maximum Fill Height (in) (ft) 30 13 13 14 15 36 12 13 14 15 42 11 12 13 14 48 13 14 15 16 54 13 14 15 16 60 12 13 14 15 66 12 13 14 15 72 11 12 13 14 78 11 12 13 14 84 11 12 13 14 The following measures are commonly used to prolong the maintenance free service life of steel culverts: (a) Galvanizing. Under most conditions plain galvanizing of steel pipe is all that is needed; however, the presence of corrosive or abrasive elements may require additional protection. • Protective Coatings - The necessity for any coating should be determined considering hydraulic conditions, local experience, possible environmental impacts, and long-term economy. Approved protective coatings are bituminous asphalt, which is hot -dipped to cover the entire inside and outside of the pipe; asphalt mastic and polymeric sheet, which can be applied to the inside and/or outside of the pipe; and polymerized asphalt, which is hot - dipped to cover the bottom 90' of the inside and outside of the pipe. All of these protective coatings are typically shop -applied prior to delivery to the construction site. A polymeric sheet coating provides much improved corrosion resistance over bituminous coatings and can be considered to typically allow achievement of a 50- year maintenance free service life without need to increase thickness of the steel pipe. To ensure that a damaged coating does not lead to premature catastrophic failure, the base steel thickness for pipes that are to be coated with a polymeric sheet must be able to provide a minimum 10-year service life prior to application of the polymeric material. In addition, a bituminous lining or bituminous paving can be applied over a bituminous coating primer on the inside: of the pipe for extra corrosion or abrasion protection (see Standard Specification 66-1.03, paragraphs 4 and 5). Citing Section 5650 of the Fish and Game Code, the Department of Fish and Game (DFG) may restrict the use of bituminous coatings on the interior of pipes if they are to be placed in streams which flow continuously or for an extended period (more than 1 to 2 days) after a rainfall event. Their concern is that abraded particles of asphalt could enter the stream and degrade the fish habitat. Where abrasion is unlikely, DFG concerns should be minimal. DFG has indicated that they have no concerns regarding interior application of polymerized asphalt or polymeric sheet coatings, even under abrasive conditions. Where the materials report indicates that soil :side corrosion is expected, a bituminous asphalt coating (i.e., hot - dipped) or an exterior application of polymeric sheet, as provided in the Standard Specifications, combined with galvanizing of steel, is usually effective in HIGHWAY DESIGN MANUAL forestalling accelerated corrosion on the backfill side of the pipe. Where soil side corrosion is the only concern, exterior bituminous asphalt protection (i.e., hot - dipped) may provide up to 25 years and a polymeric sheet coating may provide up to 50 years of additional service life. For locations where water side corrosion and/or abrasion is of concern, protective coatings, or protective coatings with pavings, or protective coatings with linings, in combination with galvanizing will add to the culvert service life to a variable degree, depending upon site conditions and type of coating selected. In addition, composite steel spiral ribbed pipe which is a steel spiral ribbed pipe externally precoated with a polymeric sheet, and internally polyethylene lined, may also provide additional service life. If hydraulic conditions at the culvert site require a lining on the inside of the pipe or a coating different than that indicated in the Standard Specifications, then the different requirements must be described in the Special Provisions. • Extra Metal Thickness. Added service life can be achieved by adding metal thickness. However, this should only be considered after protective coatings and pavings have been considered. Since 0.052 inch thick steel culverts is the minimum steel pipe Caltrans allows, it must be limited to locations that are nonabrasive. Table 854.3A constitutes a guide for estimating the added service life that can be achieved by coatings and invert paving of steel pipes based upon abrasion resistance characteristics. However, the table does not quantify added service life of coatings and paving of steel pipe based upon corrosion protection. Recently developed coating products, like polymerized asphalt and polymeric sheet, can provide superior abrasive resistant qualities (as much as 10 or more times that of bituminous coatings of similar thickness). In heavily abrasive situations, concrete inverts should be 850-15 September 1, 2006 considered. The guide values for years of added service life should be modified where field observations of existing installations show that other values are more accurate. The designer should be aware of the following limitations when using Table 854.3A: • Channel Materials: If there is no existing culvert, it may be assumed that the channel is potentially abrasive to culvert if sand and/or rocks are present. Presence of silt, clay or heavy vegetation may indicate a non-abrasive flow. • Flow velocities: For continuous and substantial flow, the years of invert protection can be expected to be one- half of that shown. For the more typical intermittent flow, the velocities indicated in the table should be compared to those generated by the 2-5 year return frequency flood. (b) Aluminized Steel (Type 2). Evaluations of aluminized steel (type 2) pipe in place for over 40 years have provided data that substantiate a design service life with respect to corrosion resistance equivalent to aluminum pipe. Therefore, for pH values between 5.5 and 8.5, and minimum resistivity values in excess of 1500 ohm -cm, 0.064 inch aluminized steel (type 2) is considered to provide a 50 year design service life. Where abrasion is of concern, aluminized steel (type 2) is considered to be roughly equivalent to galvanized steel. Bituminous coatings are not recommended for corrosion protection, but may be used in accordance with Table 854.3A for abrasion resistance. For pH ranges outside the 5.5 and 8.5 limits or minimum resistivity values below 1500 ohm -cm, aluminized steel (type 2) should not be used. In no case should the thickness of aluminized steel (type 2) be less than the minimum structural requirements for a given diameter of galvanized steel. Figure 854.313 should be used to determine the minimum thickness and limitation on the use of corrugated steel and spiral rib pipe for various 100,000 50,000 20,000 2 V 10,000 x O cc 5,000 i F j 3,000 1A H H 2,000 W 1,500 1,000 _Z 500 - 200 3 HIGHWAY DESIGN MANUAL Figure 854.3E Minimum Thickness of Metal Pipe for 50 Year Maintenance Free Service Life (2) 12 ga. tlegs. -- 10 ga. ) - � - 8 ga. -- .- .. - ---- --- -- _A-- -- 1 1---Prote ctiv Coatin Required 16 ga. 14 ga. ) ( 12 ga. ----------'-- - ----------- - I--� Galvanized Steel -Metal thickness as indicated 16 ga.Aluminum or 16 ga.Aluminized Steel (Type 2) Acceptable 10 ga. ( ( 8 ga. protective Coating., Re uired 1 850-19 September 1, 2006 4 5 5.5 6 7 7.3 8 8.5 , 9 10 pH Notes: 1. For pH and minimum resistivity levels not shown refer to Fig. 854.3C steel pipes. (California Test 643) 2. Service life estimate are for various corrosive conditions only. 3. Refer to Index 854.3(2) and 854.4(2) for appropriate selection of metal thickness and protection coating to achieve service life requirements. 850-22 July I, 2004 HIGHWAY DESIGN MANUAL available in the thickness as indicated on Tables 854.4D & E. • Height of Fill - The allowable overfill heights for corrugated aluminum pipe and pipe arches for various diameters and metal thickness are shown on Tables 854.4A, B & C. For aluminum spiral rib pipe, overfill heights are shown on Tables 854.4D, & E. To properly use the above mentioned tables, the designer should be aware of the basic premises on which the tables are based as well as their limitations. (See Index 854.3(2)). (4) Shapes. Corrugated aluminum pipe, aluminum spiral rib pipe and pipe arches are available in the diameters and arch shapes as indicated on the maximum height of cover tables. Helical corrugated pipe must be specified if anticipated heights of cover exceed the tabulated values for annular corrugated pipe. For larger diameters, arch spans or special shapes, see Index 854.6. Non-standard pipe diameters and arch sizes are also available. (5) Invert Protection. Invert protection of corrugated aluminum is not recommended. (6) Spiral Rib Aluminum. Aluminum spiral rib pipe is similar to spiral rib steel. Figure 854.313 should be used to determine the limitations on the use of spiral rib aluminum pipe for the various levels of pH and minimum resistivity. Tables 854.4D & E give the maximum overfill for aluminum spiral rib pipe constructed under the acceptable methods contained in the Standard Specifications and the essentials discussed in Index 829.2. 854.5 Special Purpose Types (1) Smooth Steel. Smooth steel (welded) pipe can be utilized for drainage facilities under conditions where corrugated metal or concrete pipe will not meet the structural or design service life requirements. (2) Composite Steel Spiral Rib Pipe. Composite steel spiral rib pipe is a smooth interior pipe with efficient hydraulic characteristics. See Table 851.2. Composite steel spiral rib pipe with its interior polyethylene liner exhibits good abrasion resistance and also resists corrosion from chemicals found in a typical stolmdrain or sanitary sewer environment. The exterior of the pipe is protected with a polyethylene film which offers resistance to corrosive backfills. The pipe will meet a 50 year maintenance free service life under most conditions. (3) Proprietary Pipe. See Indexes I10.10 and 601.5(3) for further discussion and guidelines on the use of proprietary items. 854.6 Structural Metal Plate (1) Pipe and Arches. Structural plate pipes and arches are available in steel and aluminum for the diameters and thickness as shown on Tables 854.6A, B, C & D. (2) Strength Requirements. (a) Design Standards. • Corrugation Profiles - Structural plate pipe and arches are available in a 6" x 2" corrugation for steel and a 9" x 2'h" corrugation profile for aluminum. • Metal Thickness - structural plate pipe and pipe arches are available in thickness as indicated on Tables 854.6A, B, C & D. • Height of Fill - The allowable height of cover over structural plate pipe and pipe arches for the available diameters and thickness are shown on Tables 854.6A, B,C&D. Where it maximum overfill is not listed on these tables, the pipe or arch size is not normally available in that thickness. HIGHWAY DESIGN MANUAL Table 854.6A Structural Steel Plate Pipe 6" x 2" Corrugations MAXIMUM HEIGHT OF COVER (ft) Diameter Metal Thickness (in) (in) 850-35 September 1, 2006 0.109 0.138 0.168 0.218 0.249 0.280 (12 ga.) (10 ga.) (8 ga.) (5 ga.) (3 ga.) (1 ga.) 60 55 81 105 137 159 178 66 50 74 96 125 145 162 72 46 68 88 114 133 149 77 42 62 81 106 122 137 84 39 58 76 99 113 127 90 36 54 71 92 105 119 96 35 51 66 87 99 112 102 32 48 62 81 93 105 108 30 45 59 77 88 99 114 29 43 56 73 83 94 120 27 40 53 69 79 89 126 26 38 50 66 75 85 132 25 37 48 63 72 81 138 24 35 46 60 69 77 144 23 34 44 58 66 74 150 22 32 42 55 63 71 156 21 31 40 53 61 68 162 20 30 39 51 58 66 168 19 29 38 49 56 64 174 19 28 36 48 54 61 180 18 27 35 46 52 59 I 186 17 26 34 44 51 57 1 192 -- 25 33 43 49 56 198 24 32 42 48 54 204 1 24 31 40 46 52 210 23 30 39 45 51 1 216 -- 29 38 44 49 222 28 37 42 48 1 228 28 36 41 47 234 27 35 40 45 240 -- 34 39 44 246 33 38 43 252 33 37 42 NOTE: (1) When flow velocities exceeds 5 fl/s under abrasive conditions thicker metal may be required. i 550-20 September 1, 2006 C 0 0 0 a 0 0 HIGHWAY DESIGN MANUAL Figure 854.3C Chart for Estimating Years to Perforation of Steel Culverts YEARS TO PERFORATION - 18 GAGE STEEL CULVERT ct • • • • 31 • • • • 55 > z • In 0 �® �� b, ----------------- This Los Angeles County publication contains 149 pages. In the interest of brevity, only the relevant pages are included in this submittal. However, the entire document is included on the CD attached to the submittal if there is a desire to peruse the other pages in this document. Development Planning for Storm Water Management September 2002 A Manual for the Standard Urban Storm Water Mitigation Plan (SUSMP) Los Angeles County Department of Public Works 4 y PUBLIC WOPKS L Qy-5801 a 2b l APPENDIX B BMP DESIGN CRITERIA B.6 EXTENDED/DRY DETENTION BASINS OR UNDERGROUND DETENTION TANKS DESCRIPTION Extended/dry detention basins are depressed basins that temporarily store a portion of stormwater runoff following a storm event. Underground detention tanks function similar to detention basins. However, since underground detention tanks are located below ground, the surface above these systems can be utilized for other more useful needs (parking lots, sidewalks, landscaping adjacent to buildings, etc). Water is controlled by means of a hydraulic control structure (orifice and/or weirs) to restrict outlet discharge. The extended/dry detention basins and underground detention tanks normally do not have a permanent water pool between storm events. The objectives of both systems are to remove particulate pollutants and to reduce maximum runoff values associated with development to their pre -development levels. Detention basin facilities may be berm - encased areas or excavated basins. Detention tank facilities may be corrugated metal pipe, concrete pipe, or vaults. ADVANTAGES 1. Modest removal efficiencies for the larger particulate fraction of pollutants. 2. Removal of sediment and buoyant materials. Nutrients, heavy metals, toxic materials, and oxygen -demanding particles are also removed with sediment substances associated with the particles. 3. Can be designed for combined flood control and stormwater quality control. 4. Requires less capital cost and land area when compared to wet pond BMP. 5. Downstream channel protection when properly designed and maintained. LIMITATIONS 1. Require sufficient area and hydraulic head to function properly. 2. Generally not effective in removing dissolved and finer particulate size pollutants from stormwater. 3. Some constraints other than the existing topography include, but are not limited to, the location of existing and proposed utilities, depth to bedrock, location and number of existing trees, and wetlands. 4. Extended/dry detention basins have moderate to high maintenance requirements. 5. Sediments can be resuspended if allowed to accumulate over time and escape through the hydraulic control to downstream channels and streams. 6. Some environmental concerns with using extended/dry detention basins, include potential impact on wetlands, wildlife habitat, aquatic biota, and downstream water quality. 7. May create mosquito breeding conditions and other nuisances. DESIGN CRITERIA July s. 2000 B-25 s SPEED Civil CONSULTING ENGINEERS fle. pIny you create Me eanrmunity asset you enosion October 2, 2006 Timothy R. Jonasson, Public Work Director/City Engineer LA QUINTA PUBLIC WORKS DEPARTMENT 78-495 Calle Tampico La Quinta, CA 92253 Dear Mr. Jonasson: Underground Storm Water Retention Chamber — Galvanized Metal Plate Arch Washington Park, PM 30903 My guess is --- it's equally puzzling for you, as it is for me, regarding how our view points of galvanized metal products have parted to polar opposites. First let me say I do not believe I have sold -out simply because I'm paid to represent my client. To the contrary, our view points may not have been fully aligned as I neared retirement last fall. Not because I disagreed with your perspective then, but most likely because the differences, if there were any, were unspoken or unknown to each other regarding the respective view points that we each consider to be the critical aspects of designing an underground retention facility. For me, the critical aspect of designing an underground retention basin is duplicating the basic elements of surface retention basin design in an underground facility. Doing so means developing a facility geometry that includes an open bottom design and relatively easy access to the chamber for cleaning and inspection. The type of material used to accomplish that end was not critically important in my opinion, primarily because I believe the choice of materials is a function of strength and durability, which in most cases can be resolved with proper application of the material. One of the key reasons I choose to forego the Cabazon visit last year was the fact I considered that facility to be the wrong application for La Quinta and a waste of tirne to consider it (call me close minded here). The Cabazon facility is a "detention" facility not a "retention" facility. As a retention facility it does not possess what I consider to be the critical design aspect --- it does not possess an open bottom. As a result, the percolation surface is inaccessible for cleaning and will silt up rendering the facility useless long before the structural service life of the facility is met. 50855 WASHINGTON ST ♦ SUITE C-280 ♦ LA QUINTA ♦ CALIFORNIA 92253 Office: 760.285,7335 Fax 760.269.3580 w .speercivil.net Timothy Jonasson October 2, 006 Page 2 of 5 However, based on your comments, and comments of engineering staff, your joint assessment of the Cabazon facility as a poor example for duplication in La Quinta is more material based than geometry based, which explains the basis for my earlier statement that our view points were not fully aligned last fall. I did not know that you considered the Cabazon facility to be a bad example for retention basin design because of its material. The Washinaton Park Proposal The good news is my client concurs with the open bottom, easy access, design concept for underground retention facilities. However, the challenging aspect of his proposed facility is the choice of material. He has chosen galvanized metal. In our ongoing discussions since early June, I believe his proposal has been judged by a biased jury. I don't mean that in a critical way. We all have biases, because all of us have experienced different things in life, and in our professional careers, and those experiences provide the basis for our decision making. Given that candid premise, biased juries can make sound decisions --- when they understand where the bias is entering the decision making process. If I had known that you considered galvanized metal a non -starter because of your experience at Cabazon and Ed's experience in Newport Beach I would have provided a more distinct and clearer difference in the documentation I originally supplied, between those examples which are the reference basis for your decision making, and the product that is proposed for Washington Park. Unraveling the Bias The most fundamental aspect in using galvanized metal and obtaining a longer service life is found in the thickness of the metal used in the facility. A thicker metal with a thicker coating of galvanizing material (zinc) equates to a longer service life. There are other factors that also impact service life, and I'll address that a bit later, but the key aspect to unraveling the bias is found in the metal thickness. I suspect your experience with galvanized metal has been with relatively small diameter corrugated metal pipe (ie 48" diameter or smaller). Small diameter pipe is typically fabricated of 16 gauge metal because a thicker gauge is not needed to fulfill the structural needs for the intended application. However, 16 gauge metal has a much thinner galvanized coating and therefore does not provide the long service life that reinforced concrete pipe provides, thus it is easy to see how and why one would start to insist concrete is a better material than galvanized metal. But that comparison, and its antidotal conclusion, does not give galvanized metal a fair hearing. Just as there is a design science associated with using concrete, there is a design science associated with using galvanized metal. If achieving a long service life is a critical design aspect for a given facility, and galvanized metal is the material of choice, it can be achieved by properly applying that design science. If a designer does 50855 WASHINGTON SI♦ SUITE C-280 ♦ LA QUINTA • CALIFORNIA 92253 Office : 760.285.7335 Fax 760.269.3580 w .speercivil.net Timothy Jonasson October 2, 006 Page 3 of 5 not apply the design sciences of the respective materials in the design process, facility failure is a realistic possibility. In fact, there's a strong argument that designing facilities with these materials without applying the related design sciences could be considered non-professional practice. Mainstream Engineering Practice What I did not know in June (nor most likely did your staff) but I now understand as a result of hours of research regarding this material is: A very good, if not the best, source for design guidance regarding the use of galvanized metal products is Chapter 850 in Caltrans' Highway Design Manual. 2. The leading, public sector, authorities in the public works field: the Federal Highway Administration (FHWA), the US Army Corps, and Caltrans all consider galvanized metal to be a useful material in building publicly financed facilities. Using galvanized metal products is clearly in the mainstream of engineering practice. Galvanized metal is not an inferior product unless it is applied in a non-professional way ignoring the science that supports its use. Similar Facilities Galvanized metal products are widely used for underground "detention" basins throughout the country. But there isn't a lot of existing "retention" basins to cite as examples because storm water retention is not a widely employed practice outside the Coachella Valley and the Phoenix area. Nevertheless, certain aspects of the two types of facilities can be compared. They both fill up with storm water during the storm event, then percolate or release the water over a period of time. As a result, it's reasonable to compare the "water" side of the facility for service life longevity. That information was submitted in the original submittal made in June. The use of detention basins elsewhere in the United States is a result of NPDES regulations. Detention basins are a standard BMP facility for use in improving storm water quality. Starting at the EPA website and perusing online documents one can find references to the source of information they promulgate. An early document that is widely cited by governing authorities across the nation is a document entitled "Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban BMPs" published in 1987 by the Metropolitan Washington Council of Governments, Washington, DC. I have not seen the document because it's not available online. But it clearly has impacted the design practice across the nation from the DC area to the Pacific Northwest to California. In all locations, galvanized metal is used for underground detention basins. The Parsons Brinkerhoff study that was submitted to the La Quinta Engineering Department in June contained a critical review of several galvanized metal facilities constructed in the DC area. It should be noted that none of the facilities reviewed by Parsons Brinkerhoff were constructed of 5 gauge metal. They 50855 WASHINGTON ST ♦ SUITE C-280 ♦ LA QUINTA ♦ CALIFORNIA 92253 Office: 760.285.7335 Fax 760.269.3580 w .speercivil.net % Timothy Jonasson October 2, 006 Page 4 of 5 were all constructed of much thinner metal. Hence the Washington Park facility will yield a very substantial service life because it is constructed of thicker metal. The FHWA websitel'I has an online manual entitled "Stormwater Best Management Practices in an Ultra -Urban Setting". The text associated with Figure 11 in that manual says: "Detention tanks and vaults are underground structures used to attenuate peak stormwater flows. They are usually constructed out of either concrete or corrugated metal pipe (CMP) and must consider the potential loading from vehicles on the vault or pipe..... Some design j information on CMP systems is available in Design and Construction of Urban Stormwater Management Systems (ASCE, 1992)" Clearly, galvanized metal is a commonly facilities and there are recognized sources consult in preparing their facility design. Design Process used material for underground detention of information for design professionals to It's recommended that the Caltrans design process be adopted for designing galvanized metal facilities in La Quinta. Caltrans is one of the leading research agencies regarding the use of galvanized metal. When FHWA wanted to produce a document regarding the use of galvanized metal they turned to the US Army Corps which in turn relied on Caltrans documentation in their preparation of the FHWA document. That twin showing of confidence in Caltrans' information on this topic by the leading authorities in public works design in the United States is hard to ignore. Additionally, the Highway Design ® manual cited earlier in this letter was published just last month (Sept 1, 2006), therefore, it quite likely contains the latest and most authoritative guidance available in using r galvanized metal. N The Proposed Facility The underground retention facility proposed for Washington Park will employ an open bottom design utilizing 5 gauge galvanized metal plate arches that are twenty five feet (25') wide at the bottom with a rise of twelve feet six inches (12' 6") from the bottom of the arch to the high point, and set on linear concrete footings. The facility will be constructed under the parking lot near its lowest elevation. We are seeking concept approval at this time. Design details will be addressed in the plan review process. (1) http://www.fhwa.dot.gov/environment/ultraurb/index.htm 50855 WASHINGTON Sr • SUITE C-280♦ LA QUINTA ♦ CALIFORNIA 92253 Offo 760,285,7335 Fax 760.269.3580 w .speercivil.net W Timothy Jonasson October 2, 006 Page 5 of 5 The attached picture, which has been provided in prior submittals, provides a good visual concept of what is proposed, except, the Washington Park facility will not have four "tunnels" like the facility in the picture, it will have just one. Additionally, the Washington Park facility will not have its access opening built into the concrete bulk head, but instead it will occur in the top of the arch near the bulkhead and use the bulkhead for placement of ladder steps. The attached cross-section shows the proposed trapezoidal bottom that will be used subject to verification by a soils engineer the underground embankment can handle the soil pressure imposed by the concrete footing without any subsidence. Conclusion This submittal, along with the two previous submittals regarding this proposal provides significant information regarding the quality and concept of the proposed facility. Nonetheless, if additional information is needed please advise. Sin rely, Steven D. S r Principal Attachments 50855 WASHINGTON ST ♦ SUITE C-280 ♦ LA QUINTA ♦ CALIFORNIA 92253 Office: 760.285,7335 Fax: 760.269.3580 w .speercivil.net 6imanaiona Nominal _....__..._,_ ................._._. _. Waterway Are Lea0h Span, Rue, At" Ri"/Spon Radices ---.....___.__.. _... feet Ft, -In• ft., R." Inches Pi 110 _... 7.9 Coo 41 .__. 27 2-4 100 038 38 30 3-2 1-5 0 0.53 36 36 7A 2.5 12.0 0.34 45 33 210 15.0 4.41 43 36 .. 3.8 20,0 0,52 42 d2.. 8.0 2.11 17.0 G.36 51 39 34 20.0 0 42 49 42 4 2 26.6 0.52 48 48 90 2.1.1 19.0 10.33 a9 42 111 26Z 0,43 .55 48. d-II .. 33.6 0.52 54 34 10.0 36 25.0 0.35 b4 48 4.5 34,0 0.44 ry, 54 5-3 410 0.52 hQ 60 f 1 O 3.6 278 0 32: 73 51 4.6 37,0 0 47... 68 7 5�9 do.0 052 66 606. 12.0 a1 3b.0 034 c� 5.0 45-0 0.42 73 63 6.3 59.0 0.52 72 %2 13.0 : 44 38.0 0.32 87 60 54 49.0. 039 81 66 6-9 704 0.52 78 :8 14.0 46 47-0 0.33 91 66 5.7 58,5 0.4Q 86 72 �.... 7-3 80.7 0.62 84 84 150 4-8 500 031. i0! 69 - 58 62.8 0,33 43 75:.. 6-7 75,0 044 4i 61 7.9 92.6 0 52 90 90 i61 53 000 0.:Q 103 75 1.1 96.9 .14 97 87 p,-i t05_C, 0512 96 96 ;LO 5-3 '63.0 0'1 115 78 '. 7-2 - 9240 0,42'. 103 90 8.10 1 19, 0 : 0,52 102 .. : 102 18,0 5-9 75.0 032 119 84 7-8 1C14.6 043 109 96 8 1 1 126.0 0.50 108 105 ,90 a 87f! 033 123 90. 83. 1.1 &0 : 0,43 115 102 9.5 140.7 050 114 111 zt» 64 at 0 0.32 133 93 813 124.0 0.42 122 105 104 156.0 0.50 120 i 17 r 21.0 6-11 104.E 0.33 137 99 840 139.0. 0,42 128 III 1¢6 172.0 0.50 126 173 22.0 6.11 109.0 0.32 146 W2 8-11 146.0 0.40 135 114 111) 190.0 0.50 132 129 213,0 2U 134.0 COS W III . ' 9-10 171.0 0,43 140 123. 11.6 206.0 0.50 138 139 24.0 86 149.0 0.36 152 117 104 188.0 0.43 146 129 ' 120 226.6 0.50 144 141 .0 Oil F a 155.0 0.34 r ,4 '60 i20 i 2t 246.0 ..pan . R R Nosh 50 Figure S. Arch 0-""S.00s ore io "t'de crash of couugahons are ore subiacs to n•unufacturing tolaronces. ,o +5etarndne proper gage, use Tabiet 255 and 26 and design nfarmotfon found on Pages 17 21 For addittomd orch rues, tee your CONTECH Soles Engineer. W is CORROSION ENGINEERING Corrosion Engineering is a specialized field, or branch, of engineering. Until 1999, the State of California issued professional engineering licenses in "Corrosion Engineering". Although the state discontinued licensing that branch of professional engineering, the need for Corrosion Engineering, and Corrosion Specialists, did not disappear. In fact, the state regulations' enforced by the State Water Resource Control Board require Corrosion Specialists to be involved in the design of Underground Storage Tanks (UST's). The UST regulations DO NOT apply to the proposed underground retention basin, as their intent is to regulate hazard substances stored in underground tanks with regard to preventing leakage into the ground water. As of this writing, storm water directed to retention basins in La Quinta is not considered a hazard substance. The reason for including this section on Corrosion Engineering in the submittal packet is to call attention to the fact this is a specialized field and judgments rendered regarding corrosion of underground structures and their long term durability should be made by appropriately credentialed professionals. For example, the State Water Resource Control Board requires the following credentialingz: 1. accreditation or certification by NACE International (National Association of Corrosion Engineers) as either Corrosion Specialist or Cathodic Protection Specialist. The attached table highlights the areas of training and work experience required to become certified. 2. a state registered professional Corrosion Engineer. No other training or certification is required. 3. state registration as a professional engineer other than a registered Corrosion Engineer with additional certification or licensing that includes education and experience in corrosion control of buried or submerged metal piping systems and tanks. This additional certification or licensing can be achieved by obtaining NACE's Corrosion Specialist or Cathodic Protection Specialist certification. 4. state registration as a professional engineer other than a registered Corrosion Engineer with additional certification or licensing that is equivalent to NACE's Corrosion Specialist or Cathodic Protection Specialist certification. CORRPRO COMPANIES, INC. Corrpro Companies is a nationally recognized firm in the corrosion engineering field. They were retained by the National Corrugated Steel Pipe Association to prepare a Condition and Corrosion Survey. The following page summarizes their findings, and immediately follow the summary page is the entire report. 1 Section 2635, Chapter 16, Division 3, Title 23 of the California Code of Regulations. 2 http://www.swrcb.ca.gov/ust/leak_prevention/Igs/145_2.htmi Summary of Condition and Corrosion Survey 1. This surrey focused on thin gauge galvanized corrugated steel pipe only. It should be noted that there have been many studies by conducted by public and private organizations. Some organizations have included the thicker gauge material in their studies. More on that latter aspect can be found in other sections of this submittal packet. 2. The "report concentrates exclusively on the ability to analyze or to predict the time to pipe failure due to exterior corrosion on plain galvanized corrugated steel storm sewer and culvert pipe." (page 2) 3. Pursuant to the goal of achieving a method for predicting facility service life the study sampled soils at the sites where the age and condition of the facility was known and then established a correlation between the soil and the service life. 4. Graphs 7 & 8 on pages 32 and 33 show the 'Predicted Age to Plain Galvanized Corrugated Pipe Failure...." 284 out of the 340 soil samples predicted a service life of the associated structure to be in excess of 100 years. Condition and Corrosion Survey on Corrugated Steel Storm Sewer and Culvert Pipe Final Report March 1991 Prepared for the National Corrugated Steel Pipe Association in cooperation with the American Iron and Steel Institute by Corrpro Companies, Inc. CONDITION AND CORROSION SURVEY Corr f ro SOIL SIDE DURABILITY Corrpro Corin,uenie8. titc. OF CORRUGATED STEEL PIPE P.O.1179 °° ° Medina, OH 44258 (216) 723-5082 Fax (216) 722-7654 Telex 887227 Anchorage Final Report P.O. Box 91929 AK Anchorage, AK 99509 (907) 561-am March, 1991 Attends P.O. Drawer 360516 Decatur, GA 30g36-0516 (404) 593-9593 by: Bekeragsld 5630 District Blvd. CORRPRO COMPANIES, INC. Suite 102 Bakersfield, CA 93313 PROJECT CORROSION AND DATA ANALYSIS ENGINEER (805) 397-6682 Mr. James B. Bushman, P.E. 931 ` West Albion Vice President of Technical Services and Development Schaumburg, IL 60193 Corrpro Companies, Inc. (708) 980-8770 Denver PROJECT FIELD ENGINEERING MANAGER Unit B Tucson Way Mr. Corwin L. Tracy, P.E. Englewood, CAlw„z (3g3) 799-6631 Chief Engineer National Corrugated Steel Pipe Association Houston P.O..Box 100 Spring, TX 7738;I PROJECT STATISTICAL ANALYSIS (713) 350-0205 Los Angeles Mr. Warren R Rogers, Ph.D. 4572 Telephone Road President Suite 921 Warren Rogers Associates, Inc. (Ventura, CA 93003 (cgs) 650-1 zse NewPROJECT COMPUTER DATA BASE MANAGER P.O. Box o p29 Ms. Julie R. Gaeckle Kenner, LA 70D63 Corrpro Companies, Inc. (504) 467 7766 New York 197 Route 18, Suite 3000 East Brunswick, NJ 08816 (201) 214-2651 Prepared for the NATIONAL CORRUGATED STEEL PIPE ASSOCIATION PMedea'r 1255 Twenty -Third Street, N.W., Suite 850 610 Brandywine Parkway on, DC 20037-1174 well chaster, PA 1e3e0 Washington, (215)344-7002 Telephone: (202) 452-1700 a Fax: (202) 833-3636 Bar Frar,Geco In cooperation with 31909 Hayman Street THE AMERICAN IRON AND STEEL INSTITUTE Hayward, CA 94544 1101 - 17th Street, N.W., 13th Floor (415) 471-2233 Washington, DC 20036 Seattle Phone: (202) 452-7100 a Fax: (202) 463-6573 P.O. Box1346 Mukifteo, WA 98275 (206) 347-83M TABLE OF CONTENTS Survey Report PAGE Summary......................................................................................... Soil Side Service Life Prediction............................................................ i:i Galvanized Coating Condition.............................................................. iii Introduction..................................................................................... 1 Factors Affecting Corrosion.................................................................. 2. Coupon Evaluation............................................................................. 4 Analysisand Modeling........................................................................ 5 ComputerProgram............................................................................ 9 Relationship of Pipe -to -Soil Potential Measurements and Condition of Exterior Plain Galvanized Pipe............................................................ 9 Tables and Graph Table 1 - Sites Examined Through Year Ending 1989.................................. 10 Table 2 - Soil Sample Laboratory Analysis For All Sites ............................... 13 Graph 1 - Frequency Distribution, Soil Sample -Chloride ............................... 22. Graph 2 - Frequency Distribution, Soil Sample -Moisture Content .................... 23 Graph 3 - Frequency Distribution, Soil Sample -pH ..................................... 24 Graph 4 - Frequency Distribution, Soil Sample -Resistivity ............................ 25 Table 3 - Data Used To Perform Statistical Categorical Analysis On Plain Galvanized Exterior Pipes.......................................................... 26 Graph 5 - Predicted Age To Plain Galvanized Corrugated Pipe, Failure From Exterior Corrosion Only, Evaluation Of Galvanized Sites Only .................... 30 Graph 6 - Detailed View Of Graph 5 Where Predicted Life Is Less Than 150 Years Predicted Age To Plain Galvanized Corrugated Pipe, Pipe Failure From Exterior Corrosion Only, Plain Galvanized Sites Only .............. 31 Graph 7 - Predicted Age To Plain Galvanized Corrugated Pipe, Failure From Exterior Corrosion Only, Evaluation Of All Site Data ............................... 32 Graph 8 - Detailed View Of Graph 7 Where Predicted Age Is Less Than 150 Years Predicted Age To Plain Galvanized Corrugated Pipe, Pipe Failure From Exterior Corrosion Only, Evaluation of All Site Data ............... 33 Table 4 - Sample Screen From Pipe Life Prediction Model ............................ 34 Graph 9 - NCSPA Study - Condition Of Galvanized Coating .......................... 34 Graph 10 - Relationship Between Exterior Corrugated Pipe Galvanized Protective Coating And Pipe To Soil Potential As Measured Using A Copper/Copper Sulfate Reference Electrode ................................ 35 FINAL REPORT Condition and Corrosion Survey on the Exterior of Plain Galvanized Corrugated Steel Storm Sewer and Culvert Pipe SUMMARY In the spring of 1986 Corrpro Companies, Inc. undertook the development and exe- cution of a detailed inspection and testing program to evaluate the long term durabil- ity of corrugated steel pipe installed throughout the United States. This report, updating the 1987 and 1988 interim re- ports, provides a complete final analysis of the soil side durability of plain galvanized corrugated steel pipe. During the study period 122 sites across the United States were evaluated. Seventy four sites were plain galvanized and forty eight were asphalt coated. A broad range of site conditions were represented including a soil pH range from 4.1 - 10.3 with resistivities as low as 191 ohm -cm. Soil moisture and chloride content, also durability factors, varied considerably (see graphs 1 - 4). The varying site conditions and ages of the structures provided a broad data base. To ensure control, all site investigations and site data collection were performed by one person, a registered professional engi- neer, following strict protocol developed by Corrpro. Survey results indicate that 93.2 percent (69 sites) of the plain galvanized installations have a soil side service life in excess of 75 years, while 81.5 percent (61 sites) have a soil side service life in excess of 100 years. When site conditions indicate that plain galvanized may not provide the desired service life, study results indicate that the addition of an asphalt coating may have provided a soil side service life in excess of 100 years. From a soil side durability standpoint, this study: 1. Provides a computer model to accu- rately predict the soil side service ]life of plain galvanized installations. The model is to be used within the rangeof the site conditions in the study (see Table 3). 2. Demonstrates that the condition of the galvanized coating on the interior or exterior of the pipe can be accurately assessed for in service structures through simple corrugated pipe -to -soil potential measurements using a copper - copper sulfate reference electrode (see graph 10). i SOIL SIDE SERVICE LIFE PREDIC- TION The IBM PC compatible statistical model developed from this study accurately pre- dicts average service life for sites where durability is limited by soil side corrosion. The model requires measurement of pH, resistivity, moisture content (%) and the chloride ion concentration where the pipe is to be installed. Based on these conditions, the model pre- dicts the condition of the protective galva- nized coating over time. When the galva- nized coating reaches the point that pitting of the steel substrate could begin, the model uses black steel corrosion data from 23,000 black steel, underground storage tank sites to analyze overall durability vs. time. The model analyzes the condition of the galvanized coating such that: 1. P, = the probability that the galva- nized coating covers 100 percent of the exterior surface. 2. P2 = the probability that 21 - 99 percent of the exterior area is covered with zinc. 3. P3 = the probability that less than 20 percent of the exterior area is covered with zinc. The analysis indicates that after the time for P, + P2 to drop below 25 percent, pitting corrosion of the steel substrate may initiate. When P, + P2 = 25 percent, 25 percent of the pipe surface has a 21 - 100 percent zinc coverage. Up to this point, the remaining zinc is adequate to provide cathodic corro- sion protection for the uncoated portions of the pipe which are either black steel, or more than likely, the intermetallic (alloy layer) phase. However, beyond this point the model conservatively assumes the black steel corrosion rate. Once the unprotected steel begins to cor- rode, an analysis of the storage tank data, using the culvert site conditions, indicates that the time to black steel first perforation equals or exceeds 12.5 percent of the total time for P, + PZ to drop below 20 percent. The combined data from these studies indi- cates that the time to first soil side perfora- tion of 16 gauge galvanized corrugated steel pipe: Time to first perforation = [(Age where P, + PZ < 25 %) + (Age where P, + PZ < 20%) x 12.5%]. Based on previous work done by the Na- tional Bureau of Standards, Mr. Richard Stratfull of the California Department of Transportation, studying culvert inverts, defined "average service life" for typical corrugated steel pipe installations as twice the number of years to first perforation. ii This is a reasonable assessment since a minor perforation does not constitute a loss of serviceability in gravity flow culverts or storm sewers. The average soil side ser- vice life then is: Average soil side service life = 2 x [(Age where Pi + PZ < 25%) + (Age where Pi + PZ < 20%) x 12.5 %] When considering average soil side service life versus invert service life predictions, substantial differences in the environment must be recognized. Most methods for es- timating service life were based on the water side (the inside) of the pipe. At- tention was properly focused on the invert of the pipe. The water side invert zone is subject to the erosion corrosion cycle, wet- ting and drying cycles and in some in- stances, significant abrasion loss. These types of corrosion accelerators are not a factor on the soil side of the pipe. Soil side life, quite understandably in most installa- tions, will be substantially longer than water side, invert life. The black steel (storage tank data) used in the model was 16 gauge. Therefore the model does not accommodate added life projections due to the increased thickness of the pipe wall. Use of this data induces significant conservatism also because, it is based on steel not previously galvanized, and therefore, does not recognize the ef- fects of residual galvanizing and the alloy layer formed during galvanizing in slowing the corrosion process. Additionally, the slowing of the corrosion pitting rate with time for thicker gauges cannot be accom- modated. However, these shortcomings add conservatism to the service life esti- mates. When using the program, additional inves- tigation is required for site conditions con- sidered extremely corrosive because of the limited information in the data base for these severe conditions. GALVANIZED COATING CONDITION This study demonstrates that the condition of the galvanized coating can be accurately evaluated by simple pipe to soil potential measurements using a copper -copper sulfate reference electrode. The correlation be- tween potential measurements and the lab- oratory evaluation of the condition of the zinc coating is shown in graph 10. The condition of the exterior zinc coating can be evaluated by taking potential read- ings through the soil cover. For interior coating assessments, potential measure- ments can be taken using a sponge (see coupon evaluation pages 4 & 5) or in a flow condition, the half cell can be floated through the pipe taking potential measure- ments at incremental distances thus evalu- ating the entire invert. iii Knowing the condition of the galvanized coating and the age of the pipe allows an assessment of the pipe's condition and re- maining service life. iv INTRODUCTION In 1986, the field investigation of 21 corru- gated steel storm sewer and culvert pipes located throughout the United States was completed. As a result of that investiga- tion, an interim report dated February, 1987 was prepared and published by the National Corrugated Steel Pipe Association (NCSPA). This first survey report detailed the initial scope of the study and provided a detailed description of the field data gath- ering procedures together with the discus- sion of the laboratory test procedures and conclusions that could be reached from a relatively limited data base of information. In 1987, inspections were performed at an additional 32 sites. The data and an analy- sis of that data were published in a second interim report dated September, 1988. This report presented the first use of statis- tical analysis to explore the ability of fore- casting the mean time to corrosion failure (MTCF) of corrugated pipe due to exterior corrosion of both the galvanized coating and steel substrate in a wide variety of ap- plications. The report went on to state, "At this point, the statistical analysis is only applicable to plain galvanized culverts and storm sewers. It is further restricted to their exterior buried surfaces. This limited scope is based on the following: 1. All exterior surfaces of galvanized pipes with intact asphalt coatings were in excellent condition regardless of age. 2. Interior deterioration was limited to the invert of the pipe. The corrosion in this area is primarily due to the 'erosion corrosion cycle'. This form of corrosion is primarily dependent on flow velocity and the amount and type of particulate material contained in the water. If the water velocity and the particulate material are significant, a paved invert is recommend. The data used in the 1988 analysis con- sisted of measurements taken from 46 soil samples collected in close vicinity to each pipe's exterior surface and reports of visual inspections of plugs of pipe wall removed at these locations. The 46 observations were those where no asphaltic coating had been applied to the pipe since the objective was to access corrosion effects on the gal- vanized coating only." The analysis, performed by Dr. Warren A. Rogers of Warren Rogers Associates, Inc., concluded that it was possible to perform a statistically definitive categorical analysis of the condition of the galvanized coatings based on the measurements of several pa- rameters associated with the adjacent soil. The soil characteristics which were found to be of significance with respect to corro- sion deterioration of the protective galva- nizing coating were soil moisture content, soil moisture resistivity, soil moisture pH and soil moisture chloride ion concentra- tions. In the conclusions, the 1988 report listed two major limitations with respect to the prediction powers of the models pre- sented for the exterior galvanized pipe sur- face as follows: 1. The models were still based on the rel- atively limited data set and the galva- nized condition was determined sub- jectively (e.g. by visual appraisal of the galvanized condition). 2. The study did not attempt to account for the remaining useful life of the car- bon steel pipe after the galvanizing coating is depleted. Because of the above two limitations, it was decided that the remaining sites to be investigated should be uncoated, plain gal- vanized to increase the data base. This in- vestigatory work was carried out in 1988 and 1989. A total of 69 additional sites were examined in that time period of which 56 had plain galvanized exteriors. Table 1 lists the locations of all pipes examined to date, together with their age and type of coating or lining used. The sample coupons and soil samples which were used in the final analysis were based on the total of 162 coupons and soil samples rather than the 46 coupons analyzed in the 1988 report. Thus, this report concentrates exclusively on the ability to analyze or to predict the time to pipe failure due to exterior corro- sion on plain galvanized corrugated steel storm sewer and culvert pipe. Future work may be carried out with respect to the in- vert corrosion issue. Because corrosion is an electrochemical process, the corrosion rate experienced by any buried or submerged metallic structure is related to Ohm's Law. The corrosion current is directly proportional to the volt- age of the corrosion cell and inversely pro- portional to the resistance of the corrosion cell. For years, corrosion engineers have used structure -to -electrolyte as well as other electrical potential measurement techniques to analyze corrosion patterns on under- ground pipelines. During the late 1950's and early 1960's, Dr. Gordon Scott began to evaluate the use of soil resistivity to predict the relative cor- rosivity of the environment for steel rein- forced concrete pipelines. Studying the re- sistivity of soils, he determined that the re- sistivity data was normally distributed if the logarithm of resistivity is used in the analy- sis. Later researchers extended his work to evaluate the probability of corrosion fail- ures versus the logarithm of soil resistivity to steel gas transmission pipelines. These techniques enabled the engineer to develop a priority schedule, by section, for application of cathodic protection for corro- sion control on a programmed basis. These techniques have been expanded to incorpo- rate the use of structure -to -electrolyte po- tential measurements which have provided greater accuracy in the pipeline section se- lection process. In the late 1970's, Dr. Warren Rogers rec- ognized that greater measurement precision and more thorough analysis of corrosion inducing variables needed to be conducted in order to determine the Mean Time to Corrosion Failure (MTTCF) and Probability of Leak for Underground Storage Tanks (USTs). Using data gathered from the backfills of an extensive number of both failed and sound systems, he was able to develop a model to determine MTCF for USTs using comprehensive measurements obtained at the site. This model has been applied at over 23,000 sites involving over 70,000 steel USTs and refined and verified based upon observations recorded following the excavation of tank systems previously evaluated. Dr. Rogers's investigations have disclosed additional environmental variables which affect the rate of corrosion. These are: Moisture Content - Under most circum- stances, corrosion rates are directly related to soil moisture content. However, for galvanized steel storm sewer and culvert pipe, the soil moisture content primarily af- fects the activity of any chloride ions pre- sent and the chlorides' acceleration of the corrosion. Where the soil moisture content was below, 17.5 percent, the chloride ion concentration did not have a significant af- fect on the corrosion rate of the zinc coat- ing. However, when the moisture content exceeds 17.5 percent, the chloride ion concentration has a significant bearing on the corrosion rate. Soil moisture must be accurately measured in accordance with the method described by ASTM D2216. pH - The lower the pH (below a neutral value of 7.0), the greater will be the corro- sion rate. As pH increases above 10, con- ditions become increasingly less corrosive. pH must be accurately measured in accordance with the method described by ASTM 131293. Chlorides - The presence of increasing concentrations of chloride ions lowers the resistivity of soil and water and acts as a cathode depolarizer. Increasing concentra- tions of chlorides in the soil moisture will increase the corrosion rate if adequate soil moisture is present. Chloride content must be accurately measured in accordance with the method described by ASTM D512 for Method B. 3 Resistivity (Conductivity) - The higher the resistivity (or the lower the conductivity) of the soil, the lower the corrosion rate. Resistivity must be accurately measured in accordance with the method described by ASTM 57, Soil box. It is important to recognize that there were substantial variations in corrosion factors from site to site in this study. Specific summaries are provided in graphs 1-4. This broad range of corrosion factors greatly enhances the value of the data and its applicability and accuracy when evalu- ating specific site conditions against the data base. When evaluating a specific site, if one or more environmental factors approaches the extremes of the data base, care should be taken to ensure that the specific site conditions, in combination, do not exceed the corrosivity limits of the data base. This is limited to the evaluation of very aggressive sites where the combined site conditions may provide an extreme deviation from actual data base site conditions and adversely affect the model's accuracy. Variations within a particular site, due to such things as seasonal changes in moisture content, etc. can be accurately addressed using a weighted average evaluation. For example, if a culvert were being considered for installation in a desert area, the percent moisture content in the soil will probably be below 17 1/2 percent for 8 months each year. For this example, the life of the cul- vert due to exterior corrosion should be calculated for both conditions. The pre- dicted life would then be calculated by: 1) multiplying the years life calculated for the d-ty condition by 66 2/3 percent, 2) multiplying the years life calculated for the wet condition by 33 1/3 percent, and 3) adding the resultant lifes obtained in steps 1 and 2 together to determine the overall expected life. The additional life due to the corrosion time of the black steel is predicated on 0.064" (16 gage). When using greater steel thicknesses the following standard multipliers based on work by Stratfull and others may be used: Wall Thickness Multiply Service Life by 0.079" (14 ga.) 1.23 0.019" (12 ga.) 1.69 0.138" (10 ga.) 2.15 0.168" (8 ga.) 2.62 COUPON EVALUATION To evaluate the condition of each of the 162 coupons collected in this study, each coupon was first bristle brushed clean and the surface condition of both the exterior and interior of the coupon was photo doc- umented. The individual coupons for each 4 corrugated pipe were sealed in laboratory specimen jars and forwarded to Corrpro's West Chester, Pennsylvania failure analysis laboratory. The first step of their evaluation involved measuring the electrical potential of the exterior surface with respect to a cop- per/copper sulfate reference electrode. The measurement was performed by placing a donut sponge whose outside diameter was slightly less than the coupon outside diam- eter and whose inside diameter was slightly greater than the hole in the center of each coupon. The tip of the copper/copper sul- fate reference electrode was then placed in contact with a moist sponge and a high in- put impedance digital voltmeter was used to measure the potential difference between this reference electrode and the metal sur- face in contact with the sponge. The intent of this measurement was to use the mea- sured potential data to see if there was a strong correlation between this measure- ment and the percent of galvanizing re- maining on the coupon surface. Following the measurement of each coupon's potential, the coupon was cleaned using a "cathodic" cleaning process. This consisted of immersing each coupon in a highly conductive solution and connecting the metallic coupon to the negative terminal of a DC power supply while the positive terminal of the supply was connected to a precious metal oxide coated titanium anode. Sufficient current was passed between the anode element and the cathodic coupon to .generate hydrogen gas at the metal/electrolyte interface of the coupon. This hydrogen gas removed all non-metallic contaminates from the surface of the coupon. After the coupon had been cleaned, it was immersed in a saturated copper sulfate so- lution. This resulted in staining those sur- face areas which had zinc on them to a black color while the area where steel was exposed (no zinc coating) turned a copper color. A clear mylar graticule with 1/10 inch by 1/10 inch graduations was then placed over the coupon and the number of squares were counted which were black in color versus the number of squares which were copper in color to establish the per- cent surface area where the zinc protective coating was still intact. This coupon sur- face condition information, together with the corresponding soil information data, was sent to Dr. Rogers for analysis (Table 3). ANALYSIS AND MODELING The first step in the analysis was to statisti- cally correlate the condition of the zinc coating on the outside surface of the coupons with respect to the impact of age, moisture content, electrical resistivity, chlorides, pH and sulfide conditions of the site. The data consisted of 162 ob- 5 servations of the percentages of zinc which remained from culverts of various ages. As was previously reported (second interim re- port), it proved feasible to derive categori- cal predictions from the data, that is, predi- cations as to certain limited categories or intervals of zinc removal that would be ob- served as a function of the measured vari- ables. This further analysis confirmed and refined the findings of the earlier work. The pre- vious study had used visual estimates of the amount of zinc remaining on each coupon surface. The more precise measurement methods used in this study enhanced the ability to perform the categorical analysis. In addition, the much larger data base has increased the accuracy of the predictive models. Finally, a broader range of observed pH substantially improved the predictive power of the model overall and particularly the impact of acidity on predictions. However, the number and configuration of categories which can be reliability esti- mated is constrained by the reduced number of observations in a range from 1 percent to 99 percent zinc remaining. The analysis is sensitive to imbalances in sample sizes within categories. Other categories than those presented here can be estimated with varying levels of confidence. Several anal- yses were performed as follows: Analysis 1: Three categories: zinc 100 percent intact, zinc 21 to 99 percent intact, and zinc 0 to 20 percent intact. Analysis 2: Zinc 100 percent intact, zinc 86 to 99 percent intact, zinc 20 to 85 per- cent intact, and zinc 0 to 19 percent intact. Analysis 3: Zinc 100 percent intact, zinc 1 to 99 percent intact, and zinc 0 percent in- tact. Analysis 4: Zinc 21 to 100 percent intact, zinc 0 to 20 percent intact. To categorize the condition of the external zinc coating, Analysis 1 and 3 utilized 3 categories of zinc condition while Analysis 2 used 4 categories and Analysis 4 used only 2. Analysis I was selected as the ba- sis for modeling because it provided the most uniform distribution of the data set in each category. Each analysis consisted of deriving func- tional forms and estimating parameters for data to fit: In P;/PN = f; (Age, Res, pH, Chlind) i=1,2....N Pi+PZ+...PN=1 where N = Number of Categories li Age = Age in years when pipe was inspected or if using prediction model, the age when the pipe would fail due to external corro- sion Res = Electrical resistivity of the soil sample in ohm -cm pH = pH of the soil (e.g. 6.4 8.9, etc.) Chlind = Chloride; ion concentra- tion in parts per million if moisture; exceeds 17.5 percent, I otherwise Moisture Content = Percent moisture content in soil by weight Pi = Fraction of sites where the percent of zinc coat- ing relevant to the ith cat- egory would be observed. i+1,2....N The various coating percentage categories were chosen because they result in roughly balanced sample sizes and were considered meaningful from a corrosion standpoint. The following estimates were derived for the categories listed where: C;=1nP- p N and, therefore, !M WO 1+C1+C2+...CN.1 i==1,2....N-1 1 + C1 + C2 + ... CN-1 Percent Zinc remaining ANALYSIS 1 Categories 100 21-99 0-20 C1 = AgCS-2.7609 x ReS0.198 x exp(1.2926 x pH) x Chlind-09435 C2 = Age-1.4344 x Res .2942 X exp(0.4399 x pH) x Chlind-0.5894 ANALYSIS 2 Categories 100 86-99 20-85 0-19 C1 = Age-3.4763 x Res0.2338 X exp(1.6678 x pH) x Chlind-1.2655 C2 = Age-3.5083 X Res 0.3669 X exp(1.521.6 x pH) x Chlind-20496 C3 = Age:-0.1665 x Res0.1734 x exp(- 0.4751 x pH) x Chlind-0.0673 7 ANALYSIS 3 Categories 100 1-99 0 C, = Age-2.4126 x Reso.0908 x exp(1.2858 x pH) x Chlind-0.8654 C2 = Age-0.6001 x Res 0.0773 x exp(0.3327 x pH) x Chlind-0.2697 ANALYSIS 4 Categories 21-100 0-20 C, = Age-2.1032 x ResO.2902 x exp(0.8350 x pH) x Chlind-0.5657 The parameter estimates are all consistent with corrosion theory. This analysis, of course, only addresses the time necessary to achieve various levels of degradation of the protective galvanized coating when subjected to a wide variety of corrosive in- fluences. It does not address the further degradation which would ensue to the steel structure once the protective coating is re- moved. Dr. Rogers, however, did have an extensive data set (in excess of 23,000 sites with 70,000 samples throughout the United States) on corrosion effects on other unpro- tected mild steel structures. This data set analyzes the time to achieve first perfora- tion of mild steel plate which is experienc- ing pitting corrosion. To apply that index to the culverts, it was determined that sig- nificant protection of the surface would cease when less than 25 percent of the surface area had galvanized coating remaining. Beyond this point, the black steel data provided the number of years for 0.064 inch (16 gauge) corrugated steel pipe to reach first perforation. The times to failures so derived varied with the corrosion conditions. However, they are consistently above 12.5 percent of the time required to reach the 20 percent level of the remaining intact zinc coating. Using Categorical Analysis 1, where P, is equal to 100 percent zinc remaining and P2 is equal to 21 to 99 percent zinc remaining, would result in a time to first perforation of [Age where Pi + P2 < 25%) + (Age where P, + P2 < 20%) x 12.5%]. Fur- ther, previous work done by the National Bureau of Standards and Mr. Richard Strat- full with the California Department of Transportation indicates that the average service life of a corrugated steel storm sewer and culvert pipe is predicted to be twice the number of years to that of first perforation. Thus, the formula for calcu- lating the time to culvert failure is equal to 2 x [(Age where Pi + P2 < 25%) + (Age where Pi + P2 < 20%) x 12.5%]. Using the above formula, the predicated age to plain galvanized corrugated pipe failure from exterior corrosion only was calculated for the 162 samples. This data is shown on Graphs 5 and 6. As can be seen from Graph 6, only 38 of the plain galva- nized samples were predicted to have an expected useful life of less than 100 years. Graphs 7 and 8 apply the same analyses to 0 all site data including those which had as- phalt coated exteriors. Had these pipes all been plain galvanized steel, only 56 of the total of 340 soil samples would have a pre- dicted a useful life of less than 100 years. COMPUTER PROGRAM In order to aid the user in predicting aver- age of soil side service life, a Lotus spread- sheet was developed with macros to allow simply inputting the four input variables (soil moisture content, soil resistivity, pH, and chloride ion concentration). The pro- gram then automatically calculates the time to PI + PZ = 25 percent and then calculates the time to corrosion failure, due to exterior corrosion as: Average soil side service life = 2 x [(Age where P, + P, < 25 % + (Age where P, + P, < 20%) x 12.5 %] To avoid needing to use the Lotus 1-2-3 software spreadsheet program, the work - sheet was compiled using a program called Baler, manufactured by Baler Software Corporation. This program generates a standalone spreadsheet which operates in a manner equal the original Lotus program. It includes all the custom macro programs and allows protection of calculation ranges so that inadvertent formula damage cannot occur. The program is run on virtually all IBM PC's or PC compatible computers uti- lizing DOS 3.0 or higher and requires only a single floppy drive system. The graphi- cal portion of the program is compatible with CGA, EGA, and VGA monitors both in monochrome and color. The floppy disk program is accompanied by a users manual. A typical printout of the predicted age for a given data set is included in Table 4 and a graphical analysis of this data is provided in Graph 9. RELATIONSHIP OF PIPE -TO -SOIL POTENTIAL MEASUREMENTS AND CONDITION OF EXTERIOR PLAIN GALVANIZED PIPE The analysis of potential measurements re- vealed an interesting pattern not previously noted. This relationship is presented in Graph 10. To create this graph, first the running average of the potential measure- ment was calculated versus the percent gal- vanizing remaining on the surface for each measurement. This was to smooth out some of the data scatter that existed. It can be seen from that graph that there is a steep fall off in the percent galvanizing coating remaining intact between the potentials of - 600 and -800 millivolts with respect to a copper/copper sulfate reference electrode. The graph demonstrates that if a potential of -600 millivolts were measured on a buried, plain galvanized pipe, it would be reasonable to assume that the protective galvanized coating had deteriorated to a point where pitting corrosion could initiate. E TABLE 1 SITES EXAMINED THROUGH YEAR ENDING 1989 SITE CITY, STATE OWNER YEAR' AGE-- COATING PIPE MANUFACTURER 4 Dugger, IN Indians Dept. of Highways 1937 49 Lined Armco Const. Products, Middletown, OR 6 Jefferson City, MO City of Jcfferson City 1945 41 PG 7 Lebanon, MO City of Lebanon 1947 39 PG 17 Council Grove, KS City of Council Grove 1930 56 AC 18 Topeka, KS City of Topeka 1930 56 AC&P Armco 21 Adrian, MI City of Adrian 1958 28 Lined Republic Steel Corporation, Canton, OR 22 Lexington, NC City of Lexington 1959 27 Lined 25 Chambersburg, PA Borough of Chamberaburg 1961 25 Lined 28 Virginia Beach, VA Oceans Naval Air Station 1958 28 AC&P 28A Virgins Beach, VA Oceans Naval Air Station 1958 28 AC&P 29 Bethlehem, PA Bethlehem Steel Corp. 1961 25 Lined Republic Steel Corporation 30 Pennsauken, NJ Township of Pennsauken 1967 19 Lined 31 Narberth, PA Borough of Narberth 1961 25 Lined Republic Steel Corporation 33 Halethorpe, MD Baltimore County 1936 51 AC&P 34 Edmondson Hts., MD Baltimore County 1956 31 Lined 36 Wilmington, OR Airbourne Express 1958 28 AC&Lined Republic Steel Corporation, Canton, OR 41 Parma, OR City of Parma 1960 26 Lined Republic Steel Corporation, Canton, OR 43 Salt Lake City, UT Salt Lake City 1913 73 PG 44 Salt Lake City, UT Salt Lake City 1913 73 PG 51 Southeast Place, TX City of Southeast Place 1925 61 AC 52 Shreveport, LA City of Shreveport 1960 26 AC Armco 53 Tucson, AZ City of Tucson 1955 31 PG Armco 54 Tucson, AZ City of Tucson 1956 30 PG Garland Steel Co., Phoenix, AZ 55 San Diego, CA City of San Diego 1959 28 Lined 56 Alliance, OR Stark County 1935 52 PG Republic Steel Corporation 57 Pocatello, m City of Pocatello 1914 73 PG Armco 58 Pocatello, ID City of Pocatello 1914 73 PG Armco 59 Homer, GA Georgia DOT 1936 51 AC&P 60 W. of Sopenon, GA State of Georgia 1937 50 PG Armco 61 Geneva, GA State of Georgia 1936 51 AC&P 62 Atlanta, GA Fulton Co. Public Works 1966 21 AC&P Armco 63 Brevard, NC U.S. Dept. of Interior 1939 48 AC&P 64 Marion, NC U.S. Dept. of Interior 1939 48 AC&P 65 Waynesboro, VA U.S. Dept. of Interior 1936 51 PG 66 Holden, MO MO Hwy & Trans Comm. 1950 37 PG Armco 67 Eolia, MO MO Hwy & Trans Comm. 1949 38 PG MO Boiler 68 Greentop, MO MO Hwy & Trans Comm. 1950 37 PG Republic Steel Corporation 69 Helene, MO MO Hwy & Trans Comm. 1950 37 PG Wheeling 70 Ukiah, OR Oregon DOT 1950 37 AC&P 71 Grants Pass, OR Oregon DOT 1939 48 PG 73 Valley Junction, OR Oregon DOT 1948 39 AC 74 Cosmopolis, WA Washington DOT 1932 55 AC 75 Amboy, WA Clark County 1948 39 AC&P 76 Washougal, WA Washington DOT 1935 52 AC 77 Bickleton, WA Klickitat County 1947 40 PG Republic Steel Corporation 80 Beacon, NY City of Beacon 1933 54 PG Republic Steel Corporation 81 S. Burlington, VT St of VT Agency of Trans 1961 26 AC&P 82 Westminster, VT St of VT Agency of Trans 1962 25 AC&P �Q TABLE 1 (continued) SITE CrrY, STATE 90 91 92 93 94 101 102 103 104 105 106 107 110 ill 112 113 115 116 117 118 119 120 121 130 131 140 141 142 143 150 151 152 153 154 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 Jacksonville, FL Clarksville, FL Old Town, FL Brookrville, FL Lakeport, FL Beverly Hills, CA Fullenown, CA S. of L.enwood, CA Near Zamora, CA Near Pepperwood, CA Near Manchester, CA North of Goleta, CA Raleigh, NC Roanoke, VA Roanoke, VA Danville, VA Broadview, MT Three Forks, MT Cardwell, MT Superior, MT Whitefish, MT Seeley Lake, MT Sheridan, WY Omaha, NE Neleigh, NE Englewood, CO Colorado Springs, CO Colorado Springs, CO Pueblo, CO Keene, NY Dublin, NY Bryon, NY New Albion, NY Cortland, NY Near Waynesboro, VA Near Waynesboro, VA Near Waynesboro, VA Near Waynesboro, VA Near Waynesboro, VA Near Waynesboro, VA Mint Springs, VA Milleradaughteq VA Singing Spring, VA Keezletown, VA Weyen Cave, VA Dyke, VA Crozet, VA Fairview Beach, VA Fredricksburg, VA Occoquan, VA SITES EXAMINED THROUGH YEAR ENDING 1989 OWNER Florida DOT Florida DOT Florida DOT Florida DOT Florida DOT City of Beverly Hills City of Fullerton Cadtram Dist. VHI Yolo County Caltmm Dist. I Caltram Dist. I Caltram K-Mart Power Equipment Corp. Roanoke Airport City of Danville School Yellowstone County MT DOT MT DOT MD DOT MT DOT MT DOT City of Sheridan City of Omaha City of Neleigh City of Englewood City of Colorado Springs City of Colorado Springs City of Pueblo NY DOT NY DOT NY DOT NY DOT NY DOT U.S. Dept. of Interior U.S. Dept. of Interior U.S. Dept. of Interior U.S. Dept. of Interior U.S. Dept. of Interior U.S. Dept. of Interior VA DOT VA DOT VA DOT VA DOT VA DOT VA DOT VA DOT VA DOT VA DOT VA DOT YEAR- AGE" COATING 1939 1941 1946 1951 1960 1926 1958 1926 1937 1931 1935 1941 1968 1963 1964 1959 1961 1952 1947 1948 1936 1952 1963 1959 1934 1974 1959 1957 1952 1955 1957 1940 1969 1972 1936 1936 1936 1936 1936 1936 1978 1973 1968 1992 1970 1968 1978 1948 1980 1972 11 48 46 41 36 27 62 30 62 51 57 53 47 20 25 24 30 27 36 41 40 52 36 25 29 54 14 29 31 36 33 31 48 19 16 53 53 53 53 53 53 11 16 21 7 19 21 11 41 9 17 AC&P AC&P AC&P AC&P AC PG AC PG PG PG AC AC&P AC&P AC&P PG PG PG PG PG PG AC&P Lined PG Lined AC Lined AC PG PG PG PG PG PG PG PG PG PG PG PG PG PG PG PG PG PG PG PG PG Armco Armco Armco Armco Armco Republic Steel Armco Armco Armco Armco Armco Republic Steel Republic Steel Republic Steel TABLE I (continued) SITES EXAMINED THROUGH YEAR ENDING 1989 SITE CITY. STATE OWNER YEAR# AGE" COATING PIPE MANUFACTURER 176 Swiftcmek Rem, VA VA DOT 1979 10 PG Armco 177 Cheater, VA VA DOT 1981 8 PG 178 Dillwyn, VA VA DOT 1935 54 PG 200 Jerusalem, AR AR State Hwy & Trans. Dept. 1964 25 PG 201 Jerusalem, AR AR State Hwy & Trans. Dept. 1964 25 PG 202 Ward, AR AR State Hwy & Trans. Dept. 1956 33 PG 203 Wheatley, AR AR State Hwy & Trans. Dept. 1964 25 PG 210 Rabum, KS Shawnee County 1967 22 PG 211 Topeka, KS Shawnee County 1969 20 PG Armco 212 Richland, KS Shawnee County 1977 12 PG 213 Rosaville, KS Shawnee County 1960 29 PG 214 Silver Lake, KS Shawnee County 1948 41 PG Armco 215 Lansing, KS Leavenworth County 1968 21 PG 216 Lowemont, KS Leavenworth County 1971 18 PG 217 Easton, KS Leavenworth County 1969 20 PG 218 Fall Leave, KS Leavenworth County 1974 15 PG 219 Rena, KS Leavenworth County 1964 25 PG 220 Linwood, KS Leavenworth County 1971 18 PG 221 Reno, KS Leavenworth County 1964 25 PG USS - Ambridge 222 Rasehor, KS Leavenworth County 1970 19 PG 223 Tonganoxie, KS Leavenworth County 1968 21 PG 224 Fairmount, KS Leavenworth County 1968 21 PG 225 Jarbalo, KS Leavenworth County 1974 15 PG 226 Springdale, KS Leavenworth County 1971 18 PG Site numbers are not consecutive since site numbering and information were taken from a previous (1978) AISI Storm Sewer Survey. Note: * Year installed ** Age at inspection Coating Types PG = Plain Galvanized AC = Asphalt Coated AC&P = Asphalt Coated and Paved Lined = 100% Asphalt Lined 12 TABLE 2 SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (% dry weight) CONDUCTIVITY (micromohs) RESISTIVITY (ohm -cm) Ph SULFIDE (ppm) CHLORIDE (ppm) 4 12:00 14.8 552 1812 8.0 0 141 4 4:00 15.2 388 2577 7.8 0 100 4 8:00 17.2 272 3676 7.7 0 62 6 12:00 13.2 256 3906 6.6 0 42 6 4:00 21..0 109 9174 8.2 0 42 6 8:00 21..2 169 5917 7.8 0 71 7 12:00 33.3 190 5263 7.3 0 48 7 4:00 20.6 104 9615 6.9 0 37 7 8:00 21.9 71 14085 6.4 0 41 7 upstream + 16.1 388 2577 7.3 0 18 17 12:00 21.6 201 4975 8.0 0 148 17 4:00 29.4 119 8403 8.0 0 96 17 8:00 24.0 127 7874 7.8 0 68 18 12:00 13.9 263 3802 7.6 0 65 18 4:00 7.0 141 7092 8.5 0 46 18 8:00 15.2 272 3676 7.8 0 48 21 12:00 3.7 990 1010 7.7 0 227 21 4:00 9,.3 374 2674 7.9 0 71 21 8:00 18.4 538 1859 7.9 0 124 22 12:00 11.8 62 16129 8.4 0 9 22 4:00 27.4 131 7634 7.6 0 11 22 8:00 20.0 58 17241 8.4 0 7 25 12:00 10.2 214 4673 7.8 0 17 25 4:00 14.7 163 6135 8.2 0 2 25 8:00 17.8 145 6897 8.2 0 2 28 12:00 28 4:00 17.0 86 11628 6.5 0 7 28 8:00 15.1 162 6173 6.1 0 16 28A 12:00 28A 4:00 16.0 51 19608 5.5 0 14 28A 8:00 29 12:00 8.9 296 3378 8.3 0 16 29 4:00 29 8:00 314.0 3185 8.1 0 23 30 12:00 30 4:00 19.2 196 5102 7.0 0 3 30 8:00 18.2 527 1898 7.2 12.453 2 31 12:00 11.0 159 6289 7.5 0 3 31 4:00 31 8:00 31.3 186 5376 7.2 0 5 33 12:00 33 4:00 21.9 117 8547 6.6 0 4 33 8:00 24.7 33 30303 7.2 0 3 34 12:00 24.6 152 6579 6.2 0.058 29 34 4:00 35.5 537 1862 5.8 1.309 42 34 8:00 31.5 252 3968 5.9 3.438 17 13 TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (°% dry weight) CONDUCTIVITY (micromohs) RESISTIVITY (ohm -cm) Ph SULFIDE (ppm) CHLORIDE (ppm) 36 12:00 8.9 223 4484 8.2 0 307 36 4:00 36 8:00 41 12:00 17.1 316 3165 8.0 0 130 41 4:00 28.9 273 3663 8.0 0 62 41 8:00 14.0 202 4950 8.3 0 46 43 12:00 43 4:00 43 8:00 5.8 79 12658 8.7 0 6 44 12:00 12.3 754 1326 9.1 0 175 44 4:00 14.6 239 4184 8.6 0 30 44 8:00 20.4 207 4831 8.4 0 12 51 12:00 12.7 157 6369 8.2 0 6 51 4:00 20.5 331 3021 7.6 0.116 13 51 8:00 12.3 121 8264 8.2 0 12 52 12:00 8.1 83 12048 8.3 0 29 52 4:00 8.8 91 10989 8.0 0 11 52 8:00 7.6 137 7299 8.1 0 23 53 12:00 53 4:00 11.2 95 10526 8.3 0 3 53 8:00 8.8 69 14493 8.7 0 6 54 12:00 54 4:00 4.4 312 3205 8.1 0 5 54 8:00 9.0 58 17241 8.3 0 5 55 12:00 9.2 153 6536 8.7 0 10 55 4:00 10.1 199 5025 8.8 0 12 55 8:00 10.4 284 3521 9.0 0 42 56 12:00 12.9 98 10204 8.1 0 7 56 4:00 16.6 213 4695 9.7 0 9 56 8:00 11.2 282 3546 10.3 0 13 57 12:00 57 4:00 25.3 197 5076 8.4 0 14 57 8:00 29.1 416 2404 8.6 0 30 58 12:00 10.7 541 1848 8.6 0 46 58 4:00 24.1 450 2222 8.5 0 62 58 8:00 16.7 616 1623 8.2 0 77 59 12:00 59 4:00 21.0 31 32258 7.0 0 2 59 8:00 60 12:00 12.7 21 47619 6.5 0 5 60 4:00 11.9 37 27027 7.1 0 3 60 8:00 11.0 20 50000 6.9 0 2 60 upstream 15.3 86 11628 6.2 0 9 61 12:00 20.8 30 33333 7.0 0 5 61 4:00 22.2 29 34483 7.1 0 2 61 8:00 23.9 34 29412 7.1 0 2 14 TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT I % dry weight) CONDUCTIVITY (mirmmohs) RESISTIVITY (ohm -cm) Ph SULFIDE (ppm) CHLORIDE (ppm) 62 12:00 28.1 16 62500 6.4 0.029 3 62 4:00 24.8 35 28571 6.9 0.032 2 62 8:00 29.1 11 90909 6.6 0.023 1 63 12:00 35.9 79 12658 4.1 0 2 63 4:00 63 8:00 64 12:00 25.6 63 15873 4.2 0 1 64 4:00 64 8:00 65 12:00 16.8 25 40000 5.6 0 1 65 4:00 65 8:00 66 12:00 11.9 67 14925 7.7 0 3 66 4:00 21.4 119 8403 7.4 0 3 66 8:00 33.9 140 7143 7.3 0 4 66 upstream 34.9 215 4651 7.7 0 24 67 12:00 21.3 71 14085 7.5 0 4 67 4:00 2:3.5 123 8130 7.5 0 10 67 8:00 2:3.7 179 5587 7.3 0 8 67 upstream 3:3.3 376 2660 7.7 0 47 68 12:00 15.2 32 31250 7.9 0 3 68 4:00 13.9 85 11765 8.0 0 15 68 8:00 12.6 87 11494 8.0 0 5 68 upstream 26.2 320 3125 7.9 0 20 69 12:00 19.0 96 10417 8.2 0 4 69 4:00 37.1 136 7353 7.6 0 8 69 8:00 213.3 116 8621 7.7 0 9 69 upstream 25.5 477 2096 7.8 0 90 70 12:00 70 4:00 39.5 39 25641 6.7 0 4 70 8:00 38.6 23 43478 6.8 0 2 71 12:00 71 4:00 36.0 49 20408 6.6 0 4 71 8:00 23.0 74 13514 6.5 0 3 71 upstream 20.4 73 13699 6.4 0 18 73 12:00 8.4 84 11905 5.8 0 2 73 4:00 12.4 17 58824 7.2 0 3 73 8:00 14.0 22 45455 7.2 0 4 74 12:00 4:[A 19 52632 6.2 0 2 74 4:00 56.1 15 66667 6.0 0 2 74 8:00 76.0 19 52632 6.0 0 2 75 12:00 24.3 14 71429 7.1 0 2 75 4:00 71.2 15 66667 6.7 0 2 75 8:00 60.1 11 90909 6.9 0 5 76 12:00 40.5 270 3704 5.8 0 7 76 4:00 15 TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (% dry weight) CONDUCTIVITY (micromohs) RESISTIVITY (oHmcm) Ph SULFIDE (ppm) CHLORIDE (PPm) 76 8:00 73.0 16 62500 6.9 0 3 77 12:00 2.4 73 13699 6.9 0 4 77 4:00 7.0 13 76923 7.3 0 2 77 8:00 12.2 15 66667 7.6 0 3 77 upstream 21.4 78 12821 6.7 0 8 80 12:00 9.8 257 3891 7.4 0 65 80 4:00 20.8 207 4831 7.0 0.067 39 80 8:00 19.3 205 4878 7.0 0.002 37 81 12:00 22.7 140 7143 7.0 0 19 81 4:00 50.7 100 10000 6.9 0 13 81 8:00 28.7 62 16129 7.1 0 5 82 12:00 18.5 64 15625 7.3 0 8 82 4:00 16.9 33 30303 7.3 0 6 82 8:00 90 12:00 1.8 9 111111 6.8 0 1 90 4:00 25.6 35 28571 6.4 0 2 90 8:00 11.3 91 10989 6.4 0 5 91 12:00 4.4 16 62500 6.4 0 1 91 4:00 7.3 13 76923 6.6 0 1 91 8:00 12.3 15 66667 6.4 0 1 92 12:00 1.4 44 22727 6.1 0 2 92 4:00 32.4 33 30303 5.5 0 1 92 8:00 93 12:00 11.5 41 24390 7.4 0 2 93 4:00 10.5 37 27027 7.5 0 2 93 8:00 14.4 31 32258 7.3 0 2 94 12:00 11.6 37 27027 7.7 0 2 94 4:00 24.7 46 21739 7.5 0 2 94 8:00 17.8 35 28571 7.7 0 2 101 12:00 18.0 574 1742 8.1 0 34 101 4:00 22.9 436 2294 7.2 0 55 101 8:00 20.4 353 2833 7.9 0 75 102 12:00 102 4:00 19.8 445 2247 8.1 0 72 102 8:00 10.6 415 2410 8.3 0 72 103 12:00 1.4 70 14286 8.8 0 12 103 4:00 1.6 71 14085 8.9 0 11 103 8:00 2.9 242 4132 8.3 0 25 104 12:00 8.5 110 9091 8.0 0 21 104 4:00 16.1 44 22727 5.7 0 12 104 8:00 11.1 73 13699 8.1 0 12 104 upstream 35.2 550 1818 5.8 0 43 105 12:00 12.9 76 13158 6.6 0 16 105 4:00 105 8:00 105 upstream 31.9 51 19608 5.6 0 8 16 TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (% dry weight) CONDUCTIVITY (micromohs) RESISTIVITY (Ohm -cm) Ph SULFIDE (PPM) CHLORIDE (PPM) 106 12:00 5.0 34 29412 7.4 0 12 106 4:00 37.9 112 8929 7.0 0 40 106 8:00 106 upstream 30.1 131 7634 6.5 0 26 107 12:00 41.5 818 1222 8.0 0 105 107 4:00 17.8 381 2625 8.1 0 38 107 8:00 23.6 318 3145 8.2 0 35 110 12:00 36.7 282 3546 5.9 0 18 110 4:00 40.0 16 62500 6.0 0 7 110 8:00 34.2 24 41667 5.4 0 13 Ill 12:00 15.1 74 13514 7.8 0 7 Ill 4:00 22.4 118 8475 7.5 0 6 Ill 8:00 112 12:00 112 4:00 28.7 74 13514 6.7 0 6 112 8:00 31.8 186 5376 7.8 0 7 113 12:00 23.9 128 7813 4.8 0 13 113 4:00 30.4 116 8621 6.9 0 13 113 8:00 32.4 80 12500 5.8 0 15 115 12:00 3.9 784 1276 6.9 0 100 115 4:00 115 8:00 20.4 365 2740 7.2 0 23 115 upstream 1.1 452 2212 8.0 0 43 116 12:00 4.7 1474 678 7.0 0 24 116 4:00 9.8 522 1916 7.4 0 35 116 8:00 32.0 743 1346 7.3 0 52 116 upstream 7.6 3724 269 7.8 0 31 117 12:00 23.4 307 3257 7.6 0 9 117 4:00 27.3 277 3610 7.8 0 9 117 6:00 31.2 321 3115 7.5 0 12 117 8:00 28.5 359 2786 7.4 0 16 117 upstream 19.1 745 1342 7.6 0 66 118 12:00 118 4:00 23.7 246 4065 7.4 0 5 118 8:00 11.9 332 3012 7.4 0 7 119 12:00 1.7 136 7353 7.5 0 15 119 4:00 10.5 285 3509 7.0 0 100 119 8:00 119 upstream 58.9 384 2604 7.1 0.113 48 120 12:00 1.3 204 4902 7.1 0 33 120 4:00 9.5 126 7937 7.6 0 64 120 6:00 12.4 577 1733 7.0 0 110 120 8:00 11.8 112 8929 7.6 0 32 120 upstream 6.5 216 4630 7.1 0 28 121 12:00 20.3 380 2632 7.5 0 9 121 4:00 28.0 577 1733 7.3 0 7 17 TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (% dry weight) CONDUCTIVITY - (micromohs) RESISTIVITY (ohm -cm) '... Ph SULFIDE (ppm) CHLORIDE (Ppm) 121 8:00 26.0 343 2915 7.5 0 14 130 12:00 23.6 236 4237 8.1 0 23 130 4:00 34.3 540 1852 8.1 1.2 33 130 8:00 26.0 388 2577 7.7 0.6 29 131 12:00 12.8 416 2404 9.0 0 47 131 4:00 15.0 388 2577 8.7 0 65 131 6:00 14.8 564 1773 7.8 0 25 131 8:00 16.9 521 1919 8.5 0 49 140 12:00 1.0 22 45455 7.6 0 6 140 4:00 10.7 69 14493 7.7 0 74 140 8:00 5.6 68 14706 8.2 0 12 141 12:00 15.9 181 5525 8.6 0 11 141 4:00 13.4 187 5348 8.2 0.1 9 141 8:00 25.5 223 4484 8.0 0 26 142 12:00 19.8 2772 361 6.2 0 29 142 4:00 24.5 2856 350 6.7 0 29 142 8:00 24.5 2472 405 6.4 0 28 143 12:00 9.1 5244 191 7.8 0 170 143 4:00 26.1 468 2137 8.5 0 35 143 8:00 28.1 672 1488 8.3 0 39 150 12:00 12.0 278 3597 6.8 0 44 150 4:00 10.0 38 26316 7.6 0 23 150 8:00 8.0 27 37037 7.2 0 12 150 upstream 21.6 117 8547 6.0 0 4 151 12:00 12.0 115 8696 8.7 0 12 151 4:00 13.1 168 5952 8.5 0 13 151 8:00 16.9 254 3937 8.1 0 19 151 upstream 54.8 807 1239 7.1 0.176 95 152 12:00 11.7 112 8929 8.6 0 21 152 4:00 6.0 192 5208 9.4 0 20 152 8:00 13.6 109 9174 8.4 0 10 152 upstream 33.7 748 1337 7.2 0 105 153 12:00 20.3 150 6667 7.9 0 110 153 4:00 20.4 150 6667 8.0 0 21 153 8:00 19.5 227 4405 7.5 0 32 153 upstream 126.8 211 4739 6.6 0.237 17 154 12:00 3.0 100 10000 8.7 0 18 154 4:00 8.7 91 10989 8.8 0 15 154 8:00 5.5 148 6757 8.4 0 27 154 upstream 43.5 687 1456 7.2 0 44 160 12:00 24.6 68 14706 7.4 0 9 160 6:00 56.0 131 7634 7.0 0 33 160 upstream 50.3 56 17857 6.5 0 10 161 12:00 22.8 39 25641 6.4 0 6 161 6:00 17.6 50 20000 6.4 0 7 161 upstream 8 6 160 6250 6.5 0 9 m TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (% dry weight) CONDUCTIVITY (Inkromohs) RESISTIVITY - (Ohm -cm) Ph SULFIDE (ppm) CHLORIDE (ppm) 162 12:00 24.6 55 18182 7.0 0 6 162 6:00 27.7 35 28571 6.8 0 6 162 upstream 37.4 196 5102 6.0 0 11 163 12:00 22.1 63 15873 6.7 0 10 163 upstream 12.5 354 2825 5.2 0 16 164 12:00 43.0 58 17241 7.0 0 14 164 6:00 164 upstream 55.8 178 5618 6.9 0 12 165 12:00 26.1 70 14286 7.3 0 10 165 6:00 165 upstream 44.4 17 58924 6.5 0 4 166 12:00 29.8 90 11111 5.8 0 7 166 6:00 166 upstream 46.2 97 10309 6.4 0 18 167 12:00 25.1 175 5714 7.8 0 12 167 6:00 167 upstream 18.1 115 8696 7.4 0 12 168 12:00 13.0 492 2033 7.6 0 29 168 6:00 168 upstream 22.5 242 4132 7.3 0.122 17 169 12:00 25.7 194 5155 7.9 0 20 169 6:00 169 upstream 9.7 264 3788 7.7 0 15 170 12:00 21.4 353 2833 7.6 0 18 170 6:00 170 upstream 40.4 305 3279 7.3 0.275 26 171 12:00 28.3 195 5128 5.4 0 11 171 6:00 171 upstream 32.6 35 28571 5.7 0 17 172 12:00 26.7 46 21739 5.1 0 6 172 6:00 172 upstream 22.7 9 111111 5.7 0 4 173 12:00 12.9 106 9434 5.6 0 9 173 6:00 28.7 175 5714 5.7 0 30 173 upstream 43.1 116 8621 4.7 0 10 174 12:00 25.6 55 18182 5.4 0 7 174 6:00 174 upstream 16.8 60 16667 5.3 0 7 175 12:00 175 6:00 175 upstream 18.8 77 12987 6.5 0 16 176 12:00 5.4 62 16129 7.5 0 7 176 6:00 9.8 23 43478 6.0 0 7 176 upstream 26.0 54 18519 6.4 0 7 177 12:00 9.5 25 40000 5.7 0 7 177 6:00 29.9 60 16667 6.1 0 7 19 TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (% dry weight) CONDUCTIVITY (miemmohs) RESISTIVITY (ohm -cm) Ph SULFIDE (ppm) CHLORIDE (ppm) 177 upstream 38.5 51 19608 4.8 0 7 178 12:00 27.3 44 22727 5.3 0 7 178 6:00 21.7 125 8000 7.6 0 10 178 upstream 33.4 42 23810 5.9 0 7 200 12:00 7.1 34 29412 4.8 0 4 200 6:00 20.0 130 7692 6.1 0 15 200 upstream 4.2 17 58824 5.0 0 4 201 12:00 8.8 26 38462 5.0 0 7 201 6:00 17.3 32 31250 6.4 0 7 201 upstream 5.3 20 50000 5.3 0 4 202 12:00 7.9 85 11765 4.5 0 6 202 6:00 202 upstream 25.7 381 2625 5.2 0 12 203 12:00 8.5 59 16949 5.9 0 8 203 6:00 43.5 298 3356 7.0 0 58 203 upstream 40.7 177 5650 6.6 0 38 210 12:00 24.7 138 7246 7.7 0 7 210 6:00 40.7 246 4065 7.4 0 9 210 upstream 28.7 160 6250 7.8 0 7 211 12:00 6.8 133 7519 8.0 0 9 211 6:00 29.2 142 7042 8.0 0 16 211 upstream 34.5 244 4098 7.6 0 21 212 12:00 17.4 283 3534 7.9 0 10 212 6:00 47.5 464 2155 7.8 0 10 212 upstream 40.5 336 2976 7.6 0 10 213 12:00 3.8 120 8333 5.8 0 7 213 6:00 21.2 158 6329 7.1 0 11 213 upstream 9.6 156 6410 7.8 0 7 214 12:00 7.6 206 4854 7.8 0 7 214 6:00 52.3 566 1767 7.1 0 14 214 upstream 31.5 197 5076 7.8 0 7 215 12:00 18.7 120 8333 7.4 0 7 215 6:00 215 upstream 28.7 156 6410 7.4 0 10 216 12:00 14.4 50 20000 7.4 0 7 216 6:00 29.6 227 4405 7.4 0 15 216 upstream 43.9 245 4082 7.7 0 16 217 12:00 21.1 130 7692 7.6 0 21 217 6:M 217 upstream 25.9 148 6757 7.9 0 10 218 12:00 15.9 103 9709 7.9 0 7 218 6:00 34.7 134 7463 6.6 0 7 218 upstream 26.3 96 10417 6.5 0 7 219 12:00 8.2 236 4237 7.9 0 9 219 6:00 32.2 394 2538 7.4 0 40 219 upstream 36.4 345 2899 7.5 0 10 20 TABLE 2 (continued) SOIL SAMPLE LABORATORY ANALYSIS FOR ALL SITES SITE LOCATION MOISTURE CONTENT (% dry weight) CONDUCTIVITY (micromohs) RESISTIVITY (ohm -cm) Ph SULFIDE (Ppm) CHLORIDE (Ppm) 220 12:00 8.8 171 5848 7.9 0 7 220 6:00 47.8 168 5952 7.0 0 7 220 upstream 74.9 405 2469 8.8 0.122 13 221 12:00 6.2 131 7634 7.5 0 8 221 6:00 20.8 218 4587 7.8 0 9 221 upstream 10.6 88 11364 7.5 0 7 222 12:00 24.5 272 3676 7.8 0 11 222 6:00 34.9 356 2809 6.9 0 12 222 upstream 25.0 318 3145 7.5 0 11 223 12:00 9.9 227 4405 7.7 0 10 223 6:00 25.8 250 4000 5.8 0 8 223 upstream 17.2 139 7194 7.8 0 10 224 12:00 15.8 68 14706 7.5 0 7 224 6:00 31.4 272 3676 5.6 0 18 224 upstream 35.7 278 3597 7.5 0 7 225 12:00 11.8 536 1866 7.7 0 23 225 6:00 44.6 256 3906 7.2 0 9 225 upstream 39.7 410 2439 7.1 0 11 226 12.00 9.5 87 11494 7.7 0 7 226 6:00 41.8 278 3597 7.0 0 8 226 upstream 33.5 201 4975 7.6 0 10 MAXIMUM 126.8 5244 111111 10.3 12.5 307 MINIMUM 1 9.0 191 4.1 0 1 AVERAGE 22.1 246.0 13838.7 7.2 0.1 23.3 STDDEV 14.5 448.7 17961.6 1.0 0.7 33.8 * Upstream measurements are not immediately adjacent to the pipe. Data is reported only, it is not included in the average service life prediction model data base. 21 Z W O p mOJ N F = H a p w J a a a z m NLL Q J W m LL UN n 0) °D � CV). II II N II II O N S3ldV4VS d0 boamN Kai 22 F- Z W Z O Z O U m LU W cm H x w N rn U Z W O W Qd LL W 2 Ma LL N J O N S31dWdS d0 a3evynN 0 0 m 0 rn 00 ro 0 ro Ln - 2 0 o LU LO cc N } o 0 LL u O � W o j co L O a o Z n W � V 0 W "' a N 23 z O S m a N W CO W S N d N C C7 V N S W O w O U. O N w LL 0 0 0 0 0 0 0 0 0 0 o) oo n a n N SYMMS 30 d3GvgnN Ln cc co 2 a Ln Lq a ri 24 Z O H >_ � F- m N 2 N UJ M C ' LU w Q D y o _J LU 2 O LL N N W H N J J Q O LL O O O O O d f� ry S3ldWdS d0 E139vynN 0 0 0 0 0 O 0 0 0 rn 0 0 0 0 ro 0 0 0 0 o o U o 2 0 0 o 0 0 H co 0 � 0 W CC O 7 D D 7 7 N D D D 7 J J D 25 TABLE 3 DATA USED TO PERFORM STATISTICAL CATEGORICAL ANALYSIS ON PLAIN GALVANIZED EXTERIOR PIPES SITE LOCATION MOISTURE (% DRY WT.) RESISTIVITY (OHM -CM) pH CHLORIDES (PPM) AGE (YRS.) GALV REMAINING (%) POTENTIAL (VOLTS) 6 4:00 21.0 9174 8.2 42 41 100.0 928 6 8:00 21.2 5917 7.8 71 41 100.0 999 6 12:00 13.2 3906 6.6 42 41 100.0 966 7 4:00 20.6 9615 6.9 37 39 0.0 275 7 8:00 21.9 14084 6.4 41 39 0.0 561 7 12:00 33.3 5263 7.3 48 39 0.0 678 22 4:00 27.4 7634 7.6 11 27 100.0 1016 22 8:00 20.0 17241 8.4 7 27 98.0 996 22 12:00 11.8 16129 8.4 9 27 100.0 997 43 8:00 5.8 12658 8.7 6 73 90.0 925 44 4:00 14.6 4184 8.6 30 73 50.0 348 44 8:00 20.4 4830 8.4 12 73 0.0 252 44 12:00 12.3 1326 9.1 175 73 50.0 440 53 4:00 11.2 10526 8.3 3 31 100.0 952 53 8:00 8.8 14492 8.7 6 31 100.0 909 54 4:00 4.4 3205 8.1 5 30 100.0 1047 54 8:00 9.0 17241 8.3 5 30 100.0 1030 56 4:00 16.6 4694 9.7 9 52 100.0 1102 56 8:00 11.2 3546 10.3 13 52 100.0 1002 56 12:00 12.9 10204 8.1 7 52 100.0 1002 57 4:00 25.3 5076 8.4 14 73 0.0 395 57 8:00 29.1 2403 8.6 30 73 0.0 392 58 4:00 24.1 2222 8.5 62 73 0.0 372 58 8:00 16.7 1623 8.2 77 73 0.0 332 58 12:00 10.7 1848 8.6 46 73 0.0 405 60 4:00 11.9 27027 7.1 3 50 0.0 672 60 8:00 11.0 50000 6.9 2 50 0.0 448 60 12:00 12.7 47619 6.5 5 50 0.0 543 65 12:00 16.8 40000 5.6 1 51 0.0 294 66 4:00 21.4 8403 7.4 3 37 100.0 995 66 8:00 33.9 7142 7.3 4 37 100.0 896 66 12:00 11.9 14925 7.7 3 37 100.0 893 67 4:00 23.5 8130 7.5 10 38 100.0 471 67 8:00 23.7 5586 7.3 8 38 100.0 466 67 12:00 21.3 14084 7.5 4 38 100.0 440 68 4:00 13.9 11764 8.0 15 37 100.0 932 68 8:00 12.6 11494 8.0 5 37 100.0 832 68 12:00 15.2 31250 7.9 3 37 100.0 525 69 4:00 37.1 7352 7.6 8 37 100.0 723 69 8:00 28.3 8620 7.7 9 37 100.0 821 69 12:00 19.0 10416 8.2 4 37 100.0 827 71 4:00 36.0 20408 6.6 4 48 100.0 328 71 8:00 23.0 13513 6.5 3 48 100.0 504 77 4:00 7.0 76923 7.3 2 40 90.0 794 77 8:00 12.2 66666 7.6 3 40 100.0 842 9.1 TABLE 3 (continued) DATA USED TO PERFORM STATISTICAL CATEGORICAL ANALYSIS ON PLAIN GALVANIZED EXTERIOR PIPES SITE LOCATION MOISTURE (% DRY WT.) RESISTIVITY (OHM -CM) pH CHLORIDES (PPM) AGE (YRS.) GALV REMAINING POTENTIAL (VOLTS) 77 12:00 2.4 13698 6.9 4 40 100.0 986 80 4:00 20.8 4830 7.0 39 54 100.0 342 80 8:00 19.3 4878 7.0 37 54 100.0 421 80 12:00 9.8 3891 7.4 65 54 80.0 749 101 4:00 22.9 2294 7.2 55 62 11.8 598 101 8:00 20.4 2833 7.9 75 62 50.0 569 101 12:00 18.0 1742 8.1 34 62 93.4 578 104 4:00 16.1 22727 5.7 12 51 10.4 495 104 8:00 11.1 13699 8.1 12 51 10.4 625 104 12:00 8.5 9091 8.0 21 51 100.0 776 105 12:00 12.9 13158 6.6 16 57 100.0 1026 106 4:00 37.9 8929 7.0 40 53 6.6 346 106 12:00 5.0 29412 7.4 12 53 100.0 1069 115 12:00 3.9 1276 6.9 100 27 100.0 989 116 4:00 9.8 1916 7.4 35 36 100.0 780 116 8:00 32.0 1346 7.3 52 36 0.0 434 116 12:00 4.7 678 7.0 24 36 5.0 377 117 4:00 37.3 3610 7.8 9 41 37.5 364 117 8:00 28.5 2786 7.4 16 41 4.2 518 117 12:00 23.4 3257 7.6 9 41 100.0 809 118 4:00 23.7 4065 7.4 5 40 100.0 917 118 8:00 11.9 3012 7.4 7 40 100 805 119 12:00 1.7 7353 7.5 15 52 89.0 980 120 4:00 9.5 7937 7.6 64 36 77.0 888 120 8:00 11.8 8929 7.6 32 36 66.0 704 120 12:00 1.3 4902 7.1 33 36 100.0 1020 131 4:00 15.0 2577 8.7 65 54 0.0 412 131 8:00 16.9 1919 8.5 49 54 0.0 329 131 12:00 12.8 2404 9.0 47 54 0.0 315 150 4:00 10.0 26316 7.6 23 33 100.0 993 150 8:00 8.0 37037 7.2 12 33 100.0 767 150 12:00 12.0 3597 6.8 44 33 100.0 1021 151 4:00 13.0 5952 8.5 12 31 0.0 577 151 8:00 16.8 3937 8.1 19 31 0.0 620 151 12:00 12.0 8696 8.7 12 31 100.0 846 152 4:00 6.0 5208 9.4 20 48 100.0 740 152 8:00 13.6 9174 8.4 10 48 95.8 756 152 12:00 11.7 8929 8.6 21 48 100.0 806 153 4:00 20.4 6667 8.0 21 19 84.0 692 153 8:00 19.5 4405 7.5 32 19 81.3 729 153 12:00 20.3 6667 7.9 110 19 100.0 1012 154 4:00 8.7 10989 8.8 15 16 100.0 1024 154 8:00 5.5 6757 8.4 27 16 100.0 1034 27 TABLE 3 (continued) DATA USED TO PERFORM STATISTICAL CATEGORICAL ANALYSIS ON PLAIN GALVANIZED EXTERIOR PIPES SITE LOCATION MOISTURE (% DRY WT.) RESISTIVITY (OHM -CM) pH CHLORIDES (PPM) AGE (YRS.) GALV REMAINING POTENTIAL (VOLTS) 154 12:00 3.0 10000 8.7 18 16 100.0 1013 160 6:00 56.0 7634 7.0 33 53 81.0 915 160 12:00 24.6 14706 7.4 9 53 5.0 405 161 6:00 17.6 20000 6.4 7 53 0.0 354 161 12:00 22.8 25641 6.4 6 53 0.0 520 162 6:00 27.7 28571 6.8 6 53 95.0 1060 163 12:00 22.1 15873 6.7 10 53 0.0 315 164 6:00 53 0.0 407 164 12:00 43.0 17241 7.0 14 53 100.0 377 165 6:00 53 0.0 355 165 12:00 26.1 14286 7.3 10 53 0.0 365 166 6:00 11 100.0 1125 166 12:00 29.8 11111 5.8 7 11 97.0 1120 167 6:00 16 46.0 859 167 12:00 25.1 5714 7.8 12 16 100.0 1091 168 6:00 21 88.0 970 168 12:00 13.0 2033 7.6 29 21 98.0 1100 169 6:00 7 62.0 942 169 12:00 25.7 5155 7.9 20 7 100.0 1120 170 6:00 19 0.0 403 170 12:00 21.4 2833 7.6 18 19 100.0 1120 171 12:00 28.3 5128 5.4 11 21 100.0 1101 172 6:00 11 15.0 400 172 12:00 26.7 21739 5.1 6 11 100.0 1100 173 6:00 28.7 5714 5.7 30 41 3.0 530 173 12:00 12.9 9434 5.6 9 41 21.0 445 174 12:00 25.6 18182 5.4 7 9 85.0 833 175 6:00 17 98.0 677 175 12:00 17 100.0 912 176 6:00 9.8 43478 6.0 7 10 54.0 1080 176 12:00 5.4 16129 7.5 7 10 4.0 1060 177 6:00 29.9 16667 6.1 7 8 0.0 470 177 12:00 9.5 40000 5.7 7 8 100.0 1117 178 6:00 21.7 8000 7.6 10 54 0.0 430 178 12:00 27.3 22727 5.3 7 54 0.0 486 200 6:00 20.0 7692 6.1 15 25 0.0 366 200 12:00 7.1 29412 4.8 4 25 0.0 406 201 6:00 17.3 31250 6.4 7 25 0.0 508 201 12:00 8.8 38462 5.0 7 25 54.0 1006 202 6:00 33 0.0 490 202 12:00 7.9 11765 4.5 6 33 31.0 738 203 6:00 43.5 3356 7.0 58 25 0.0 330 203 12:00 8.5 16949 5.9 8 25 25.0 558 210 6:00 40.7 4065 7.4 9 22 10.0 498 210 12:00 24.7 7246 7.7 7 22 100.0 1110 TABLE 3 (continued) DATA USED TO PERFORM STATISTICAL CATEGORICAL ANALYSIS ON PLAIN GALVANIZED EXTERIOR PIPES SITE LOCATION MOISTURE (96 DRY WT.) RESISTIVITY (OHM -CM) pH CHLORIDES (pPM) AGE (YRS.) GALV REMAINING M POTENTIAL (VOLTS) 211 6:00 29.2 7042 8.0 16 20 100.0 1111 211 12:00 6.8 7519 8.0 9 20 98.0 1106 212 6:00 47.5 2155 7.8 10 12 100.0 867 212 12:00 17.4 3534 7.9 10 12 100.0 1097 213 6:00 21.2 6329 7.1 11 29 98.0 678 213 12:00 3.8 8333 5.8 7 29 100.0 1060 214 6:00 52.3 1767 7.1 14 41 100.0 1122 214 12-00 7.6 4854 7.8 7 41 100.0 1125 215 6:00 21 10.0 495 215 12:00 18.7 8333 7.4 7 21 100.0 535 216 6:00 29.6 4405 7.4 15 18 99.0 1067 216 12:00 14.4 20000 7.4 7 18 100.0 1073 218 6:00 34.7 7463 6.6 7 15 5.0 404 218 12:00 15.9 9709 7.9 7 15 98.0 1010 219 6:00 32.2 2538 7.4 40 25 8.0 497 219 12:00 8.2 4237 7.9 9 25 100.0 1049 220 6:00 47.8 5952 7.0 7 18 62.0 1004 220 12:00 8.8 5848 7.9 7 18 100.0 1083 221 6:00 20.8 4587 7.8 9 25 10.0 458 221 12:00 6.2 7634 7.5 8 25 100.0 1062 222 6:00 34.9 2809 6.9 12 19 0.0 531 222 12:00 24.5 3676 7.8 11 19 73.0 856 223 6:00 25.8 4000 5.8 8 21 0.0 493 223 12:00 9.9 4405 7.7 10 21 100.0 1117 224 6:00 31.4 3676 5.6 18 21 545 224 12:00 15.8 14706 7.5 7 21 97.0 1055 225 6:00 44.6 3906 7.2 9 15 10.0 404 225 12:00 11.8 1866 7.7 23 15 100.0 1040 226 6:00 41.8 3597 7.0 8 18 92.0 1086 226 12:00 9.5 11494 7.7 7 18 98.0 1016 29 w a a. w� cr cc O w N LO Z QQQ (7 O Z_ Q J CL O w Q 0 U_ w cc IL J Z J O w Fo LU ir U cc 0 O w U N a: Z O j Fr J LL LLJ O O Z O LLLL Q w X J � Q J > ltl cn Ir w r O N U O O O O O O O O O O O O O O O O (SHV3,k) 30V a310Ia3ad w U Q Fw- U 0 w cr d LL O cc w 0 ir Z 0 Z w U CO Z LW a Ln N x C) 0 N V a EL d L 3 aD Q Ln N V N CL CL a� i 0I Q x N n LLl LL- w U LU LLJ LLI PO 30 z 0 z 0 0 z m UCIO W U) on Wir w N —>j 0 < cr (D LL Z w cr CL LL w (L E-L LLJ 0 O o o 0 0 LO 0 0 Ln (SHV3,k) 30V 4310103did O CD 31 W a d 0 4W V O w N r" Z d J a Z Q J IL W LLI U_ 0 W cc a J Z O Z O Fn O _O cc LU cc LL W cc D J L¢L. rn Ir O U) U U O O O O O O O O O O O O O O O 00 h l0 UC C n N (SUVRO 30V 0310103dd a� cm T x C, O N V N a n m d L 3 d Q LO CM N V N d + d d d L 3 G7 a X N 11 W U- J LL 0 w w a� w a 32 Er LO } O T Z Q 2 CO J W (13 0 w U_ m 2 � (L W Lr a ir W 2 n 2 d 0 U. O f] W J R n J Z O Z O U—)� 0a lr � OW UL tr Om. R Q t0 Q Z 20 OQ Lr LL J W Q Lr > � LLI J Q LL W a a Q w r 0 CD o N `o o m > > °' o N o OL c E o o o N 0 o M w N - O O Q) 0 V O Q) Ln a O O Ln o O Ln (SdV3,k) 30d a3131a38d OTA N LL d Q+ Wa H � U � W 3 jr m a LL O + Lr W N Lr V a N Z d Q + Wa CO Q Z 3 rn m W a C (n x CV II 33 TABLE 4 PRESS ALT & V TO ENTER DATA. PRESS F10 TO VIEW GRAPH. PRESS ALT & P TO PRINT DATA. AGE OF AVERAGE SERVICE LIFE = 69.4 YEARS RESISTIVITY (OHM -CM) 5000 PH 7 CHLORIDE (PPM) (% 42 MOISTURE SATURATED) 35.5 100% 80% 20% 0% GRAPH 9 NCSPA STUDY CONDITION OF GALVANIZED COATING AGE = 69.4 CHLORIDE = 42 PH = 7 % MOISTURE = 35.5 RESISTIVITY = 5000 i 50 AGE (YEARS) m AVERAGE USEFUL SERVICE LIFE: 2 X (P1+P2<25 + (P1+P2<20%) X 12.5%) 150 34 O O (D O O O oo to N lOV1NI E)NIIVOO 09ZINVAIVD 1N3OH3d I 35 COMPUTER MODEL AVERAGE SERVICE LIFE SOIL SIDE ANALYSIS The computer model is based on Warren Rogers's statistical model to predict the Average Service Life of plain galvanized steel pipe based on exterior corrosion. AVERAGE SERVICE LIFE _ 2 x UAGE WHERE P1 +P2 < 25%) + (AGE WHERE P1 +P2 < 20%) x 12.51 The following variables from the soil sample will be entered into the computer model to calculate the average service life of the pipe: Variable Resistivity pH Chloride Moisture Content Unit of Measure ohm -cm xx.xx ppm Percent Saturated The program will calculate the Average Service Life of the pipe as shown in Table 4 and generate a screen graph as shown in Graph 9. A backup copy of the program disk should be made first by using the DOS command Diskcopy Diskcopy drivel: drive2: where: Drivel is the source drive Drivel is the target drive Diskcopy prompts you to insert the source and target disks at appropriate times and waits for you to press any key before continuing. After the backup copy is made, store the original and use the backup copy to run the program. INSTRUCTIONS: To load the program: Once the computer is on, place the backup copy of the NCSPA Program Disk in Drive A and enter A: then enter AGE, the baled program screen will look like the printout in Table 4. To enter soil data: Once the screen format is like that shown in Table 4, pressing the <ALT> and V keys at the same time you will be prompted to enter the soil sample data for Resistivity, pH, Chloride and Moisture Content. P.O. Box 1504 LA Qvivre, CALIFORNIA 92247-1504 78-495 CALIJ', FAMPIC0 LA QuiNrA, CAIIF0RNIA 92253 August 25, 2006 Mr. Jack Tarr Washington 111 LTD. 3n2.1•:! Rancho Vio•'o Road, Suit,-- B San Juan Capistrano, CA 92675 Re: Underground Retention for Washington Park Dear Mr. Tarr: (760) 777-7000 FAX (760) 777-7101 AUS 2 4 2406 The meeting that you requested about underground retention was held at the City on Thursday, August 3, 2006. It was acknowledged by everyone at the meeting that the intended application for the underground storage was beneath a parking lot for a commercial development. It was also acknowledged that failure of the structure could result in the collapse of the parking lot. This structural collapse could affect adjacent buildings, cause economic loss to both tenants and the City, and/or cause citizen injury. In this event, the entire retention facility and parking lot would have to be reconstructed. It was also acknowledged by everyone at the meeting that a concrete underground structure would have a longer service life than a metal underground structure under identical conditions. It is a common practice in engineering to evaluate alternative materials, especially if there are cost differences. A cost analysis provided by your consultant, Steve Speer, shows that a concrete structure would cost about $462, 000 while the equivalent metal structure would cost only $257,650. The difference in cost is $204,350. Given this particular application (underground retention below a parking lot), and the potential adverse ramifications to the health, safety and welfare of citizens due to failure of the system, the Public Works department believes that it is in everyone's best interest to use the concrete system for this project. Nothing that was presented at your meeting of August 3, leads me to believe that this conclusion is not correct. G:\Genovese, T\letters\Tarr, Jack re Underground Retention 08-25-2006.doe At the meeting, you asked for background information on how the City arrived at the 36 hour max retention time standard for underground retention as promulgated in the draft policy. Due to our limited experience with underground retention, my staff attempted to advance a reasonable standard that is accepted in other jurisdictions. The 36 hour max retention time standard is required by many local Arizona jurisdictions including Phoenix, Scottsdale, Tempe and Tucson. Additionally, the 36 hour max retention time standard is required by the Maricopa County Health Department (pest control requirement). Lastly, you expressed concern that Coachella Valley Water District staff may not be prepared to grant approval on deep dry wells. My staff has liaised with CVWD staff on this issue and is confident that CVWD will not delay approval of Maxwell or equivalent systems. These systems have already been approved by CVWD and have been physically installed on several projects in La Quinta. If you have any questions regarding this matter, please feel free to contact Tim Jonasson, Public Works Director/City Engineer, at (760) 770-7042 or Ed Wimmer, Principal Engineer, at (760) 777-7088. Sincerely, Thomas P. Genovese City Manager TRJ/EJW/cd c: Tim Jonasson, Public Works Director/City Engineer Ed Wimmer, Principal Engineer Paul Goble, Senior Engineer File G:\Genovese, T\letters\Tarr, Jack re Underground Retention 08-25-2006.doc WASHINGTON III, LTD 80618 DECLARATION AVE. RECEIVED INDIC), CA 92201 CITY OF I_A CUIfdTA September 8, 2006 CI' v CLFF,�'„ O,=FICE Mr. Tim Jonasson Public Works Director/City Engineer Mr. Tom Hartung Director of Building & Safety Ms. June S. Greek City Clerk City of La Quinta 78-495 Calle Tampico La Quinta, California 92253 760-775-7967 Phone 760-775-8329 Fax RE: Appeal of Decision of Director of Public Works (on Behalf of the Building and Safety Department) and Appeal of the Decision of the City Manager Concerning La Quinta Staff Discretionary Policies Regarding Suitability of Alternate Materials and Methods of Installation for Underground Retention Facility as applied to the Washington Park Development To Whom It May Concern: Washington 111, Ltd has been attempting to resolve the La Quinta requirements for a passive `open bottom' on -site private underground retention chamber for receipt of on -site storm water for a number of months so they can proceed with the completion of their precise grading plans and obtain a permit accordingly. Instead, they have received conflicting, unsupported and inappropriate interpretations of policy which has not been reviewed or approved by the City Council. While this appeal is for the project, Washington Park, it focuses on issues of concern to the entire commercial development community within the City. Mr. Tarr sets forth all of the following grounds for appeal. 1. The proposed 5 gauge multi -plate zinc coated structural steel passive retention facility is structurally sound and not subject to collapse Washington 111, Ltd, has submitted information regarding the multi -plate five gauge zinc coated structural steel open bottom passive retention chamber which they City of La Quinta Re: Appeal of Rejection of Retention Alternative September 8, 2006 Page 2 proposed to use, but was told by the City — without any factual support — that it was subject to "collapse" and that, therefore, a concrete structure had to be used. City staff repeatedly failed to consider the engineering submittals from Comech, Inc. and Parsons Engineering regarding underground steel structures. 2. The requirement for a drywell system to obtain a 36 hour maximum retention time is unnecessary and inannrooriate given local vector control suggested parameters. Washington 111, Ltd also raised concerns regarding the discretionary requirement for a 36 hour maximum retention time and a drywell system. The Director's requirement of a drywell system to achieve a 36 hour maximum retention time is purportedly based on a 36 hour time period imposed by cities in Arizona and purportedly required by Maricopa County Health Department for vector control. There is no scientific basis suggesting that the 36 hour time period imposed by Arizona cities is necessary for vector control or other health reasons in the City of La Quinta. Please also note that the cities in Arizona have no prohibition against use of alternate materials for retention chambers including zinc coated multi -plate structural steel. 3. Draft Underground Retention Basin Design Requirements dated June 29, 2006 The Engineering Standards utilized by the Public Works staff to condition underground retention basins in commercial centers are an abuse of administrative discretion and are without support on engineering or health and safety grounds. Specifically, Washington 111, Ltd challenges Engineering Standards as set out in the June 29, 2006, Draft Underground Retention Basin Design Requirements (which, although "draft" have been applied for over a year) as well as the discretionary administrative interpretations of such policies, including #97-03. The Director's rejection of the zinc coated structural steel system and requirement for the drywell system are based solely on adherence to particular building and construction standards set forth in a new draft Engineering Bulletin posted on June 29, 2006. We would respectfully submit that those particular building and construction standards should have been submitted for City Council and public review as an ordinance amending Title 8 of the City's Municipal Code. The particular standards and the Director's strict adherence to them are apparently intended solely to counter Washington 111, Ltd's alternative proposal and are without scientific support. The Director's strict adherence to particular draft Bulletin standards is even contrary to the standards themselves. For example, the Bulletin expressly allows use of an "approved equal" to reinforced concrete vault style systems. Please note there is no minimum design service life criteria established for achieving an "or equal" status. Also, the Bulletin does not expressly require drywell systems except as needed to address City of La Quinta Re: Appeal of Rejection of Retention Alternative September 8, 2006 Page 3 standing, stagnant water and vector control systems. For perforated systems, the Bulletin also expressly states that drywell systems should be approached as an "at risk" design subject to Coachella Valley Water District approval. 4. City staff has failed and refused to consider obiective enizineeriniz and related information provided to them to support the request for an alternative system. Contech, Inc. manufactures both the Department approved and installed concrete system (which does not adhere to a 36 hour draw down time standard) and the proposed steel system. During an August 3, 2006 meeting between the Director, City Manager and Washington 111, Ltd. representatives, a Contech representative verified that the proposed zinc coated structural steel system has a design service life equal to or greater than the Director approved concrete system. In addition, a structural engineer from Parson's Engineering did an independent study of metal systems and found that the systems were structurally sound. In addition, the proposed product exceeds the minimum required design service life criteria for the product category established by the Army Corp of Engineers, the United States Department of Transportation Federal Highway Administration and the California Department of Transportation (CalTrans). All of these agencies including the American Association of State and Highway Transportation Officials (AASHTO) allow the proposed product and encourage diversity in choice of materials for engineering solutions. The Director does not have internal or independent structural engineering analysis that contradicts the conclusions of Parsons and Contech. Instead, the Director bases his decision upon the unfounded fear that the system could collapse and cause damage to property and life because the system will be located beneath a parking lot. The Director presents no analysis that the risk of collapse is significant for a steel structure or that the risk of collapse would be significantly lessened with a concrete structure. The Director presents no analysis of whether the significant additional cost for a concrete structure will provide any significant public safety benefits. After raising all of these issues, and repeatedly meeting with staff and the City Manager in an effort to resolve them, on August 29, 2006, Washington 111, Ltd's General Partner, Mr. Tarr received a letter from Thomas Genovese, City Manager, advising Mr. Tarr of a decision by Tim Jonasson, Director of Public Works, to reject Mr. Tarr's proposed use of alternate materials and methods of installation for an underground retention facility. The Director's decision was made on behalf of the City's Department of Building and Safety pursuant to Section 8.70.100(B) of the City's Municipal Code. Washington 111, Ltd. hereby appeals that decision pursuant to La Quinta Municipal Code Section 8.01.030(B). Mr. Genovese also rejected Washington 111, Ltd.'s request (and mischaracterized the meeting regarding that request); because of that and the application 3 City of La Quinta Re: Appeal of Rejection of Retention Alternative September 8, 2006 Page 4 of discretionary Engineering Standards and policies, we also appeal alternatively pursuant to La Quinta Municipal Code Section 2.04.100. For the foregoing reasons, Washington 111, Ltd. respectfully requests a hearing before the appropriate City body to consider the merits of this appeal. The amount of the fee included here is the amount stated to us by the City Clerk's office. Thank you for your consideration of this matter. Sincerely, Jack Tarr General Partner Washington 111, Ltd Enclosure: $175 Filing Fee Cc: McCormick, Kidman & Behrens City Council 4 P.O. Box 1504 78-495 CALLE TAMPICO LA QUINTA, CALIFORNIA 92253 October 19, 2006 Mr. Jack Tarr Washington 111, LTD 80618 Declaration Avenue Indio, CA 92675 BUILDING & SAFETY DEPARTMENT (760) 777-7012 FAX (760) 777-7011 RE: Appeal of the Decision of the City Manager concerning La Quinta Staff discretionary policies regarding the suitability of alternate materials and methods of installation for an underground retention facility as applied to the Washington Park development. Dear Mr. Tarr: A hearing before the Board of Appeals for the above matter has been set for October 31, 2006 at 2 PM in the City Hall Session Room. Please provide to the Building and Safety Department five (5) copies of any materials that you would like the Board to review prior to the hearing. I will need said materials no later than October 26, 2006, in order for them to be included in the packets provided to the Board Members. If you have any questions please feel free to contact me at 777-7019. 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NMI 22t :bdSq ----------------- 4 u zi i Sladden Engineering 6782 Stanton Ave., Suite A. Buena Park, CA 90621 (562) 864-4121 (714) 523-0952 Fax (714) 523-1369 39-725 Garand Ln_, Suite G. Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895 August 28, 2002 Project No. 544-2106 02 08-485 Washington I 11, LTD. c/o Dale Frank Associates 7825 Southeast 76th Street Mercer Island, Washington 98040 Attention: Mr. Dale Frank Project: Proposed Target Store & Surrounding Retail Center Highway I 1 I Between Adams Street and Washington Street La Quinta, California Subject: GeotechnicalInvestigation Presented herewith is the report of our Geotechnical Investig Target Store and surroundingation conducted at the site of [he proposed mixed use commercial development to be located on the south side of Ilighway I I I between Adams Street and Washington Street in the Cite of La Quinta, California. The investigation was performed in order to provide recommendations for site preparation and to assist in foundation design for the proposed Target Store as well as the associated retailiconunercial structures and the related site improvements. This report presents the results of our field investigation and Iaborator, testing along with conclusions and recommendations for foundation design and site preparation. This report completes our oriinal scope of services as outlined within our proposal dated June 26, 2002. g We appreciate the opportunity to provide service to you on this project. If you have any questions regarding this report, please contact the undersigned Respectfully submitted, SLADDEN ENGINEEI Brett L. Anderson Principal Engineer S ER/pc Copies: - 6/Dale Frank & Associates Pl..,/.l__ c tlr/L7/cUu[ CJ7: V1 riVJ4 J1OVr WWVIClrI �C J� LH�J ANAHEYM TEST LABORATORY 3002 S- ORANGE AVENUE - SANTA ANA_ CALIFORNIA 92707 PHONE (714) 549-7267 - T0: SLADDEN ENGINEERING: 6782 STANTON AVE. SUITE E BUENA PARK, CA. 90621 ATTN: BRETT/DAVE PROJECT: #544-2106 BULK 3 @ 0-5' ANALYTICAL REPORT CORROSION SERIES SUMMARY OF DATA ru.� tli I w1F_ 7/29/02 ro.No. Chain of Custody $Nppm No, lab.No. A-1728 1AoWml. SOIL pH SOLUBLE SULFATES SOLUBLE CHLORIDES MIN. RESISTIVITY per Ca. 417 per Ca. 422 per Ca. 643 ppm ppm ohm -cm 7.2 440 148 730 LY RESPE it POPPY cbmf rain ' ANAHEIM TEST LABORATORY 3008 S. ORANGE AVENUE SANTA ANA, CALIFORNIA 92707 PHONE (714) 549-7267 O: SLADDEW ENGINEERING: 6782 STANTON AVE. SUITE E BUENA PARK, CA. 90621 ATTN: BRETT/DAVE PROJECT: #544-2106 BULK B @ 0-5- ANALYTICAL REPORT CORROSION SERIES SUMMARY OF DATA DATE: 7/23/02 FO.No. Chain of Custody Stupper No. - Lab. No. A-1702 Specification: mcenaL SOIL pH SOLUBLE SULFATES SOLUBLE CHLORIDES MIN. RESISTIVITY per Ca. 417 per Ca. 422 per Ca. 643 ppm - ppm ohm -cm 7.5 49 OW .2 630 1,533 y IMEMBER i1OG IN .r Password Log In ® animations ask Dr. Galy ® corrosion educational seminars ® fabricator CD D literature ® published articles ® specifier CD -corrosion performance -costleconomics -the HDG coating -related specifications -ASTM standards -sustainable development -zinc metal facts ® specifier newsletter ® techforum Quicrt LrNKs d GAU' ANIZER ` .11 LGCAFEd 51I65CRIPTEON CONTINUING EDUCATION iy '1 technical info: specifier CD: corrosion performance: corrosion data: corrosion i.Y data cunt corrosion data continued... Corrosion of Zinc -Coated Steel in Seawater Corrosion of Zinc -Coated Steel in Various Industrial and Domestic_ Waters National Corrugate Steel Pipe_Assoaatlon_Ch_art Corrosion of Galvanized Steel Pipe in Contact with Soils in the United States CORROSION OF ZINC AND ZINC -COATED STEEL IN SEA WATER Location and water Type of zinc Type of test Years Agitation Corrosion rat. (WWyear) Eastport, Maine 99.1%zinc Mean tide level 3 25 Seawater Eastport, Maine 99_1%zinc Immersion 3 16 Seawater Bristol Channel Immersion Seawater Prime Western about 93%of 4 91 Bristol Channel Seawater Southhampton docks Seawater Southhampton docks Seawater Southhampton docks Seawater Fort Amador, Canal Zone Tropical, Pacific Ocean Fort Amador, Canal Zone Tropical, Pacific Ocean Fort Amador, Canal Zone Tropical, Pacific Ocean Fort Amador, Canal Zone Tropical, Pacific Ocean Panama Seawater Panama Seawater time Immersion Galvanzied bar about 93% of time Prime western At half-tide level High grade At half-tide level Galvanized I mmersion plate Intermediate Immersion Intermediate Immersion Intermediate Mean tide level Intermediate Mean tide Cast -Prime Immersion Western Cast -Special Immersion 4 3 3 1 4 0.15 m/s Flow 8 0.15 m/s Flow 4 0.15 m/s Sow 8 0.15 m/s Flow 1 1 64 13 14 28 20 16 23 14 25 25 http://www.galvanizeit.org/showContent,305,349.cfm 10/24/2006 van^ous Uata on Corrosion Page 2 of 4 DESIGN CD high grade Kure Beach, North Special high Immersion 0.5 Flowing 48 .r^") PROJECT Carolina Seawater grade Lt DATA ASE Kure Beach, North Special high Immersion 4 Flowing 20 Carolina Seawater grade ACADEMIC Kure Beach, North SCHOLARsaIa Carolina Seawater Brass special Immersion 0.5 Flowing 48 6 Kure Beach, North Carolina Seawater grass special Immersion 4 Flowing 18 Kure Beach, North Galvanized Immersion 0.5 Flowing 48 Carolina Seawater Kure Beach, North Galvanized Immersion 1 Flowing 23 Carolina Seawater Kure Beach, North Carolina Seawater Galvanized Immersion 3.5 Flowing 15 Kure Beach, North Galvanized Immersion 5 Flowing 13 Carolina Seawater Gosport and Emsworth Hot -dipped Immersion 6 Flowing 9 Seawater Gosport and Emsworth Hot -dipped Immersion 6 Flowing 9 Seawater Gosport and Emsworth Cyanide, Immersion 6 Flowing 8 Seawater electrodeposil Gosport and Emsworth Sprayed, Seawater molten metal Immersion 6 Flowing 4 pistol Gosport and Emsworth Sprayed, Immersion 6 Flowing 17 Seawater powder pistol Gosport and Emsworth Sprayed, wire Immersion 6 Flowing 6 Seawater pistol Source: Porter, F. C. Corrosion Resistance of Zinc and Zinc Alloys. Dekker, New York, 523pp. 1994. A back to top CORROSION OF ZINC AND ZINC COATINGS IMMERSED IN VARIOUS INDUSTRIAL AND DOMESTIC WATERS Type of water Corrosion Rate (µnVyr) Mine water, pH 8.3, 100 ppm hardness, aerated 31 Mine water, 160 ppm hardness, aerated 30 Mine water, 110 ppm hardness, aerated 46 Demineralized water 137 River water, moderate soft 61 River water, treated by chlorination and copper 64 sulfate Tap water, pH 5.6, 170 ppm hardness, aerated 142 Spray cooling water, chromate treated, aerated 15 Hard water 16 Soft water 15 http://www.galvanizeit.org/showContent,305,349.cfm 10/24/2006 9 g fWjiii .,Aid WHO I R Mw oi " a Qje Z z So All . 111211 : , A' ' 1A1Aj �11 h xxx a 11 Apr AAA i M BA MA3, I munnus .1, A i!� hWu Sw =am 2 am mail may a mappq Maness =54a =22;; 9111 110% 8 A 8A-' RRRR 8 ......00Oo ease R. jj I al Various Data on Corrosion Page 3 of Sources: Defrancq, J. N. ;Zinc and zinc -lead alloys in domestic water, Br. Corros. J. 17, 125-130, 1982. Slunder, C. J., and Boyd, W. K.; Zinc: Its Corrosion Resistance, 2nd ed., International Lead Zinc Resean Organization, Inc., New York, 1986. Aback. to top National Corrugate Steel Pipe Association Chart To provide quick reference to coating selection on corrugated steel pipe, the National Corrugated Steel Pi Association has produced the following chart. Contained in the chart is the anticipated service life of galvanized coatings based on soil pH and resistivity. This chart is applicable to all uses of hot -dip galvanic steel in soil and can be used as a guide to anticipate its service life in soil. To view the complete report vis htto://www.ncsoa.orglgdf/tech durabilityguide.pdf. i If 'I'' 1'• 0111'll�'121111;i MPP,iFil� P�� I''I�/I O' PPOP �w,II1A'�pow PA, co too I.Wo 1o.W9 100,= RrsW" IRI. abm vans • 15 e5 i,L410R tM fo (21 W2440 top to 4H)I This chart. created by the National Corrugated Steel Pipe Association, predicts corro- sion of galvanized steal buried in soil based on the resistivity and pH of the soil. A back to top CORROSION OF GALVANIZED STEEL PIPE IN CONTACT WITH A VARIETY OF SOILS IN THE UNITED STATES Weight loss (glm2)a and maximum pit depth (mm) after burial for years stated Loss Loss Loss Loss Soil Type after Maximum after Maximum after Maximum after Maxim 2.1 pit depth 4.0 pit depth 9.0 pit depth 12.7 pit del years years years years Inorganic oxidizing acid soils Cecil clay loam 90 0.23 430 0.15 180 <0.15 180 < Hagerstown loam 90 <0.15 300 02 210 0.15 180 <( Susquehanna clay 300 0.23 700 0.23 270 <0.15 240 <( Inorganic oxidizing alkaline soils Chino silt loam 330 <0.15 700 0.15 490 <0.15 330 < Mojave fine gravelly 480 0.15 1000 0.2 330 <0.15 330 <C loam Inorganic reducing acid, soils http://www.galvanizeit.org/showContent,305,349.cftn 10/24/2006 Various Data on Corrosion Page 4 of 4 , Sharkey clay 180 0.15 460 0.3 210 <0.15 330 C Acadia clay 1000 0.15 1460 0.2 Inorganic reducing alkaline soils Docas clay 980 0.2 490 0.23 490 0.25 490 <( merced silt loam 640 0.2 130 0.3 30 0.15 400 Lake Charles clay 1130 0.13 1190 0.18 1680 0.33 4210 1 Organic reducing acid soils Carlisle muck 360 0.2 1040 0.28 915 0.2 1040 <( Tidal marsh 360 <0.15 640 0.25 610 0.2 1460 1 Muck 1310 0.33 1650 0.53 2750 1.63 3260 1 Rifle peat 1310 0.25 2200 0.3 5980 2.11 5950 Cinders Cinders 2040 1.57 1650 1.14 1710 0.53 3630 1 are obtain weight loss in micrometers (µm), divide g(mz by 7.2. Source: Romanolf, M. Undergraound Corrosion. Government Printing Office, for National Bureau of Standards, Washington, DC, Circular 579, 227 pp. (407 refs.). 1957. ^.back to, top Home I About AGA I About Galvanizing I Galvanized Steel in Use I Technical Info I Members Only I Site_h Contact I Terms of Use r-----•---•-. —.. _.�_.._. .._. .._.------- — ------- AGA-Protecting Steel fcr ,.?erreratinrrs] http://www.gaivanizeit.org/showContent,305,349.cfm 10/24/2006 Page 1 of 2 Ed Wimmer From: Roger Williams [Roger@torrentresources.coml Sent: Friday, October 13, 2006 3:26 PM To: Ed Wmmer Subject: Gestation Periods Ed, the best way I found to support the length of time it takes for the reproductive cycle was to gather selective information from the internet. Some state websites indicate that reproduction can occur in as little as 48 hours, and some in 72 hours — see below. According to the National Institute of Allergy and Infectious Diseases, scientists have identified at least 40 of the approximately 200 species of mosquitoes that live in the U.S. and Canada which can transmit the West Nile Virus. Mosquito Life Cycle Like butterflies, mosquitoes undergo complete metamorphosis and have egg, larval, pupal, and adult stages. Each of these four stages is easily recognizable by its unique appearance. Eggs: Mosquito eggs are laid individually or together to form "rafts" which float on top of the water. Culex and Culiseta species mosquitoes lay their eggs stuck together in rafts of up to 200 eggs. Anopheles, Ochlerotatus and Aedes species do not make egg rafts, they lay their eggs singly. Culex , Culiseta and Anopheles species lay their eggs on the water's surface. Mosquito Egg Raft Hatching Aedes and Ochlerotatus species lay their eggs on damp soil that will eventually be flooded by water. Most eggs hatch within 48 hours depending on temperature. Water is a necessary element for mosquito reproduction. Like the majority of insects, mosquitoes have four (4) distinct life stages: egg, larva, pupa, and adult. Some mosquitoes lay their eggs on the water surface, either glued together in group called rafts (Anopheles, Coquillettidia, and Ochlerotatus) or as multiple, single egg deposits (Culex and Culiseta). The eggs usually hatch within 48 hours. Others mosquitoes, so-called "floodwater" species (Aedes and Ochlerotatus), lay eggs in damp soil where the eggs can survive up to several years until flooded by rain or irrigation water, or by rising streams and marsh boundaries. From Maricopa County Vector Control in Arizona: • Typical Breeding Sites Irrigation or rainwater that ponds and stands for more than three days, such as over -irrigated or poorly leveled yards and pastures, tail -water ponds, desert ponds, stock tanks, backed up washes and flood control drainage areas. . Eggs: Exposure to high humidi at the water line for 2-3 days is_ required for larvae to 10/27/2006 Page 2 of 2 hatch from their eggs. However, if the eggs dry out before this development period, they will collapse and the embryos will die. If they remain unhatched above the water line, and the level of humidity is sufficient to permit larval -embryo development, eggs become "cured." This means they are resistant to desiccation and can survive for upwards of six or more months. They can also survive short periods of subfreezing weather. Later, when exposed to water, the eggs will hatch within a day or perhaps even within minutes. The eggs do not all hatch with a single inundation, however. Instead, they hatch in progressively smaller numbers through a succession of inundations. 10/27/2006 , United States Office of Water EPA S32-F-01-005 Environmental Protection Washington, D.C. September 2001 Agency IEPA Storm Water Technology Fact Sheet On -Site Underground Retention/Detention DESCRIPTION One of the major components of stone water management is flow control, particularly in newly - developed areas where buildings, parking lots, roads, and other impervious surfaces replace open space. As imperviousness increases, there is less area available for infiltration, and the amount of runoff increases. This may cause streams to be more prone to flash floods. Many municipalities now require newly -developed areas to maintain pre - development runoff conditions and to implement measures to capture or control the increase in peak runoff for a design storm event. Several different types of storm water Best Management Practices (BMPs), including retention/detention ponds, storm water wetlands, and underground storage structures, can provide storm water volume control. These BMPs capture flow and retain it until it infiltrates into the soil (storm water retention) or release it slowly over time, thereby decreasing peak flows and associated flooding problems (storm water detention). Several of these options, including storm water wetlands and large detention ponds, require relatively large land areas, making them less of an option in areas where land costs are high or where land availability is a problem. In many of these areas, such as parking lots for malls or other developed sites in highly urbanized areas, storing storm water underground on the site may be the best option. Underground storm water retention/detention systems capture and store runoff in large pipes or other subsurface structures (see Figure 1). Storm water enters the system through a riser pipe connected to a catch basin or curb inlet and flows into a series of chambers or compartments for storage. Captured runoff is retained throughout the storm event, and can be released directly back into surface waters through an outlet pipe. Outlet pipes are sized to release stored runoff at pre - development flow rates. This ensures that there is no net increase in peak runoff and that receiving waters are not adversely impacted by high flows from the site. Some systems are also designed to exfiltrate stored runoff into the surrounding soil, where it helps to recharge the groundwater table. Underground retention/detention systems can be constructed from concrete, steel, or plastic materials. Each material has advantages and disadvantages and specific applioabilities, which are discussed in the following sections. APPLICABILITY Underground retention/detention systems are primarily used in newly -developed areas where land cost and/or availability are major concerns. They are not usually designed for retrofit applications. Most systems are built under parking lots or other paved surfaces in commercial, industrial, and residential areas. Perforated underground retention systems that release stored storm water into the subsoil are recommended only for areas with well -drained soils and where the water table is low enough to permit recharge. Some pretreatment such as sediment traps or sand filters may be necessary for infiltration to eliminate sediment and other solids that could clog the system. On -site underground retention/detention systems provide peak runoff flow control and can store storm water for future release back into the environment. However, they are not designed FIGURE 1 SCHEMATIC OF PIPE -BASED UNDERGROUND STORM WATER DETENTION SYSTEM specifically to enhance water quality; therefore, other storm water BMPs may be required to provide storm water treatment. Underground retention/ detention systems are often used in "treatment trains," which consist of a number of storm water BMPs that provide both storm water treatment and storage. For example, storm water entering the underground detention structure in Hauge Homestead Park in Everett, Washington, is first collected from a parking area through a catch basin, then flows through a series of vegetated swales, then into a storm water pipe with a sump, all of which filter out sediment and pollutants before the runoff reaches the detention chambers. Runoff is then released into a pond at a controlled rate, where fiuther pollutant removal occurs (City of Everett, Washington, Department of Parks and Recreation, 2000). ADVANTAGES AND DISADVANTAGES This Section presents the overall advantages and disadvantages of on -site underground retention/detention systems. The advantages and disadvantages of specific designs and construction materials (concrete, steel, plastic) for underground retention/detention systems are discussed in the Design section. Advantages • The primary advantage of the on -site. underground storm water retention/ detention system is that it captures and stores runoff, thus helping meet the requirement to maintain pre -development runoff conditions at newly -developed sites. • These systems are ideal for highly urbanized areas, particularly in areas where land is expensive or may not be available for ponds or wetlands. • These systems can be installed quickly. For example, construction and installation of a 6' by 4' by 156' concrete system was installed under a car dealership in Tennessee in 3 days (Sherman Dixie Concrete Industries, Inc., 2000). • These systems are very durable. Once in the ground, most systems can last more than 50 years. • Because these systems are underground, local residents are less likely to have access to them, making them safer than ponds or other aboveground storm water BMPs. Disadvantages • The primary disadvantage of the on -site underground storm water detention structures is that they are not designed to provide storm water quality benefits. However, if they are included in a treatment -train type system, underground detention systems can be an important part of an overall storm water management process. • These systems may require more excavation than surface ponds or wetlands. • Recharge of the groundwater from an underground retention unit may contribute to groundwater contamination if flow from the site is directly discharged into the retention system before pretreatment. Therefore, EPA does not recommend that percolation systems be designed for sites with coarse soils or high groundwater tables. • These systems are more difficult to maintain and clean than aboveground systems. DESIGN CRITERIA On -site underground retention/detention systems are designed to provide a predetermined amount of storage volume within a specified area. System designs can range from simple storage pipes or chambers to complex systems consisting of multiple pipes or chambers, with accompanying joints, crossovers, multiple inlets and access points. At a minimum, each system must have an inlet, an outlet, and a structure to , access the chamber (Pacific Corrugated Pipe, 2000). All other design elements are site, project, and material -specific, as described below. Among the most important elements to consider when designing underground retention/detention systems are the size, shape, and physical characteristics of available space available for the system. These factors will influence how the system is constructed and what type of construction material is chosen. Depending on the specific application, design engineers have utilized different materials, including concrete pipes and other concrete structures, steel pipes, and plastic pipes, in designing underground retention/detention structures. Each material has different advantages and disadvantages under different scenarios. The type of material to be used in any individual application should be determined by site and application -specific conditions. Site -specific considerations that may influence the type of material used in an individual application include: • The depth and area of allowable excavation space. For example, to maintain the structural integrity of corrugated steel and high density polyethylene pipe systems, more fill is required below, between, and above the pipes than when using concrete. • The shape of the area available for the system. For example, is the available space one continuous area where a large vault could be placed, or does it have angles which might make a pipe system more appropriate? • The depth of the water table. For example, there are some concerns that plastic pipes may float upward in areas with high water tables. • The construction costs (including material and labor costs) for different materials. Table I summarizes the physical characteristics of these materials. Additional considerations include local ordinances, which may preclude the use of some types of materials for certain applications. For example, Fairfax County, Virginia, does not TABLE 1 COMPARISON OF DESIGN CONSIDERATIONS FOR CONSTRUCTION MATERIALS FOR UNDERGROUND STORM WATER RETENTION/DETENTION SYSTEMS Construction Material Shapes Spatial Requirements Rigidity/Flexibility Fill Requirements Other Requirements Available Sizes Concrete Plastic Steel and Aluminum (HDPE) (CMP) Rectangular vaults or Circular pipes, semi-dreular circular pipes Circular pipes pipe -arches, or other special shapes Primarily continuous space Can be fitted into irregular Can be fitted into irregular with no angles and angled spaces and angled spaces Very rigid, does not require fill to maintain rigidity; not flexible Requires minimum fill above structure Rigid, requires fill for stability; not flexible Requires minimum fill between and above pipes Requires minimum spacing None between pipes. Water table must be below level of pipe Multiple sizes that can be Multiple pipe diameters are pre -cast or kaavailable; all are pre - pre -cast manufactured Rigid, requires fill for stability; can withstand some shifting without breaking or buckling Requires minimum fill between and above pipes Requires minimum spacing between pipes 12" to 144" diameters and pipe arches are available pre -assembled. Larger diameter pipe and pipe - arches are available for assembly orrsito Handling Requires moving equipment Can be moved by hand Requires moving equipment Source: Compiled by Parsons Engineering Science, Inc., 2000. allow plastic pipes to be used for underground retention/detention systems for residential areas. In contrast, plastic pipe has been the favored option for systems built by the Department of Parks and Recreation in Everett, Washington. Once appropriate construction materials are determined for a specific application, design must determine the amount of storage volume required by the system. As discussed above, many areas have adopted a policy of no net increase in runoff for a design storm event for newly -developed areas. Thus, the required storage volume is the difference between pre and post -development runoff: In other areas, local requirements dictate how much of a given storm must be captured and treated, and the required storage volume can be calculated using this value. For example, the City of Malibu, California requires post -construction treatment control BMPs to treat the first 0.75 inches of rainfall over a 24-hour period (City of Malibu, 2000b). In contrast, the Department of Public Works in Everett, Washington, requires systems to be designed for the 6-month, 24-hour storm (City of Everett, Washington, Department of Public Works, 2000). After the required storage volume has been determined, the design engineer can examine the site to determine what configuration will maximize storage while minimizing the size of the excavated area. Concrete structures, such as box culverts, tend to provide greater storage volume per excavated area because of their rectangular shape (allowing more storage volume per cross -sectional area) and the fact that they can provide one continuous chamber. Pipe systems, on the other hand, tend to store less runoff per excavated area. There are several reasons for this. First, round pipes and pipe arches have less storage volume per cross -sectional area than do square structures, such as box culverts. In addition, pipes are often laid parallel or at intersecting angles, reducing the amount of storage per excavated area. Pipes also require specific amounts of space for fill between them. While this promotes the structural integrity of the pipes, it reduces the amount of excavated area available for storage. These requirements make the largest diameter pipe that meets the minimum cover requirements the most economical. For example, doubling the diameter of the pipe usually doubles the cost of the pipe, but quadruples the storage volume. In addition, the ability to angle and arrange pipes in series of different lengths may make them good choices when the space available for storage is not continuous. Several manufacturers have produced CD-ROMs to aid in the design and configuration of pipe systems. R 1 PTO "My" On -site runoff controls, such as underground storm water retention/detention systems, are designed to control storm water quantity and they have little impact on storm water quality. Thus, underground storm water retention/detention systems alone will not satisfy most local storm water regulations. For example, Fairfax County, Virginia, requires both storm water management (i.e., storm water volume control) and storm water BMPs (i.e., storm water quality control) (Fairfax County, Virginia, 2000). Therefore, most underground retention/detention systems are coupled with other water quality BMPs, such as catch basins, curb inlets, water quality inlets, sand filters, or sumps. This "treatment train" can help to improve the water quality of the overall storm water control system, particularly during the first part of a rain event when pollutants may be at their highest concentrations. BMPs maybe located either upstream or downstream from the retention/detention system. Fairfax County, which reviews storm water plans for new development, encourages planners to include sand filters or other water quality control devices upstream of an underground detention system. The City ofMalibu, California, recommends a treatment train system (City of Malibu, California, 2000b). One system that the city has looked at includes a sedimentation basin, a detention basin, then a sand filter (City of Malibu, California, 2000a). A new project in Hauge Homestead Park in Everett, Washington, includes storm water BMPs both upstream and downstream of the detention area. When designing a treatment train, design engineers must ensure that downstream BMPs are designed for the appropriate flow from the: underground retention/detention system. For example, the City of Alexandria, Virginia, found that long drawdown times from underground retention/detention systems could result in continuous flowinto downstream sand filters, which could cause the resuspension of accumulated phosphorous (City of Alexandria, VA, 2000). Therefore, Alexandria does not recommend the use of sand filters downstream from most retention/detention systems. While underground storm water retention/detention systems are not specifically designed to provide water quality benefits, they do often improve water quality. As storm water is retained before it is released back into the environment, suspended solids may settle out, thereby reducing the overall pollutant load. For example, in the City of Everett, Washington, local regulations require that at least 15 percent of the 6-month, 24-hour storm runoff be retained above ground, usually in a biofrltration area. The remainder of the runoff can be stored below ground, where suspended solids are allowed to settle out before the water is released back into the environment (City of Everett, Washington, Department of Public Works, 2000). However, unless the system is properly maintained, settled solids may eventually fill the system. OPERATION AND MAINTENANCE Once underground storm water retention/detention systems are installed, they require very little maintenance. They have no moving parts and remain intact for many years. A major concern with the use of corrugated steel or polyethylene pipes has been that the pipes might crack or buckle over time because of the weight of the soil surrounding them. However, a study of corrugated steel pipe (CSP) underground storm water detention structures in the Washington, D.C., metropolitan area conducted by the National Corrugated Steel Pipe Association (NCSPA)(NCSPA, 1999) found that all of the systems were performing well. None of the pipe systems inspected, some of which had been in place for up to 25 years, showed signs of buckling, cracking, or bending. In only one case had the joints of pipe sections separated. Underground storm water retention/detention structures must be cleaned periodically to remove accumulatedtrash, grit, sediments, and other debris. The installation of catch basins or grates at the inlet will reduce trash accumulation, but suspended solids will still be carried into the storage area, where they may settle out and accumulate on the bottom of the structure. The structures need to be cleaned to remove this accumulated material, which should be tested to determine if it contains any toxic or hazardous materials, and then disposed according to local regulations regarding storm water residuals. In Fairfax County, Virginia, where there are over 300 underground storm water retention/detention structures installed at commercial/industrial sites, private owners of the structures are required to sign a maintenance contract with the County that commits the owner to maintain the structure appropriately. Fairfax County also provides owners with a maintenance checklist and plans to inspect these structures regularly (i.e., at least once every five years) to ensure that they are functioning adequately. If an owner fails to maintain the structures, the maintenance agreement allows the County to perform the required maintenance at the expense of the owner. The City of Everett, Washington, takes ownership of underground storm water detention systems constructed in residential developments under existing rights -of -way, such as sidewalks or streets. The city conducts annual inspections of system outlet structures and looks for an accumulation of sediment at the outlet as an indicator that the system needs to be cleaned. Crews are then dispatched to perform the clean -outs. The City also regularly inspects private systems and issue notices to owners when sediment accumulation is noted (City of Everett, Washington, Department of Public Works, 2000). COSTS Costs for underground storm water retention/detention structures are highly variable and depend primarily on the types of materials used (concrete vaults, metal or plastic pipes) and the amount of storage volume desired. The type of materials used will greatly affect construction and installation costs, because they dictate the size of the excavation required to achieve the necessary storage volume. As discussed in the :Design section, to ensure their strength and rigidity, plastic and steel pipes have specific requirements for spacing, fill type and fill volume, all ofwhich effect the size of the excavation. Concrete structures do not have the same level of fill requirements. Another consideration is the amount of time required to handle and assemble the various pieces of the system. Steel and plastic pipes tend to be lighter and easier to handle than concrete vaults; however, large diameter pipes and "pipe arch" structures (which are delivered as separate sheets and must be bolted in place) may increase handling time requirements. While costs for specific types of underground detention systems can be highly variable, they can be very economical, especially compared with alternatives. The primary alternative to an underground storm water detention structures is an aboveground wet detention pond. While construction costs for ponds are generally lower than for underground storage units (ponds can cost between $17.50 and $35 per cubic meter of storage area [Center for Watershed Protection,1998]), land used for a surface pond cannot be used for any other purpose. This is not true for underground retention/detention systems, where the land above can be utilized for parking lots or other purposes, maximizing the economic potential of the Land. In Everett, Washington, underground detention structures are often used in conjunction with aboveground ponds in storm water management. While local regulations require some surface treatment of storm water, the majority of runoff can be stored underground, minimizing the need for large surface ponds that are both costly and require economically -valuable land. Everett also encourages the use of concrete underground storage systems, which allows the pond to actually be placed directly on top of the underground storage area, again making maximum use of the available land (City of Everett, Washington, Department of Public Works, 2000). Underground retention/detention systems can also be economical I when compared to infiltration trenches. An engineering estimate prepared for a commercial installation in Glen Burnie, Maryland, showed that a 150,000 cubic feet detention system consisting of 60" corrugated steel pipe covered by stone would cost approximately $453,000 and occupy only 0.94 acres, while a stone infiltration trench that could store the same volume would occupy 1.43 acres and cost $576,000 (Contech, Inc., 2000). The major differences in cost between these two options were that using only stone required a larger excavation, and the stone fill and increased labor for placing the stone fill was more costly than the cost of material and labor for installing the pipe. As discussed above, underground storm water retention/detention structures can vary greatly in cost, depending on the materials utilized, the excavation, construction, and installation costs, and the storage volume required. For example, construction of the underground storm water retention/detention segment ofthe Boneyard Creek project in Champaign, Illinois, which consisted of the installation of six 11-foot diameter corrugated steel pipes (comprising 24,600 cubic meters of storage) cost approximately $9 million, plus contingencies (City of Champaign, Illinois, 2000). When combined with a larger, aboveground storm water retention/detention pond, this project provides enough retention/detention for a 25-year storm event, preventing the perennial flooding of Champaign's Campustown section and saving local businesses from flood damage and lost business. Engineer's estimates for installation of CSP systems in Arizonaare approximately $84 percubic meter of storage (Pacific Corrugated Pipe Co., 2000). For example, to capture the first inch of runoff from a one acre plot, 72 feet of 96-inch CSP would be installed at a cost of $8,650. Costs are scalable and increase proportionally to increases in the amount of land served or the amount of runoff stored. High Density Polyethylene (HDPE) pipe was utilized to construct an underground storm water detention system at the T.F. Green Airport in Providence, Rhode Island. The parking lot was created when an existing neighborhood was demolished to create extra parking areas. The site had a high water table and no runoff 'was allowed to leave the site. The contractor designed five separate systems of 24-inch HDPE pipe, with the largest systems consisting of approximately 2,500 linear feet of pipe each, to contain the runoff. The total storage volume was 1,426 cubic meters. While the contractor determined that 36-inch pipe was the most cost effective option, this would have had required regrading before installation while maintaining three feet of soil between the pipe and the groundwater as required by Rhode Island regulations. The total project cost was $250,000, which included 9,200 linear feet of 24-inch HDPE pipe, inspection ports, filter fabric, filter sand bedding, nine inches of stone fill around each pipe, and almost three feet of fill over the pipes (D'Ambra Construction Co., Inc., 2000, and Vanasse Hangen Brusilin, Inc., 2000). There are trade-offs in costs between pipes and other systems, such as concrete vaults. In some cases, costs for concrete storage structures can be lower than those for plastic or corrugated steel pipes. Because they require less area to achieve the same storage volume, less area may need to be excavated for concrete structures than for pipe systems. This may reduce excavation costs: Using complete precast concrete sections can decrease assembly time, further reducing costs. However, these low costs may be offset by the higher costs of handling concrete. Installation of a 156-foot long section of 6-foot by 4-foot concrete precast box culvert (106 cubic meters) at a au dealership in Knoxville, Tennessee, was completed in 3 days and cost approximately $85,000 (Sherman Dixie Concrete Industries, Inc., 2000). Case Study: Hauge Homestead Park, Everett. Washin on The City of Everett, Washington, undertook a project to detain increased runoff generated from new facilities (including a dock, a pier, restrooms, and walkways) in Hauge Homestead Park on Silver Lake. Only 4 acres of land was available for the park, some of which was required for a wet detention pond to capture nmoff generated from the facilities. However, because space was so limited, the Parks and Recreation Department wanted to minimize the size of the pond while still providing the required treatment. The solution was to build an underground storm water retention/detention system upstream of the pond to store excess runoff until it was released at a controlled rate into the pond. Because the flow into the pond was controlled, engineers could design a smaller Pend that still achieved the same pollutant removal efficiency. The underground retention/detention system was composed of 350 feet of 36-inch HDPE pipe, which provided 2,847 cubic feet (80.6 cubic meters) of storage. When added to the 804 cubic feet of shallow pond and 1,869 cubic feet of deep pond, the storage capacity exceeded the 5,130 cubic feet required to handle a 25-year storm event. The total cost for the underground detention system, including materials and installation, was $28,190 (City of Everett, Washington, Department of Parks and Recreation, 2000). Case Study: Homestead Village Hotel, Brookfield, Wisconsin In order to meet the requirements for no net increases in runoff volume from the construction of the Homestead Village Hotel in Brookfield, Wisconsin, engineers designed an underground retention/detention system consisting of 549 feet of 72-inch concrete pipe. Many new development projects in the suburban Milwaukee area utilize retention/detention ponds to control runoff because land is usually available; however, in this case, the hotel was built into the side of a hill, and construction of a pond required re -grading the site and increased costs. Thus, the system was built in a ring around the hotel, with all roof and floor drains connected to the system. The designers chose concrete pipe for several reasons: • The large size requirement (72 inch pipe); • The owners wanted a 100-year plus product lifespan; • Multiple openings were required in the pipe for the drain inlets and the designers felt that concrete pipe would maintain its strength under these conditions; • This pipe required a relatively small amount of fill. • Both HDPE pipe and CSP were eliminated as alternatives based on concerns that the soil conditions would corrode CSP pipe and seals required for HDPE pipe did not meet the State pressure -testing requirements. The system storage capacity is 120,000 gallons, with outlets through 7-inch diffuser perforations and also through a 12-inch outlet pipe, which eventually flows into a roadside ditch, then into a nearby stream. Overall project costs were approximately $267,000, including sanitary and storm sewers (APS Concrete Products, Inc., 2000, and National Survey & Engineering, Inc., 2000). Material costs for the concrete pipe accounted for approximately $75,000 of this total. Case Study: Jordan Landing, West Jordan, Utah Jordan Landing is a retail mall in West Jordan, Utah, covering 80 acres and consisting of retail stores and parking lots. The complex had no requirement to detain runoff onsite. One option for runoff generated by the site was to divert the runoff to storm water structures downstream. However, these structures were not large enough to handle the increased flows, and the cost of constructing the piping to convey the runoff downstream and enlarging the downstream controls was deemed too high. Therefore, the owners opted to detain the runoff onsite. Because space was at a premium on the site, the designers chose on underground retention/detention as the best option to control runoff. They considered several options for the detention system, including corrugated steel pipe, aluminum pipe, HDPE pipe, concrete vaults, and reinforced concrete boxes, before deciding that 48-inch aluminum pipe was the best option. The other options all had major drawbacks: CSP required an expensive coating to protect it from site soil conditions, significantly increasing costs; costs for HDPE pipe were high because the system design required numerous expensive "T" fittings; the only reinforced concrete boxes immediately available came in specific pre -manufactured sizes that did not fit the site (in some places on the site there was only six feet of allowable excavation); and concrete vaults were too large and expensive. The selected system utilized helical aluminum pipes fastened with aluminum bands. The system was installed by first laying down the header pipes, which were designed so that the barrel pipes could be laid directly into them, saving costly fittings. The barrels were then fitted into the header, and bands were used to connect the pipes together. Six separate galleries of aluminum pipe were initially constructed. A seventh was added later. Altogether, the project utilized 20,000 feet of pipe and achieved 7,120 cubic meters in storage volume. The overall construction costs for the project were $1.2 million (Nolte Associates, 2000). Water Quality Inlets EPA 832-F-99-029 September 1999 Wet Detention Ponds EPA 832-F-99-048 September 1999 Other EPA Fact Sheets can be found at the following web address: http://www.gpa.gov/owmitnet/mtb act.htm 1. Advanced Drainage Systems, Inc., 1997. Technical Note 2.120 Re: Storm Water Detention/Retention System Design. A summary of comparative costing information for on -site underground storm water retention/detention 2• systems is provided in Table 2. Other Related Fact Sheets Handling and Disposal of Residuals EPA 832-F-99-015 September, 1999 Advanced Drainage System, Inc., 2000. Materials provided to Parsons Engineering Science, Inc., by Steven Marsh, Advanced Drainage Systems, Inc. 3. APS Concrete Products, Inc., 2000, Dennis Stevens, APS Concrete Products, Inc., personal communication with Parsons Engineering Science, Inc. 4. Center for Watershed Protection, 1998. Costs and Benefits for Storm Water BMPs. TABLE 2 COMPARATIVE COST INFORMATION FOR ON -SITE UNDERGROUND STORM WATER RETENTION/DETENTION PROJECTS Boneyard Jordan T.F. Green Hauge Homestead Car Creek, Landing Airport, Homestead Village Dealership, Champaign, Mall, West Providence, State Park, Hotel, Knoxville, IL Jordan, UT RI Everett, WA Brookfield, TN WI Material CSP Aluminum HDPE HDPE Concrete Concrete Box Culvert Length of Pipe 8,600 20,000 12,500 350 549 156 (feet) Diameter of 132 48 24 36 72 6 x 4' box Pipe (inches) Maximum 24,600 7,120 1,420 81 454 106 Instantaneous Storage Volume (cubic meters) Overall Cost $9,000,000 $1,200,000 $250,000 $28,190 $267,000 _ $85,000 Source: Compiled by Parsons Engineering Science, Inc., 2000 5. City of Alexandria, VA, 2000. Bill Hicks, Department of Public Works, personal communication with Parsons Engineering Science, Inc. 15. 6. City of Champaign, IL, 2000. Jeff Smith, Department of Public Works, personal communication with Parsons Engineering 16. Science, Inc. 7. Contech Construction Products, Inc., 2000. Patrick Pusey and Dutch Van Schoonveld, Contech Construction Products, Inc., 17. personal communication with Parsons Engineering Science, Inc. 8. D'Ambra Construction Co., Inc., 2000. 18. John Oliver, D'Ambra Construction Co., Inc., personal communication with Parsons Engineering Science, Inc. Standards to Reduce Water Pollution, March 3, 2000. National Corrugated Steel Pipe Association, 1999. "Condition Survey of Corrugated Steel Pipe Detention Systems." National Survey & Engineering, Inc., 2000. Fred Spelshaus, National Survey & Engineering, Inc., personal communication with Parsons Engineering Science, Inc. Nolte Associates, 2000. Paul Hacunda, Nolte Associates, personal communication with Parsons Engineering Science, Inc. Pacific Corrugated Pipe Company, 2000. Darwin Dizon, Pacific_ Corrugated Pipe Company, personal communication with Parsons Engineering Science, Inc. 9. Dewberry & Davis, Inc., 2000. George 19. Sherman Dixie Concrete Industries, Inc., Kovats, Dewberry & Davis, Inc., personal 2000. Al Hogan, Sherman Dixie Concrete communication with Parsons Engineering Industries, Inc., personal communication Science, Inc. with Parsons Engineering Science, Inc. 10. Everett, Washington, Department of Parks 20. Thompson Culvert Company, 2000. Chris and Recreation, 2000. Ryan Sass, City of Hill, Thompson Culvert Company, personal Everett, Washington, Department of Parks communication with Parsons Engineering and Recreation, personal communication Science, Inc. with Parsons Engineering Science, Inc. 11. Everett, Washington, Department of Public Works, 2000. Jane Zimmerman, City of Everett, Washington, Department of Public Works, personal communication with Parsons Engineering Science, Inc. 12. Fairfax County, Virginia, 2000. Steve Aitcheson, Fairfax County Municipal Water Management, personal communication with Parsons Engineering Science, Inc. 13. Malibu, California, 2000a. Rick Morgan, City of Malibu Department of Public Works, personal communication with Parsons Engineering Science, Inc. 14. Malibu, California, 2000b. Rick Morgan, City of Malibu Department of Public Works, memorandum to applicants for new development regarding New Development 21. Vanasse Hangen Brustlin, Inc.,, 2000. Molly Rogers, Vanasse Hangen Brustlin, Inc., personal communication with Parsons Engineering Science, Inc. ADDITIONAL INFORMATION American Concrete Pipe Association Josh Beakley 222 West Las Colinas Boulevard, Suite 641 Irving, TX 75309 City of Champaign, Illinois Jeff Smith Department of Public Works 702 Edgebrook Drive Champaign, IL 61820 _ . 1 Contech Construction Products, Inc. Phil Perry P.O. Box 800 Middletown, OH 45044 Dewberry 8& Davis, Inc. George Kovats 8401 Arlington Blvd. Fairfax, VA 22301 Nolte Associates Paul Hacunda 710 Rimpau Ave. Corona, CA 92879-5725 Pacific Corrugated Pipe Company Darwin Dizon P.O. Box 2450 Newport Beach, CA 92658 Vanasse Hangen Brustlin, Inc. Molly Rogers 530 Broadway Providence, RI 02909 Virginia Department of Conservation and Recreation Larry Gavan 203 Governor Street, Suite 213 Richmond, VA 23219-2094 The mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Environmental Protection Agency. For more information contact: Municipal Technology Branch US EPA 1200 Pennsylvania Ave;, NW Mail Code 4204M Washington, DC 20460 oMTB r.&� MVNICIYAL TECHNOLOGY BRAN H ,�% Earth Systems Southwest October 29, 2006 City of La Quinta P. O Box 1504 La Quinta, California 92247-1504 ArrAC,Hkl-�tJT � 79-911B Country Club Drive Bermuda Dunes, CA 92203 (760)345-1588 (800) 924-70 15 FAX (760) 345-7315 Attention: Mr. Tom Hartung Director of Building and Safety Subject: Cathodic Protection of Underground Retention Chamber System Project: PM 30903; Washington Park La Quinta, California Dear Mr. Hartung File No.: 10854-01 06-10-808 As you requested, Earth Systems Southwest [ESSW] offers this letter of our opinions and conclusions regarding corrosion of the proposed metal underground retention chamber system for the proposed development, currently under considered by the City of La Quinta. As part of our review, we have used various reference materials consisting of technical information provided by: Caltrans, L. A. County, Army Corps of Engineers, Department of Transportation/Federal Highway Administration [FHWA], the American Galvanizers Association, and other geotechnical engineering reports that represent soils in the vicinity of the subject site. Additionally, we understand that the site development included importing soil from locations not made known to ESSW. It should be noted that the vast majority of projects that are included in the general documentation from the sited government agencies are centered primarily on public projects. Although this does not, in any way have an impact on the performance of galvanized metals, it is important from a maintenance and potential replacement standpoint. Although this point may sound trivial, it has profound implications on enforcement, insurance of scheduled inspection and maintenance, and the burden of repair or replacement. The failure of such systems generally results in unnecessary lawsuits. Additionally, ESSW has not reviewed site -specific design concepts, locations, or details for the proposed pipe. Therefore, some of our conclusions focus on potential problematic elements of the system. We understand that the proposed retention system will be constructed of 5 gauge galvanized metal plate arches with a maximum center height of about 13 feet. We further understand that during the 100-year design, the design engineer calculates that water levels of up to 12 feet may occur. ESSW recognizes that this is the "worst design case." We also recognize that given the low annual rainfall in the Coachella Valley, a greater impact in the desert is collected nuisance water. The system is open on the bottom and is designed to retain water and disposal of the collected water by infiltration through the bottom. ESSW is not aware of any proposed filtration to separate oils or suspended solids from the collected water prior to discharge into the basin. However, the system is a retention system and will not be subject to the mechanical mechanism of corrosion by abrasion. October 29, 2006 - 2 - File No.: 10854-01 06-10-808 Clearly, concrete and galvanized metals are used throughout the United States, largely with success for a given design life. However, there are also cases where corrugated metals fell short of the design service life due to corrosion issues. The most significant factors regarding soils used for backfill on the outside of the arch include aeration (grain size of soil and permissible evaporation), moisture content, pH, temperature, and resistivity. As stated in the FHWA document the "Soilside corrosion is complex but usually is not a significant factor in pipe life exce t in very arid, sandy regions where rainfall is minimal." This condition exists in the Coachella Valley. Consequently, most of the article is devoted to the water -side of the galvanized metal. As stated above, borrow material (import soil) is reported to have been brought to the subject site at various times in the past. Therefore, the degree of potential corrosion is partially dependent upon the actual soil that comes in contact with metal arch. Site soil, tested by Anaheim Test Laboratory, indicates pH of 7.2 and 7.5; soluble chlorides of 148 ppm and 630 ppm; and resistivity of 730 ohm -cm and 1,533 ohm -cm. ESSW's experience of soils in the vicinity of the site suggests a fairly wide range of test results. This suggests a conservative approach to be used in the design. We understand that the design includes a gravel layer, located on the outside of the metal arch. This will aid in providing improved aeration and separation of the soil from the metal surface. ESSW is not aware of the basin location or its proximity to landscaped areas or other sources of moisture. Additionally, ESSW has not reviewed structural details that would indicate how nuisance water is mitigated on the outside of the arch. Many of the potential corrosive chemicals are water soluble. Therefore, should water become trapped in the top of the supporting foundation, then the metal arch would be exposed for an unknown length of time. This base on the metal at the point of connection to the foundation is also a location that is exposed to higher structural loads. The interior of the basin is subject to water of unknown chemistry. This includes water collected during periods of annual rainfall as well as nuisance water. In addition to the collected silts and road oils, much of the nuisance water will consist of runoff from irrigation. The irrigation could be potable water provided by the Coachella Valley Water District's network of pipes or reclaimed water as a part of the ongoing need to conserve water. In any event, the chemistry of the collected water will have an impact on the rate of corrosion and the design. As mentioned earlier, maintenance on private projects is difficult and burdensome for regulatory agencies to govern. Consequently, this is an area generally over looked until an issue presents itself, by which time damage has usually occurred. Long-term performance of the retention basin is affected by constituents that may "seal off' the bottom of the basin allowing nuisance water to collect and breach to the top of the foundation exposing the metal arch to water from inside the sy stem. Therefore, based on the information made available to ESSW and our experience in the north La Quinta area, we suggest that the acceptance of a proposed buried metal arch chamber system, as described above, have the following items considered as part of that decision. ➢ The infiltration rate and the subsequent design of the proposed metal arch chamber system should be based on geotechnical data obtained from the results of double ring infiltration testing performed at the proposed bottom elevation and performed in accordance with ASTM testing procedures. The geotechnical investigation should thoroughly explore the soil to AARTH SYSTEMS SOUTHWEST a October 29, 2006 - 3 - File No.: 10854-01 06-10-808 verify uniformity of soils to a depth of at least 10 feet below the proposed bottom. The consultant should identify zones that may restrict the anticipated flow and layers that may be impervious, where impervious is considered to be an infiltration rate below the allowable threshold of the governing agency. ➢ The proposed system should be strategically located such that there is at least 30 horizontal feet from the outermost edge of the system to any area that is irrigated. ➢ Irrigation in areas within 50 feet of the system should consist of drip irrigation to reduce the potential of overspray and the eventual migration of surface water over the proposed system. Collected runoff should be conveyed to the subsurface chamber system through a network of underground pipes as opposed to surface flow to a common inlet. ➢ Hardscaping over the top of the chamber system should be kept in good repair to limit infiltration of moisture that may have an adverse effect on the outside of the metal chambers. ➢ We understand the metal arches will be protected from direct contact with the native soils by the use of a gravel layer. A geotextile fabric consisting of a 4 oz non -woven material should be used as a separator to be positioned between the gravel layer and the native soils. ➢ The top of the footing (inside and outside) should be sloped down and away from the point of connection between the metal arch and concrete footing to prevent long term collection and exposure of the metal to the collected water. ➢ The water entering the system should be pre-treated to remove oils, sand, silt, or other materials that may be detrimental to the long term performance of the system. The bottom 3 feet of the metal arches should be protected with a polymer coating. The coating should be in accordance with AASHTO M245, M246; ASTM A 742; ASTM A762. A routine maintenance program should be established to remove accumulated debris or other undesirable material from the infiltration surface. ➢ The maintenance program should contain, at a minimum, routine inspection of the interior of the metal arches. If the surface is determined to exhibit adverse or accelerated corrosion, immediate treatment will be required. Should you have any questions concerning our report please give us a call and we will be pleased to assist you. Sincerely, EARTH ', Vh �. )�* M CE 38234 EXP. 137/07 Craig S. Hill CE 38234 Distribution: 4/City of La Quinta 1/RC File 2/BD File EARTH SYSTEMS SOUTHWEST poll A A On G) r+ ® ♦ / e' < w CD CD- Cc- o — o 3 �CD � r4L�_ CD W , ® �• CCDD ® 0 CL C � < o CD � ..+1 U) (n CDCD— Q: C CL 9: `< o _ CD o _. c � o U• o 0 CD � CD CQ 0 � cn O� � ®. - �. p ® O to CD n- � �. 0 r v o C: 0 cn ® ch (DD CD .� C 0 0 3t e I �ylt i3 � t � 4 r E C (D I< R W \VT N N .r-Er rF CD CD 9 0 N 0 0 V ! ..... q a) 'z1 0 �V r r 0 } o Vl^' A IAR 9 r.• • Lj WNW" w "No~ ' No oil logo MI' �t t m� Mi 1= wirrl . tuwrr 0 n X n D r n O X O ch O z r O 0 D O z G) m 0 O X O O z 00 v m cn z 0 X 0 D r 0 O X O z r O 0 D z cn 0 O X X O z 12 z;r 1:7 Sl Lmwnmj 1?4 Un ig eD Ev. rx�Ei. 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"O Q � v X C =r CD _ C: to Omn O O< CD CD n (- on �, 0 CD N �_ o _0�Or+00-0 O CD 0 CD C: CD Cn CD 'I o Cn(n 0- O CD v < in — -v CD �' o CD 0 Fn' v o O su CD 0 No 0 0 m v Cn CD M CD CD CD v c CD cn CD M. 0 cn CD CD r CD 0 03 O on CD 0 CA CQ' O CD Structural Design Check for Structural Plate Pipe per AASHTO Standard Specifications for Highway Bridges, Section 12 Pipe Description Shape: Arch Corrugation: 6" x 2" Diameter (S): 300 in Gage: 0.218 in Area (A): 3.199 sq in/ft Moment of Inertia (1): 0.1270 inA4/in Radius of Gyration (r): 0.690 in Modulus of Elasticity (E): 2.90E+07 lb/sq in Yield Strength (Fy): 33,000.0 lb/sq In Tensile Strength (Fu): 45,000.0 lb/sq in Seam Strength (SS): 112,000 Ib/ft Safety Factors Loads Wall Area: Buckling: Seam Strength: Dead Load Unit Weight of Soil: Height of Cover: Pdl = Pdl = 2.0 2.0 3.0 120 Ib/cu ft 4 ft 12b lb/cu ft x 480.0 Ib/sq ft Live Load Live load pressures are shown on an attached sheet. Total Load Pt = Pdl + PII PII = 298 lb/sq ft botts/ft = 4 4 ft Pt = 480.0 lb/sq ft + 298.0 lb/sq ft Pt = 778.0 lb/sq ft Actual Wall Stress Thrust (T) = Pt x (Spanf2) T = 778.0 lb/sq ft x 12.50 ft T = 9,725.0 lb/ft Wall Stress (fa) = T / A fa = 9,725.0 lb/ft / 3.199 sq in/ft fa = 3,040.0 lb/sq in Find Maximum Allowable Wall Stress Wall Area Fa=Fy/SF Fa = 33,000.0 Ib/sq in / 2.0 Fa = 16,500.0 Ib/sq in 16,500.0 Ib/sq in > 3,040.0 Ib/sq in Actual SF = 10.86 Buckling r/k x (24 x E / Fu)A.5 = 390.1 in > 300.0 in Therefore, Fa = [Fu - ((FuA2 / 48 / E) x (k x S / r)A2)] / 2 Fa = 15,845.0 Ib/sq in 15,845.0 Ib/sq in > 3,040.0 Ib/sq in Actual SF = 10.42 Handling and Installation Strength Flexibility Factor (FF) = SA2 / (E x 1) FF = 0.024 Allowable FF = 0.030 0.030 >= 0.024 Seam Strength Required Seam Strength = T x FS SS required = 9,725 Ib/ft x 3.0 SS required = 29,175 Ib/ft 112,000 > 29,175 Ac£uae Sr = 11.52 OK OK OK Vehicle Live Load Vehicle Type = H2O or HS20 Type of Axle = Tandem Height of Cover (h) = 4.0 ft. Axle Load = 25,000 Ibs Tire pressure = 100 psi Wheel load (P) = 12,500 Tire contact area = 125 sq in Tire contact length (L) = 0.69 ft. Tire contact width (w) = 1.47 ft. Tire spacing, center to center, (s) = 6.0 ft. Axle spacing, center to center, (a) = 4.0 ft. Tandem Axle Live Load Pressure, p = 4 ' P / (((1.75 • h) + w + s) * ((1.75 ' h) + L + a)) for eg"am CONSTNUCnON MNODUClS INC. w C-nfech-cpi.<om = 298 Darwin Dizon, P.E. Regional Sales Engineer 751 Weir Canyon Road #157621 Anaheim Hills, CA 92808 Office: 714-281-7883 Fax: 714.281-78,34 Cell: 909-659-5463 Dizon D@contech<pi. co m 298 CONSTRUCTION�1►a �PROODUCTS INC. Mark A. Taylor Sales Manager Phone: 909/895-8900 184S onrechticpCOM ssCe Fax: 909/859-7585 1845 So. Business�C 92408 r., Suite 118 Email. muYlor@contech-cpl.com San Bernardino, COMBO WALL INSPECTION LIST FIRST INSPECTION NAL INSPECTION IS FOOTING SECOND INSPECTION IS BOND BEAM )URTH INSPECTION FOR RET WALL THIRD INSPECTION GROUT INSPECTION TO VERTFY SOLID GROUT IN RET WALL AND STEEL PROPERLY I INSPECTION INSTALLED FOR WALL ON TOP IINSPECTION FOURTH INSPEMON BOND BEAM FOR TOP WALL VERTICAWHORIZONAL FIFTH INSPECTION IS A FINAL INSPECTION **RLL STEE�TO BE Ist INSPECTION !N PLRCE PRIOR TO RNY INSPECTION P.O. Box 1504 78-495 CALLE TAMPICO LA QUINTA, CALIFORNIA 92253 October 19, 2006 Mr. Jack Tarr Washington 111, LTD 80618 Declaration Avenue Indio, CA 92675 BUILDING & SAFETY DEPARTMENT (760) 777-7012 FAX (760) 777-7011 RE: Appeal of the Decision of the City Manager concerning La Quinta Staff discretionary policies regarding the suitability of alternate materials and methods of installation for an underground retention facility as applied to the Washington Park development. Dear Mr. Tarr: A hearing before the Board of Appeals for the above matter has been set for October 31, 2006 at 2 PM in the City Hall Session Room. Please provide to the Building and Safety Department five (5) copies of any materials that you would like the Board to review prior to the hearing. I will need said materials no later than October 26, 2006, in order for them to be included in the packets provided to the Board Members. If you have any questions please feel free to contact me at 777-7019. Sincerely, Tom Hartung Director of Building and Safety M. Katherine Jenson, City Attorney P.O. Box 1504 LA QUIN'IA, CALIFORNIA 92247-1504 78-495 CALLL TAMPICO (760) 7 7 7 - 7 0 0 0 LA QUINTA, CALIFORNIA 92253 FAX (760) 777-7101 October 10, 2006 Mr. Jack Tarr Washington 1 1 1, LTD. 80618 Declaration Avenue Indio, CA 92675 Re: Appeal of the decision of the City Manager concerning La Quinta Staff discretionary policies regarding the suitability of alternate materials and methods of installation for underground retention facility as applied to the Washington park development. Dear Mr. Tarr: Thank you for your letter dated October 6, 2006. Please be advised the appeal has been forwarded to the Building and Safety Director for review. Any questions related to the appeal board should be directed to the building official. Once the initial review is completed by Building and Safety, you will be notified of the date of the hearing. If you have any questions regarding this matter, please feel free to contact Tom Hartung at (760) 777-7013. 1SSiin-cerely, tl Don Adolph Mayor TRJ/cd c: Thomas Genovese, City Manager Tom Hartung, Building and Safety Manager Tim Jonasson, Public Works Director T:\STAFF\Jonasson\Letters 2006\061010 Jack Tarr Appeal Reply.doc C C, Tom WASHINGTON III, LTD 80618 DECLARATION AVE. INDIO, CA 92201 October 6, 2006 City of La Quinta 78-495 Calle Tampico La Quinta, CA 92253 Honorable City Council: 760-775-7967 Phone 760-775-8329 Fax On September 8, 2006, Washington 111, Ltd. submitted an Appeal of the Decision of the Director of Public Works (on Behalf of the Building and Safety Department) and Appeal of the Decision of the City Manager Concerning La Quinta Staff Discretionary Policies Regarding Suitability of Alternate Materials and Methods of Installation for Underground Retention Facility as applied to the Washington Park Development. To date we have not been notified that the appeals board has been chosen, nor received any information setting forth the qualifications and experience of the members with the proposed application solution. We are respectfully requesting the Council take action to assure that the appeals board be chosen and an appeals board hearing date be set forth in a timely manner, I Partner gton 111, Ltd. � o O y r n 03 �y _rn 7 CO 'n n rn C-rl C P.O. Box 1504 LA QUINTA, CALIFORNIA 92247-1504 78-495 CALLE TANIPICO (760) 7 7 7 - 7 0 0 0 LA QUrNTA, CALIFORNIA 92253 FAX (760) 777-7101 October 2, 2006 Mr. Jack Tarr Washington 111, LTD. 806 18 Declaration Avenue Indio, CA 92675 Re: Appeal of Decision of Director of Public Works (On Behalf of the Building and Safety Department) and Appeal of the Decision of the City Manager Concerning La Quinta Staff Discretionary Policies Regarding Suitability of Alternate Materials and Methods of Installation for Underground Retention Facility as applied to the Washington Park Development Dear Mr. Tarr: Thank you for your letter dated September 8, 2006. City staff received a large amount of information about underground drainage facilities from your consultant engineer, Steve Speer, at a meeting held on September 22, 2006. A proposed design was submitted today by Mr. Speer which has been forwarded to the Building Department for review, at the conclusion of which a hearing will be scheduled for your appeal. If you have any questions regarding this matter, please feel free to contact me at (760) 770-7042 or Ed Wimmer, Principal Engineer, at (760) 777-7088. Sincerely, (Imothy . Jon on Public Works Director/City Engineer TRJ/EJW/cd c: Tom Genovese, City Manager Tom Hartung, Director of Building and Safety Deborah Powell, Acting City Clerk File C:\Documents and Settings\cdiaz\Local Settings\Temporary Internet Files\OLK86\060928 Jack Tarr Underground Retention Appeal 1-irst Reply5.doc MEMORANDUM OF rk�k TO: John Thompson, Young Engineering Services FROM: Greg Butler, Building & Safety Manager DATE: October 5, 2006 RE: Conceptual Review —Underground Retention Chamber Enclosed, please find some documentation related to the proposed Underground Storm Water Retention Chamber mentioned in my recent a -mail. This matter centers on differing opinions between the design engineer and the City Engineer regarding the concept of utilizing a plate steel rather than concrete structure for this purpose. The letters from Speer Civil, dated June 5, 2006 and October 2, 2006 will likely give you the quickest overview before reviewing the rest of the material. The developer has already requested a hearing in front of our Appeals Board. Consequently, t request that you put this ahead of anything else that you're doing for us. An unfavorable ruling there could send it to City Council, so our goal is to obtain from you an official opinion on: 1. The general suitability of using a steel structure (instead of the more commonly seen concrete) for this purpose; 2. If suitable, with what limitations, particularly in locations with corrosive soil; 3. Its suitability for use beneath a building or parking lot; 4. If suitable, an appropriate design life, and; 5. Other factors (e.g., maintenance, etc), as you deem relevant. EM 4 SPEER Civil CONSULTING ENGINEERS keC mj you cmk de commwdy awl yar envision June 5, 2006 Timothy R. Jonasson, Public Work Director/City Engineer LA QUINTA PUBLIC WORKS DEPARTMENT 78-495 Calle Tampico La Quinta, CA 92253 Dear Mr. Jonasson: Underground Storm Water Retention Chamber— Galvanized Metal Plate Arch Washington Park, PM 30903 Pursuant to our phone conversation late last week regarding the subject underground storm water retention chamber, and its forecasted service life, please find enclosed herewith the supporting infomnation that I stated would bring some science to this topic. The enclosed info is divided into two sections that I have entitled: 1) the Parson Brinkerhoff Study, and 2) Galvanized Metal Durability Info: 1) The "Parsons Brinkerhoff Study' file contains the results and information gleaned from a comprehensive study conducted by Parsons Brinkerhoff of galvanized corrugated metal storm water detention systems in the Washington DC area. Their study concludes: a. `the total service life of the structures would be in excess of 100 years' (pgs 6 & 8) b. The thickest, pipe metal, included in the study was 10 gauge (pg 5). Most were in the 12 to 16 gauge range, where the bigger the gauge number the thinner the metal. (Note: the metal plate structure proposed for Washington Park will be 5 gauge). c. PB found the AISI Method (based on the Caltrans Method) provides a more aocurate/realistic service life prediction than the California Method (pgs 6 & 8). W855 WASWNGTON ST • SWTE C-280 ♦ LA QUINTA ♦ CN FORMA 92253 Office: 760.285.7335 Fax: 760.269.3580 ww Spee ml.net Timothy R. Jonasson June 5, 2006 Page 2 of 3 d. The service life of detention systems appears to be driven by soil -side corrosion (pg 8). PB made that statement because they found no significant water -side invert deterioration. It should be noted that the structure proposed for Washington Park will have an open bottom (ie no metallic invert) thus the findings of the PB study are extremely relevant to the Washington Park proposal. 2) The `Galvanized Metal Durability Info' is a compendium of three documents consisting of. 1) a service life calculation by Darwin Dizon with Contech, 2) selected pages from the Handbook of Steel Drainage & Highway Construction Products publish by American Iron and Steel Institute (AISI), and 3) the soils report for Washington Park. Relevant info in this file includes: a. Mr. Dizon estimates the service life of the proposed structure for Washington Park to be 289 years using the AISI Method (see calculation on pg 2). b. The AISI formula is typically used for estimating the service life of the structure invert where abrasive flows are a factor, but the Washington Park application has no invert. As a result, the formula `may be overly conservative for structural plate' applications (such as Washington Park) as stated on pg 7. PB's Washington DC study, which validated the AISI formula for estimating service life of detention systems where soil -side corrosion is the key factor, provides reassuring relevance to Mr. Dizon's use of the formula. c. By design, the zinc coating on the metal plate acts as a sacrificial anode in the corrosion process in lieu of corrosion attacking the structural steel. Hence, the service life of the structure is a function of how long the zinc coating provides cathodic protection. The primary factors in the soil contributing to rapid deterioration of the zinc coating are: low pH, low electrical resistivity, and high moisture content. The soil at Washington Park offers a favorable set of conditions for implementation of a galvanized metal plate structure, to wit: 1. "The predictive method.... depended on whether the pH exceeded 7.3.` (pgs 6 & 7) The soil pH at Washington Park is 7.5 (pg 12) 2. The electrical resistivity for Washington Park is 1533 ohms and in mid -range to the soils encountered in the PB study. 3. The moisture content in the Washington Park soil is low in most locations, but does increased to as much as 29% in the deeper clay layers. 50855 WASWNGTON ST • SurrE C-280 • "OUWA • cAIIFORMA 92253 Office: 760.285.7335 Fu: 760.269.3580 wmspe rcivitmi Timothy R. Jonasson June 5, 2006 Page 3 of 3 In conclusion, the anticipated service life of the proposed galvanized 5 gauge metal Plate structure for Washington Park far exceeds the 100 year threshold. The projected 289 year service life is hard to fathom yet the formula has been validated by two studies, a California study which is briefly cited in the A1SI Handbook (pg 6) and extensively discussed in the Parson Brinkerhoff study. The primary factor contributing to the lengthy service life is the thickness of the metal plate and its associated thicker zinc coating. The apparentteason for galvanized corrugated metal pipe having such a checker history regarding its service life is two -fold: 1. The pipes were typically small diameter (relative to the 25-foot diameter proposed for Washington Park) and as a result, the metal thickness was quite thin (16 to 12 guage) which came with a commensurately thin zinc coating. 2. The pipe invert was the primary location of failure due to abrasive flow and constant exposure to water. The Washington Park structure will have an earthen invert, thus the most critical location for failure is non-existent in this application. Let me know if you need any additional information regarding the Washington Park proposal. I can be reached at 760.285.7335 Sincerely, Steve Speer, Principal SPEER Civil 50855 WASl9NOTON ST ♦ SUITE C•280 ♦ LA OtANTA ♦ CAIFOMIA 92253 Oflim 760.285.7335 Fax: 760.269.3560 w .speerdvil.rret SPEER Civil CONSULTING ENGINEERS ... Re(peng +you create tPe commla t� asset you en won October 2, 2006 Timothy R. Jonasson, Public Work Director/City Engineer LA QUINTA PUBLIC WORKS DEPARTMENT 78-495 Calle Tampico La Quinta, CA 92253 Dear Mr. Jonasson: Underground Storm Water Retention Chamber — Galvanized Metal Plate Arch Washington Park, PM 30903 My guess is — it's equally puzzling for you, as it is for me, regarding how our view points of galvanized metal products have parted to polar opposites. First let me say I do not believe I have sold -out simply because I'm paid to represent my client. To the contrary, our view points may not have been fully aligned as I neared retirement last fall. Not because I disagreed with your perspective then, but most likely because the differences, if there were any, were unspoken or unknown to each other regarding the respective view points that we each consider to be the critical aspects of designing an underground retention facility. For me, the critical aspect of designing an underground retention basin is duplicating the basic elements of surface retention basin design in an underground facility. Doing so means developing a facility geometry that includes an open bottom design and relatively easy access to the chamber for cleaning and inspection. The type of material used to accomplish that end was not critically important in my opinion, primarily because I believe the choice of materials is a function of strength and durability, which in most cases can be resolved with proper application of the material. One of the key reasons I choose to forego the Cabazon visit last year was the fact I considered that facility to be the wrong application for La Quinta and a waste of time to consider it (call me close minded here). The Cabazon facility is a `detention" facility not a "retention" facility. As a retention facility it does not possess what I consider to be the critical design aspect — it does not possess an open bottom. As a result, the percolation surface is inaccessible for cleaning and will silt up rendering the facility useless long before the structural service life of the facility is met. 50855 WASHINGTON ST ♦ SUITE C-280 ♦ LA OUINTA ♦ CAUFORNA 92253 Office: 760.285.7335 Fax: 760.269.3580 w .speercivil.net Timothy Jonasson October 2, 006 Page 2 of 5 However, based on your comments, and comments of engineering staff, your joint assessment of the Cabazon facility as a poor example for duplication in La Quinta is more material based than geometry based, which explains the basis for my earlier statement that our view points were not fully aligned last fall. I did not know that you considered the Cabazon facility to be a bad example for retention basin design because of its material. The Washington Park Proposal The good news is my client concurs with the open bottom, easy access, design concept for underground retention facilities. However, the challenging aspect of his proposed facility is the choice of material. He has chosen galvanized metal. In our ongoing discussions since early June, I believe his proposal has been judged by a biased jury. I don't mean that in a critical way. We all have biases, because all of us have experienced different things in life, and in our professional careers, and those experiences provide the basis for our decision making. Given that candid premise, biased juries can make sound decisions --- when they understand where the bias is entering the decision making process. If I had known that you considered galvanized metal a non -starter because of your experience at Cabazon and Ed's experience in Newport Beach I would have provided a more distinct and clearer difference in the documentation I originally supplied, between those examples which are the reference basis for your decision making, and the product that is proposed for Washington Park. Unraveling the Bias The most fundamental aspect in using galvanized metal and obtaining a longer service life is found in the thickness of the metal used in the facility. A thicker metal with a thicker coating of galvanizing material (zinc) equates to a longer service life. There are other factors that also impact service life, and I'll address that a bit later, but the key aspect to unraveling the bias is found in the metal thickness. I suspect your experience with galvanized metal has been with relatively small diarneter corrugated metal pipe (ie 48" diameter or smaller). Small diameter pipe is typically fabricated of 16 gauge metal because a thicker gauge is not needed to fulfill the structural needs for the intended application. However, 16 gauge metal has a .much thinner galvanized coating and therefore does not provide the long service life that reinforced concrete pipe provides, thus it is easy to see how and why one would start to insist concrete is a better material than galvanized metal. But that comparison, and its antidotal conclusion, does not give galvanized metal a fair hearing. Just as there is a design science associated with using concrete, there is a design science associated with using galvanized metal. If achieving a long service life is a critical design aspect for a given facility, and galvanized metal is the material of choice, it can be achieved by properly applying that design science. If a designer does 50855. WASHINGTON ST ♦ SURE C-280 ♦ LA OUINTA ♦ CALIFORNIA 92253 Office: 760.285.7335 Fax: 760.269,3580 w .Speewlvil.net Timothy Jonasson October 2, 006 Page 3 of 5 not apply the design sciences of the respective materials in the design process, facility failure is a realistic possibility. In fact, there's a strong argument that designing facilities with these materials without applying the related design sciences could be considered non-professional practice. Mainstream Engineering Practice What I did not know in June (nor most likely did your staff) but I now understand as a result of hours of research regarding this material is: A very good, if not the best, source for design guidance regarding the use of galvanized metal products is Chapter 850 in Caltrans' Highway Design Manual. 2. The leading, public sector, authorities in the public works field: the Federal Highway Administration (FHWA), the US Army Corps, and Caltrans all consider galvanized metal to be a useful material in building publicly financed facilities. Using galvanized metal products is clearly in the mainstream of engineering practice. Galvanized metal is not an inferior product unless it is applied in a non-professional way Ignoring the science that supports its use. Similar Facilities Galvanized metal products are widely used for underground "detention" basins throughout the country. But there isn't a lot of existing "retention" basins to cite as examples because storm water retention is not a widely employed practice outside the Coachella Valley and the Phoenix area. Nevertheless, certain aspects of the two types of facilities can be compared. They both fill up with storm water during the storm event, then percolate or release the water over a period of time. As a result, it's reasonable to compare the "water" side of the facility for service life longevity. That information was submitted in the original submittal made in June. The use of detention basins elsewhere in the United States is a result of NPDES regulations. Detention basins are a standard BMP facility for use in improving storm water quality. Starting at the EPA website and perusing online documents one can find references to the source of information they promulgate. An early document that is widely cited by governing authorities across the nation is a document entitled "Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban BMPs" published in 1987 by the Metropolitan Washington Council of Governments, Washington, DC. I have not seen the document because it's not available online. But it clearly has impacted the design practice across the nation from the DC area to the Pacific Northwest to California. In all locations, galvanized metal is used for underground detention basins. The Parsons Brinkerhoff study that was submitted to the La Quinta Engineering Department in June contained a critical review of several galvanized metal facilities constructed in the DC area. It should be noted that none of the facilities reviewed by Parsons Brinkerhoff were constructed of 5 gauge metal. They 50855 WASHINGTON ST ♦ SUITE C-280 • LA QUINTA ♦ CALIFORNIA 92253 Office: 760.285.7335 Fax: 760.269.3580 w v.SpemiviLnet Timothy Jonasson October 2, 006 Page 4of5 were all constructed of much thinner metal. Hence the Washington Park facility will yield a very substantial service life because it is constructed of thicker metal. The FHWA websitetti has an online manual entitled "Stormwater Best Management Practices in an Ultra -Urban Setting". The text associated with Figure 11 in that manual says: 'Detention tanks and vaults are underground structures used to attenuate peak stormwater flows. They are usually constructed out of either concrete or corrugated metal pipe (CMP) and must consider the potential loading from vehicles on the vault or pipe..... Some design information on CMP systems is available in Design and Construction of Urban Stormwater Management Systems (ASCE, 1992)' Clearly, galvanized metal is a commonly facilities and there are recognized sources consult in preparing their facility design, Design Process used material for underground detention of information for design professionals to It's recommended that the Caltrans design process be adopted for designing galvanized metal facilities in La Quinta. Caltrans is one of the leading research agencies regarding the use of galvanized metal. When FHWA wanted to produce a document regarding the use of galvanized metal they turned to the US Army Corps which in turn relied on Caltrans documentation in their preparation of the FHWA document. That twin showing of confidence in Caltrans' information on this topic by the leading authorities in public works design in the United States is hard to ignore. Additionally, the Highway Design manual cited earlier in this letter was published just last month (Sept 1, 2006), therefore, it quite likely contains the latest and most authoritative guidance available in using galvanized metal. The Proposed Facilitv The underground retention facility proposed for Washington Park will employ an open bottom design utilizing 5 gauge galvanized metal plate arches that are twenty five feet (25) wide at the bottom with a rise of twelve feet six inches (12' 6") from the bottom of the arch to the high point, and set on linear concrete footings. The facility will be constructed under the parking lot near its lowest elevation. We are seeking concept approval at this time, Design details will be addressed in the plan review process. (1) http://www.fhwa,dot.gov/environment/ultraurbfindex,htm 50855 WASHINGTON ST ♦ SUITE C-280♦ LA QUINTA ♦ CALIFORNIA 92253 Office: 760.285.7335 Fax: 760.269.3580 w .speerdviLnet Timothy Jonasson October 2, 006 Page 5 of 5 The attached picture, which has been provided in prior submittals, provides a good visual concept of what is proposed, except, the Washington Park facility will not have four "tunnels" like the facility in the picture, it will have just one. Additionally, the Washington Park facility will not have its access opening built into the concrete bulk head, but instead it will occur in the top of the arch near the bulkhead and use the bulkhead for placement of ladder steps. The attached cross-section shows the proposed trapezoidal bottom that will be used subject to verification by a soils engineer the underground embankment can handle the soil pressure imposed by the concrete footing without any subsidence. Conclusion This submittal, along with the two previous submittals regarding this proposal provides significant information regarding the quality and concept of the proposed facility. Nonetheless, if additional information is needed please advise. Sinc rely, Steven Q. S er Principal Attachments 50855 WASHINGTON $T ♦ SUITE C-280 ♦ LA QUINTA ♦ CALIFORNIA 92253 OMM: 760,285.7335 Fax: 760,269.3580 w .speercivil.net 0 o o 0 c E W O m a 0 aa- a0 N >E c S °'� Sd m aNi o� EU y' cm my �c ca 3 c ccaa a a o c =E o cc T y N O v O C = N U _o th .- ry O 0 N Oy N w N m N CD 0 c C O E a j aE 0. 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F j ARIZONA ]DEPARTMENT OF ENVIRONMENTAL QUALITY October 2002 ! f Y That Use #w Control and or TypesPretreatment Technologies Under the Aquifer Protection Program General Permit 0 and drywell guidance manual contains; O a summary of aquifer protection rules and other regulations that drywelis may be subject to; O clarifications of certain parts of both drywell general permit rules; O an evaluation of certain stormwater pollution control devices O general guidelines for design, installation, maintenance and inspection of all drywells. ' I I/ t"'wV,a -"�ddj r a 0 V / 6" \0 rO t lkXZkri4 £ o 0 0 > . g { ) ƒ- [ _ ) , 02 ] CD G=®m k-00 # 0 ® ;oiG ^ \\pa ^ Kw \ k z \\\ }\ \\ /\ 72 ,\° T \o \° M) 13 o I (2 /\ /} } ® Qo a ]! m§ 0 )§ Jam ,z0 . . . \ \i {0 (D m , ) >, M q e = �\ ow G = \\.[)ƒ7( § . . » 3 /({`& // `~\ s ,- Is. F m > $ � \ m H j 0 \� 0 §q §§_ 2� @\ to 5 § .\ @ .0 m 0 / \ N 0 I P.O. tioa 1504 LA QUrNTA, CALIFORNIA 92247-1504 78-495 CALLE 'FAMPICO (760) 777-7000 LA QUtNrA, CALIFORNIA 92253 FAX (760) 777-7101 August 25, 2006 Mr. Jack Tarr Washington 111, LTD. 30240 Rancho Viejo Road, Suite B San Juan Capistrano, CA 92675 Re: Underground Retention for Washington Park Dear Mr. Tarr: The meeting that you requested about underground retention was held at the City on Thursday, August 3, 2006. It was acknowledged by everyone at the meeting that the intended application for the underground storage was beneath a parking lot for a commercial development. It was also acknowledged that failure of the structure could result in the collapse of the parking lot. This structural collapse could affect adjacent buildings, cause economic loss to both tenants and the City, and/or cause citizen injury, In this event, the entire retention facility and parking lot would have to be reconstructed. It was also acknowledged by everyone at the meeting that a concrete underground structure would have a longer service life than a metal underground structure under identical conditions. It is a common practice in engineering to evaluate alternative materials, especially if there are cost differences. A cost analysis provided by your consultant, Steve Speer, shows that a concrete structure would cost about $462, 000 while the equivalent metal structure would cost only $257,650. The difference in cost is $204,350. Given this particular application (underground retention below a parking lot), and the potential adverse ramifications to the health, safety and welfare of citizens due to failure of the system, the Public Works department believes that it is in everyone's best interest to use the concrete system for this project. (Nothing that was presented at your meeting of August 3, leads me to believe that this conclusion is not correct. G:\Genovese, T\letters\Tarr, Jack re; Underground Retention 08-25-2006.doc M At the meeting, you asked for background information on how the City arrived at the 36 hour max retention time standard for underground retention as promulgated in the draft policy. Due to our limited experience with underground retention, my staff attempted to advance a reasonable standard that is accepted in other jurisdictions. The 36 hour max retention time standard is required by many local Arizona jurisdictions including Phoenix, Scottsdale, Tempe and Tucson. Additionally, the 36 hour max retention time standard is required by the Maricopa County Health Department (pest control requirement). Lastly, you expressed concern that Coachella Valley Water District staff may not be prepared to grant approval on deep dry wells. My staff has liaised with CVWD staff on this issue and is confident that CVWD will not delay approval of Maxwell or equivalent systems. These systems have already been approved by CVWD and have been physically installed on several projects in La Quinta. If you have any questions regarding this matter, please feel free to contact Tim Jonasson, Public Works Director/City Engineer, at (760) 770-7042 or Ed Wimmer, Principal Engineer, at (760) 777-7088. �Sincerely, / Thomas P. Genovese City Manager TRJ/EJW/cd c: Tim Jonasson, Public Works Dire for/City Engineer Ed Wimmer, Principal Engineer Paul Goble, Senior Engineer File GAGenovese, T\Ietters\Tarr, Jack. re Underground Retention 08-25-2006.doc m From: Tim Jonasson Sent: Tuesday, July 25, 2006 6:01 PM To: Ed Wimmer Subject: FW: Retention System Design Do we have anything on this? Tim Jonasson, PE Public works Director.JCity Engineer City of La Quinta (760) 777-7042 tjonasson@la-quinta.org -----Original message ----- From: Jack Tarr [mailto:tarr@cox.netj Sent: Tuesday, July 25, 2006 10:16 AM To: Tim Jonasson Subject: Retention System Design Tim: Steve Speer relayed on that the City has concluded that the concrete retention systems have a longer useful life than the steel system we provided as a potential substitute and for this reason the City has rejected our proposed solution. I would appreciate it if the City could provide me with any supporting documentation for this conclusion. our engineers have found no material that supports the City decision to reject our proposal based on useful life of our proposed system being inferior to the concrete system proposed by the City. Thank you. Jack Tarrco (949)240-2482 5 7v RM Act � ,ate. 5,- -� ( - --fie �Q Cep *-" r.- i ° LOW PROFILE : �, r , r ARCHON , . , [ i.. > 3 t y .. `� ( i i_l R i�t 1 UNDERGROUND STORMWATER MANAGEMENT y. ih..'N' 't SYSTEM F M CASE HISTORY LAUREL? MARYLAND INSTALLATION WafMart and Sam's Club Underground Stormwater Management for 60-acre site Installed Summer, 1995 ENGINEER Boyd and powgaillo Freeland and Clinkscales CONTRACTOR Atlantic Building Group and Roy Jorgensen Associates SIZES & QUANTITIES 33'-1"span x 12'-5" rise. .. 1, 100 1. 1, Low Profile Arches COMMENTS The SURER-SPANT" structures, used in leiu of a pond, provided 363,000 cubic feet of storage beneath 1.2 acres of the parking lot. The project also involved 5„000 feet of CONTECH ULTRA FLO' (15" through 48" diameters) and 5,000 feet of galvanized 8" corrugated metal pipe. 80 '.'ears of Innovation in Construction Products �i1€Q m q , CONSTRUCTION PRODUCTS INC, 996 COW ECH CONSTRUCT,ON PE:OC'JC.o INC MACti-190(21+„6).5MAP ULTRAaO.MJPEWSPAN aye Co, Nt ,n,a n+zrona tom... area C ECH CONST5XTION PRO<MIS MC, Mdf6nfix, OE, AWMIWEDSTEELSaartb-m alMSeS+.. --�.x#d;j•� ` of responding to last-minute ings along with pavement and c£'atigcs_ railroad Lots." The projected x t4 used to des.gn wing ' eompledan dais for the project- cross sections. o oce use the is 199F. ra� _ z•' ,i t progl am to create Contours for toectESa asnuricn maapxo i �' ~ f t , RM? proposed and -existing grads - depletion:. says True Gland. �. la, an en knneer with the Porf-af � LdltB"[Jliitl iq,L tfiW� . Los Angeles. "The software.;. '< helps its run any number of de- COSTS DOW : . Fo sign options very quickly. The ; _.__. _._..-..-_ software is van usettd because f mdjng a cost-effective win - if allon� us to visualize the Pon THE FaCtt.t U Azoo ACRE F Los AT iFiE PORT OF tLl$ At3UE1E5 'MILL to storm -water deters- area and see where problems ' tine was a key to successful situ. i :-��s` '�"`"""r� "�' ', BE THE LARGEST Of ITS KIND tN are happening, - prepamlion for the 60 acre Pitts- . N09TH AMERHA. y_ "Development of the eon- set Center, a shappmg complex 1 CONTRACTORS. �� SPAN ROERE AR NE WATER. tamer terming is currently tak- in Aisne Aruridel County Md i nEri NTON SYSTEM. ing place In rtuitinle. phases.' Tile consulting en�eenng` ---- ----- MOS says Gkiello. ifter initial •-firm Boyd and Dowgiailo neering grin Freeland and U1 COtxt7t Wt! rough grading construction Millersville, Md., designed the ; Ciiugscales- GeGeneralcentric- i the program willconsist o€sev complex, which had total water- I for for the water -detention prci - i he Port of Is,s Angeles has T :, era£ separate but integrated detention requirements of ; ect was. Atlantic Builders Group, ` begin construction of a 240 _ projects, many of which will be i about 36,309 on ft. Several ma- I Baltimore, assisted by eight acre container facility that will ' taking place at the same time," !- tesal alternatives were consid- ; subcontractors, be the largest of its tend in r As mitigation for dredging ered, including a 12o in. pipe £ After completion of the 30 ft `forth America The proJect's and landflInfir in the harbor, ; and aluminium arch. Engineers � deep excavation in November container yard was modeled us ' the part w21 enhance a 60 acre r decided the most cost-effective ' i993, construction of the foar'. lug Terraaxsdet, a land -model- ' wetlands area suffering from solution was the Super -Span i structures proceeded through'- ing program created by t Les 3 lack of tidal ficshhig. Shallow- low -profile anon from Con ech so;3xe of the worst winter weat}r Software of Atlanta. Ahuo�o all ; water habitat will be createdd ( Construction Product, Inc.. er in more than a decade.' -land modeling projects are now within the harbor to serve as 3 Middletown, Ohio. � Pumps were employed through - bring done either complatelp ° feeding area far the California t By choosing large s sue- ; out the winter to prevent site } or to pan with tmmpoters. least loco, an endangered bird tunes, the detention system re- 1 flooding and keep the i Port of Los Angeles engi- project on state and Raderal lists, The = quired only I acre of the 64 i on schedule. neer Robert Kaptein com ' TYrnamodei prog,ani was used acre plot. To make construction "Baciifill was the most diffi- ments. "Unlike line -oriented - to survey, design and build a and backfill easier, the faur ! cult part of the project, bwolv-; . systems. Torramode£ maps roar = new nesting site for these birds structures were spaced 10 ft ing four chambers 35 ft across, - nectlons between 3-D pomm, in the wetlands area, says + aparL 19 ft fail and 400 it long" says a ". . Because were dealing with dis- : Goiodlo- -. Engineers on the project ':. representative of Atlantic. '"the crete entities such as positions . When completed, the con- � were concerned about the prob- problem was the whole area: i and space to generate lines. talaer facility will cost$W4 rail- i ability of longterm water-deten- i had to be backfilled timnitana' this capability improves the ' lion and feature an on -dock i lion periods. Resulting backfill ; ously—and with the angular map's accuracy." infermodal rail yard. Constiur ! saturation -could mean backfill i stone rather than dill. We had - Kaptein adds that because lion began in early 1994. and i toss, so free -draining angular :? to provide concentric loading the program Wins eampletely En ; phase 1 of the project, which in- t stone with no fines was used. from start to finish." i r RANT, it is taster for contour gen- . `orations, eludes rough-gradingconstrue To protect the structures fur- p During the six-month project, l elevation extrspola. { tion of the container yard,.is ther, the entire ball enve- } Atlamids Crews poured more 4 Liens, cross sections, coordinate ; now being finished. lopewas wrapped with Trevire -{ than 1,2W tin yd of concrete, see geometry and other functions 'We've got the rough grade ; 1114 fabric to prevent in situ ; 2,204 ft of base channel and that run on top of computer -aid- ; and file major mfllides down;" fine-grain silts and clays from erected eight large concrete ed--design programs. Fn:add - f .says-Gioieille, "The wharf is go- imiltratiggthe stage. ' bulkheadwalls.The project Lilo i lion, the software's fast process- ing in. and now we're construct Drainage specifications were � completed on schedule. ,. ing speed aIsa eases ,he stress ; ing the infrastructure and build- developed with the site engi- taactt sot xur>4o«av+ce conconi ' 78 \ ) %)%g{(§ % § E EQ)SD=)§x. - -fit 444� \ -^e&m# \\f)/f- ,)Z)+\ § _ t�EEe= , �` {�k§\i Qw k{\k/\\\\}{\: �ta(DM (\§) ,- .__ �2Egle+»N»t, E MaGt==e«�»a=` - fE�&e«Za,al± � G -§®!=»��2+7±[ 3<&&;;oz56mmr « §(lzoE»»_ 4 „ I k\ /) 2(D 0- ( ' �� /) ) c I I I {\ \D -\ ! ( )> r /r _ \ / 2 [ } ) � co \ - [ _ 0 \ Page 1 of 4 Ed Wimmer From: Tim Jonasson Sent: Tuesday, June 27, 2006 4:59 PM To: 'Steve Speer' Cc: Bill Sanchez; Ed Wimmer, Paul Goble Subject: RE: Cost Effective Underground Storm Water Retention Facility Steve — When we first started this discussion while you were still with the city the concrete structure was estimated to be 4-5 times more expensive than the CMP alternative. It made sense to look at alternate materials with this amount of price difference. However, it looks like now the concrete alternative is less than twice as expensive. For the much longer service life I am having a hard time understanding why you would recommend the CMP option. Replacing CMP in culverts that are open on either end is a lot different than replacing an entire underground structure made of CMP. You basically would have to reconstruct the entire retention facility and parking lot. Without further information I believe it is in everyone's best interest to use the concrete structure system for this project. Tim Jonasson, PE Public Works Director/City Engineer City of La Quinta (760)777-7042 tj onasson(5a.la-quinta.org -----Original Message ----- From: Steve Speer [mailto:sspeer@speercivil.net] Sent: Monday, June 19, 2006 9:26 PM To: Tim Jonasson Cc: Bill Sanchez Subject: RE: Cost Effective Underground Storm Water Retention Facility UM We have competitive quotes from StormTrap (the product used at Sam's Club) and the Contech (the galvanized metal plate product). I apologize for the delay in responding, but I needed to clear it with Jack before releasing the cost info. The quotes are skewed a bit and need to be adjusted so we are comparing apples to apples with respect to facility size. Before we obtained a quote from Contech, we requested StormTrap to give us a quote for a 50,000 CF facility -- at the time it was looking like we may need one that big. However, since obtaining the StormTrap quote we have zeroed in on a 34,400 CF facility. StormTrap quoted us $462,000 including the installation cost. Contech quoted us $157,000 for a 34,400 CF facility for materials and erection. It is easier to adjust the Contech quote because it is linearly proportional. Thus, it can be increased by simply making it longer and adjusting the quote accordingly. A 45% increase makes it a 50,000 CF facility. A 45% increase in cost puts the material and erection cost at $227,650 plus other incidental costs such as the concrete end pieces and backfill which add another $30,000 pushing the galvanized metal plate facility to $257,650 installed. In summary: Concrete Facility Cost = $462,000 Galvanized Metal Plate Facility Cost = $257,650 Savings = $204,350 8/9/2006 Page 2 of 4 As I see it, the concept of using underground basins/chambers for storm water retention are in a phase of rapid design evolution -- in factjust about everything in engineering is evolving to some degree, but probably more so in underground retention at the current time as that engineering design concept gets more attention devoted to it. As a result, it seems more appropriate to spec an evolving facility design using a performance spec rather than a materials spec — doing so fosters creativity in design in the "early years" of innovation. An estimated 289 years of service life strikes me as a pretty significant performance time frame. Given that premise, 1 think the primary question is: Is the AISI Service Life formula a valid formula? The AISI formula is based on the inspections of over 7,000 Caltrans galvanized metal pipe facilities. The formula was critically reviewed by Parsons Brinkerhoff in their investigation of 17 galvanized storm water detention facilities in the Washington DC area. PB found the formula to be conservative in its estimate of service life for these types of facilities because deterioration in the invert is a non -issue as it is for most galvanized CMP facilities. Many State DOT's, if not all, continue to use galvanized CMP. They of course use it in smarter ways than that did in the past, but just because it may have a shorter service life than concrete they do not rule out its use. Likewise they do not rule out the use of asphalt concrete roadway pavement even though it has a shorter service life than Portland cement concrete. Planning for the rehabilitation and/or replacement of asphalt concrete pavement and galvanized CMP is an ongoing fact of life for all public agencies. All of the 7000 facilities reviewed by Caltrans, as well as the 17 facilities reviewed by Parsons Brinkerhoff, surely had some degree of degradation in progress probably quite similar in many ways to the facility you toured at Cabazon last fall. The degree of degradation was plotted and graphed, and resulted in the empirical AISI formula. I believe there is a preponderance of evidence supporting the continued use of galvanized metal for many types of facilities and is particularly well suited for using galvanized metal plate arches in the design of underground chambers because deterioration of the invert is a non -issue. Your timely decision regarding this matter is most appreciated Best regards, Steve Speer, Principal SPEER Civil Consulting Engineers 760.285.7335 Voice 760.269.3580 Fax www;speercivil n_et From: Tim Jonasson[mailto:tjonasson@la-quinta.org] Sent: Friday, June 16, 2006 10:50 AM 8/9/2006 Page 3 of 4 To: Steve Speer; Paul Goble Cc: Bill Sanchez; Ed Wimmer Subject: RE: Cost Effective Underground Storm Water Retention Facility Steve — Have you done a cost comparison between this structure and what they are currently building out at the Sam's Club site? The reason why I ask is that they are installing a modular concrete underground retaining system that might be comparable to this system in price. Tim Jonasson, PE Public Works Director/City Engineer City of La Quinta (760)777-7042 tjonasson(q',la-quinta.org -----Original Message ---- From: Steve Speer (mailto:sspeer@speercivil.net] Sent: Friday, May 26, 2006 12:38 PM To: Tim 7onasson; Paul Goble Cc: Bill Sanchez Subject: Cost Effective Underground Storm Water Retention Facility Tim & Paul, We have identified a cost effective way of handling underground storm water retention, and the system meets the primary requirements that we listed several months ago, to wit: 1) the underground chamber must be accessible for cleaning, and 2) must have an open bottom for adequate percolation. Additionally, it may be possible to eliminate the drywell. Having said that, here's why 1. Once the water is underground, there's no mosquito problem If there happens to be standing water in the chamber. 2. Purportedly, mosquitoes will not use a pool of standing water if it involves a flying a non -direct route into a darkened space to access the water (I am seeking confirmation of this through the American Mosquito Control Association which referred me to Dr. Marko Metzger with the California Department of Health Services, who apparently has extensive knowledge of retention basin dynamics with respect to mosquitoes) 3. The chamber will have a solid manhole lid, not a grated one. 4. The air vent will have a'sock' on it. 5. All passage ways into the chamber will be "mosquito -proof either by virtue of a solid lid, a mosquito mesh, or a pipe alignment utilizing a non -direct route. The attached photograph shows a mega structure compared to the one that is proposed for Washington Park. The underground structure at Washington Park (Phase 4) will be approximately 140 feet long, 25 feet wide, with 12.5 feet of internal head clearance. I'll call you after I've conferred with Or Metzger to discuss the design details of this structure Best regards, Steve Speer, Principal SPIER Civil Consul5ng Engineers 760.285.7335 Voice 760.269.3580 Fax www gperciv l.net 8/9/2006 Why Precast Concrete`? - Why Precast - NPCA Page 1 of 4 {- RESOURCE I +3 A41Gu4EFh ES 1 2RPCA "OP 14 GQ6 o SPECIFIERS Why Precast? Quality, Value, Permanence show the The average person likely is unaware of the presence of the hidden of pry; systems that make life what it is today: civilized. Sanitary and storm sewers, box culverts, catch basins, pump/lift stations, septic tanks, ° exterior grease interceptors, water storage tanks, wet wells, electrical and communication vaults and many other products all play a pivotal role in maintaining a clean, healthy, productive ;- w • environment for the inhabitants of the civilized world. Without these systems, life would be much different. Much of the ='- „s credit can be given to the main components of these systems, ° which typically consist of precast concrete. Here are some of the reasons why precast concrete is the ideal send P'Trast material for health, safety and protection of the environment: to the spw • a The many benefits of precast concrete include: reykNt °. ttemrctta etl: Strength Durability Mass Subscribe Buoyancy Fire resistance Chemical resistance Environmentally Search the Sae: Qualityconttol UV,sensitivity, .. __ ._.. friendly Reduced weather Weather resistance Watertightness Go! dependency Ease of installation Modulari Availability ®zoosrJvrg Efficiency Aesthetics low maintenance Strength. The strength of precast concrete gradually increases over time. ` Other materials can deteriorate, a experience creep and stress relaxation, lose strength and/or deflect over time. The load -carrying capacity of precastk3 concrete is derived from its own structural qualities and does not rely on the strength or quality of the surrounding backfill materials. Durability. Studies have shown that precast concrete products can provide a service life in excess of 100 years. For severe service conditions, additional design options are available which can extend the life of the precast concrete product. This is extremely important http://wtvw.precast.org/whyprecast/index.htm 8/2/2006 Why Precast Concrete'? - Why Precast - NPC;A Page 2 of 4 when calculating life -cycle costs for a project. [top] Mass. Precast concrete products can act as effective barriers to vehicular traffic due their size and weight. In the current world climate, precast concrete products such as planters, bollards and highway barriers increasingly are being used to provide protection for a wide variety of venues. Buoyancy. With a specific gravity of 2.40, precast concrete products resist the buoyant forces associated with below -grade construction. In comparison, fiberglass has a specific gravity of 1.86 and high -density polyethylene (HOPE) has a specific gravity of 0.97. [top] Fire Resistance. Precast concrete is noncombustible. Also, concrete does not lose its structural capacity nearly as quickly as steel, which is now a significant consideration as witnessed in the attacks on the World Trade Center and the towers' subsequent collapse. Other materials besides concrete and steel are flammable and/or do not perform well in elevated temperatures. Fiberglass begins losing structural integrity at 200 F. HDPE begins to melt at 266 F. Chemical Resistance. Precast concrete is resistant to most substances. However, no material is completely immune to attack from aggressive chemical agents. Thus it is wise to choose the material with the longest expected service life. Precast concrete products can be designed to withstand anticipated corrosive agents. [top] Quality Control Because precast concrete products typically are produced in a y controlled environment, they exhibit high ;.,.,...,,,,,,, quality and uniformity. Variables affecting quality typically found on a jobsite — temperature, humidity, material quality, craftsmanship — are nearly eliminated in a plant environment. UV Sensitivity. Unlike some other materials, precast concrete does not degrade from exposure to sunlight. This is extremely beneficial for above -ground applications. to j Environmentally Friendly. After water, concrete is the most frequently used material on earth. It is nontoxic, environmentally safe and composed of natural materials. Buried throughout the world, precast concrete products help convey water without contributing to poor water quality. Weather Resistance. Precast concrete is well -suited for exposure to http://www.precast.org/whyprecast/inde.x.htm 8/2/2006 wny Mcast concrete-! - Why Precast - NPUA Page 3 of 4 all types of weather conditions. In regions experiencing regular freeze -thaw cycles, the concrete mix can be designed to properly withstand damage. to ] Reduced Weather Dependency. Precast concrete increases efficiencyMbecause weather wilt not delayproduction. In addition, weather 'conditions at the jobsite do not "" significantly affect the schedule. This is because it requires less time to install precast compared with other construction methods, such as rast-in-place concrete. Precast concrete can be easily installed on demand and immediately backfilled —there is no need to wait for it to cure. Watertightness. Precast concrete, products produced in a quality - controlled environment and used with high -quality sealants offer a superior solution to watertightness requirements. Standard watertight sealants are specialty formulated to adhere to precast concrete, making watertight multiple -seam precast concrete structures possible. [top] Ease of Installation. Although precast concrete is quite heavy, nearly all other competing materials require machinery for handling and installation as well. Besides, speed of installation is more dependent on excavation than product handling and placement. Precast does not require the use of special rigging (such as fabric slings) which must be used in order to avoid structural damage while handling materials such as fiberglass. Additionally, because precast products are designed and manufactured for simple connection, many components can be installed in a short time. Modularity. Because of the modular nature of many precast concrete products, structures or systems of nearly any size can be accommodated. [top] Availability. With thousands of manufacturers throughout North America, precast concrete products can be ordered from plants in most cities or regions. Since precast structures are manufactured in advance and stored at the plant, they are readily available when needed at the job site. This ensures competitive pricing and a ready supply, which can save days, weeks or even months on a project over cast -in -place concrete. Efficiency. Precast concrete products arrive at the jobsite ready to install. There is no need to order raw materials such as reinforcing steel and concrete, and there is no need to expend time setting up forms, placing concrete or waiting for the concrete to cure. [topi http://www.precast.orghvhyprecast/index.htm 8/2/2006 wny Precast Concrete'! - Why Precast - NPCA Page 4 of 4 Aesthetics. Precast concrete products are both functional and decorative. They can be shaped and molded into an endless array of sizes and configurations. Precast concrete can also be produced in virtually any color and a wide variety of finishes (acid -etched, sandblasted, smooth -as -cast, exposed -aggregate) to achieve the desired appearance for building and site applications. Low Maintenance. Precast concrete requires little or no maintenance, which makes it an ideal choice for nearly any design solution. [top] http://www.precast,org/whyprecast/index.htm 8/2/2006 I 08/02/2006 WOD 15:35 FAX 9098298035 Pacific Corrugated Pipe {�001/002 ♦' ; . r ; ORDINANCE NO. 4(l AS AMENDED BY R E EFFECTIVE _9-16-as OB/02/2006 WED 15:38 FAX 9098298035 Pacific Corrugated Pipe 1&002/002 15. C U L V E R T P I P E 15.01 General: The type, strength, classification or gauge of drainage pipe to be furnished and installed will be designated on the plans. Details of the materials and work will conform with Standard Specifications and CalTrans Highway Design Manual Guidelines, published in January 1987. 15.02 Design Service Life: All drainage facility material types shall have a minimum design service life of 50 years. All metal pipes shall be subject to the requirements of the CalTrans Chart for 50 years Maintenance Free Service Life as contained in the CalTrans Design Manual. Soil tests using CalTrans Test Method 643 shall be provided to determine the pH and resistivity levels of the native soils and imported backfill materials. .5.03 Alternate Materials: When two or more materials meet the service life, the structura requirements, and the hydraulic requirements; the plans and specifications may provide for alternative pipe materials for optional selection by the contractor. Allowable pipe materials are: Aluminum Spiral Rib Cast -in -Place Concrete Corrugated Aluminum Corrugated Steel Reinforced Concrete Structural Aluminum Plate Structural Steel, Plate Steel Spiral Rib The use of aluminum pipe shall be limited to the acceptable levels for pH, resistivity, and flow velocities. The pH level of soil, backfill, and effluent shall range within 5.5 and 8.5, inclusive. The minimum resistivity of the soil, backfill, and effluent shall. be 1500 ohm -cm. Flow velocities shall not exceed 20 feet per second. When alterations or extensions of existing systems are required, the pipe material type may be selected to match the type used in the existing system. Each pipe material type selected as an alternative must have the appropriate protection from deterioration from corrosion, abrasion, or both. Corrosion may result from active elements in the soil, the water, and the atmosphere. Abrasion depends upon the frequency, duration, and the velocity of flow, and the character and amount of bedload. i.04 Protective Coati% s and Linings: Protective coatings for corrugated steel pipe snailcon orm to Section 66 of the Standard Specifications. Plastic (asphalt mastic or polymeric) coatings are acceptable coatings for non-abrasive flow conditions on the inside of the pipe. Paved invert lining shall be applied on all steel storm drain facilities. Invert lining may be required for metal pipes subject to excessive wear from abrasive flows. All lining material shall conform to the Standard Specifications. 14 COUNTY OF wa N B E swwsrwrO T R A N S P O R T A T I O N D E P A R T M E N T STANDARD SPECIFICATIONS SECTION 1. DEFINITIONS AND TERNS SECTION 4. SCOPE OF WORK SECTION 5. CONTROL OF WORK SECTION 6. CONTROL OF MATERIALS SECTION 1. LEGAL RELATIONS AND RESPONSIBILITY SECTION 8. PROSECUTION AND PROGRESS SECTION 9. MEASUREMENT AND PAYMENT SECTION 10. DUST CONTROL SECTION 15. EXISTING HIGHWAY FACILITIES SECTION 19. EARTHWORK SECTION 24. LIME TREATMENT SECTION 25. AGGREGATE SUBBASES SECTION 26. AGGREGATE BASE SECTION 38. ROAD MIXED ASPHALT SURFACING SECTION 39. ASPHALT CONCRETE SECTION 51. CONCRETE STRUCTURES SECTION 66. CORRUGATED METAL PIPE SECTION 73. CONCRETE CURB, SIDEWALKS AND DRIVEWAYS jv` d7b SECTION 66. CORRUGATED METAL PIPE 66(a) General Corrugated metal pipe shall conform to the provisions in Section 66 of the Standard Specifications and as hereinafter specified. 66(b) Materials Materials for corrugated metal products shall conform to the latest provisions of the Standard Specifications, except that, when approved and shown on the improvement plans, aluminum corrugated metal pipe may be used outside the roadbed when the flow and soil conditions meet the minimum criteria as set forth in the latest provisions of Section 7-821 of the State Division of Highways Planning Manual, Part7-Design, for a service- life of 25 years. 66(c) End Finish The ends of 0.060 inch and 0.075 inch thickness installations which are not fully protected by concrete structures or flared ends shall be reinforced in accordance with the provisions of Subsection 66-3.04 of the State Standard Specifications except that it shall not be.neces- sary to specify this on the plans. 66-1 ic.i IJP6 California Test 643 STATE OF CAUFORNIA-USINESS, TRANSPORTATION AND HOUSING AGENCY November 1999 DEPARTMENT OF TRANSPORTATION p ENGINEERING SERVICE CENTER Transportation Laboratory 5900 Folsom Boulevard Sacramento, California 95819-4612 METHOD FOR ESTIMATING THE SERVICE LIFE OF STEEL CULVERTS CAUTION: Prior to handling test materials, performing equipment setups, and/or conducting this method, testers are required to read "SAFETY AND HEALTH" in Part 6 of this method. It is the responsibility of the user of this method to consult and use departmental safety and health practices and determine the applicability of regulatory limitations before any testing is performed. A. OVERVIEW Two environmental factors are combined for estimating the service life (years to perforation) of steel culverts. These factors are the hydrogen -ion concentration (pH) and the minimum electrical resistivity of the site and backfill materials. The pH of soil or water Indicates the degree of acidity or alkalinity, while the minimum resistivity indicates the relative quantity of soluble salts in the soil or water. Using these parameters, the probable maintenance -free service life of a galvanized steel culvert in a given location can be estimated by using the chart shown in Figure 1. This information. combined with a condition survey of existing culverts, if any, provides a basis for. (1) estimating the maintenance -free service life of galvanized steel culverts and (2) estimating the additional life that would be obtained by coating the culverts with a dielectric material to reduce their corrosion rate. The years to perforation is not the total useful service life of culverts. It is a common point at which it is likely that maintenance fonds could be spent to repair corrosion damage. -1- This test method is divided into the following parts: 1. Method of Field Resistivity Survey and Sampling for Laboratory Tests. 2. Method of Determining pH of Water. 3. Method of Determining pH of Soil. 4. Laboratory Method of Determining Minimum Resistivity, 5. Estimating The Maintenance -Free Service Life of Steel Culverts from Test Data. 6. Safety and Health. This test method refers to the following other California Test Methods: California Test 201 (Method of Soil and Aggregate Sample Preparation), California Test 202 (Method of Tests For Sieve Analysis of Fine and Coarse Aggregates), California Test 417 (Method of Testing Soils and Waters For Sulfate Content), and California Test 422 (Method of Testing Soils and Waters For Chloride Content). PART 1. METHOD OF FIELD RESISTIVITY SURVEY AND SAMPLING FOR LABORATORY TESTS E. SELECTION OF SOIL SAMPLES FOR LABORATORY TESTS 1. Take sufficient field resistivity measurements at various locations in the channel or culvert sites to adequately represent the soils of these areas. 2. If the field resistivity measurements are reasonably unifunn within the limits of the site, soil samples from three different locations should be selected for the laboratory tests. If, however, some locations have field resistivities that differ significantly from the average of the field resistivities for the areas being surveyed, additional soil samples should be taken to represent these locations. particularly those with field resistivities significantly below the average. a. For example, if the field resistivities throughout the surveyed area are all at or near an average value of 2000 ohm -cm, three samples will be sufficient- If any of the locations tested have field resistivities markedly below this average, for example 800 ohm -cm, then additional samples should be taken to represent these "hot spots". Scattered locations of higher resistivity, for example, 3000 ohm -cm or more, do not require additional samples. b. Judgment must be exercised during field testing and sampling to secure representative samples. c. In all cases, do not take less than three laboratory samples. See NOTE 1. F. PRECAUTIONS In field testing and sampling, carefully follow these instructions and also the manufacturer's instructions for use of the resistivity meter. NOTE is When selecting a sample for the minimum resistivity and pH tests using the large soil box, take a sample that will yield 1.6 kg of material passing the 2.36-mm sieve. When -3- California Test 643 November 1999 selecting a sample for the minimum resistivity and pH tests, using the small soil box, take a sample .that will yield 500g of material passing the 2.36-mm sieve. If field resistivity measurements approach 1000 ohm -cm, take a sample that will yield 2.3 kg of material passing the 2.36-mm sieve. This amount of soil will provide sufficient material for the minimum resistivity (for either the large or the small box), pH, sulfate (SOC) and chloride (CI-) tests. The measurement of the sulfate content (California Test 417) and the chloride content (California Test 422) are required when the laboratory minimum resistivity is less than 1000 ohm - cm. These data are used for evaluating the chemical effect of the environment on reinforced concrete. NOTE 2: Field resistivity .test data can not be used for estimating service life of steel culverts. PART 2, METHOD OF DETERMINING pH OF WATER SCOPE This method is suitable for laboratory or field determination of the pH of water samples. A. APPARATUS AND MATERIALS 1. A pH meter shall be suitable for either field or laboratory analysis. 2. A 50-mL wide mouth beaker or other suitable glass container is required. 3. Various pH standard buffer solutions of known pH values are required. They include: pH values of 4.0, 7.0 and 10.0. B. RECORDING DATA Record.test data in a field notebook or use an appropriate form. C. METHOD OF SAMPLING 1. Dip a clean, wide -mouth beaker into the water to be tested. Swirl to rinse and pour D. STANDARDIZATION OF pH METER Follow the instructions provided by the manufacturer. E. USE OF pH METER TO DETERMINE pH OF THE SOIL Follow the instructions provided by the manufacturer. Measure and record the pH to the nearest tenth (0.1) of a unit F. PRECAUTIONS NOTE 4: Thoroughly stir soil sample with the glass rod immediately before immersing the electrode(s) into the soil slurry solution. Place the electrode(s) into the soil slurry solution (NOT THE SOIL) and gently move the beaker or container to make good contact between the solution and the electrode(s). NOTE 5: If the pH reading is unstable when the electrode is immersed in the soil slurry solution, leave the electrode immersed until the pH reading has stabilized. In some cases. it may take as long as 5 min to stabilize the pH reading. 1219wX-3 If the pH meter being used does not have a temperature compensation feature, or the temperature of the environment is not controlled, temperature corrections must be made. The simplest method to achieving this is to standardize the pH meter with the meter and the standard buffer solutions at the same temperature as the test sample. PART 4. LABORATORY METHOD OF DETERMINING MINIMUM RESISTIVITY SCOPE This method describes the procedure for determining the mi dmum resistivity of a soil or water sample selected as indicated in -5- California Test 643 November 1999 PART 1. These minimum resistivity values are used to estimate the Fife of a culvert, as described in PART 5, A. APPARATUS AND MATERIALS I. The resistivity meter shall be an alternating current (AC) system or a 12-V direct current (DC) system with a Wien Bridge (AC bridge), a phase sensitive detector and a square wave inverter to produce a nominal alternating signal at 97 Hz. See Note 7. 2, The soil box (large or small) shall be calibrated for use with the resistivity meter. See Figure 2 for details of the large soil bar and Figure 3 for details of the small soil box. See Note 10 for the method for calculating the large soil box constant. See Note 14 for the method for calculating the small soil box constant _ 3. Various resi30.;.; are required. They include: 100, 200, 300. 500, 700. 900, 2000, 3000, 5", 10000, and 20000 (nominal value, 1 % precision). 4. A 2.36-mm sieve shall be used (Note: refer to California Test 202 for specifications). 5. Round mixing parts are required. They shall be non -corroding, such as plastic or stainless steeL They should be approx- imately 300 min in diameter with a depth of 50 mm 6. A spatula is required for mixing materials. 7. An oven is required: however, at no time may the temperature exceed 60°C. As a practical operating range, the oven should be maintained at 45 t 15°C. 8. A scale or balance shall have a capacity of 5 kg with an accuracy of 1 g. 9. Distilled, deionized or other clean water shall have a resistivity of 20 000 ohm -an or greater. 10. A graduated cylinder is required with capacity of 100 mL, or larger. deionized or other clean water in lieu of the 150 mL specified in Step 3. Continue to add water in 50-mL increments followed by mixing. placing in layers, compacting, measuring the resistance and calculating the resistivity until the minimum resistivity has been reached. Once the minimum value has been reached. additional increments of water will cause the resistivity to increase. 11. Record the amount of water added, resistance measurements and the calculated resistivity values for each of the above steps. The mirtitnum resistivity determined in this test is the lowest electrical resistivity for this soil at any moisture content and is therefore the worse case condition. The minimum soil resistivity value should be reported in standard units of ohm -cm. 12. The Minimum Soil Resistivity, using standard units and the typical large soil box, is calculated as follows: Minimum Soil Resistivity, ohm<rii = [m§mulen resistance reading (ohm)] x [6.76 on typical large soil box constant] NOTE 7: Most resistance meters or volt -ohm meters without an inverting circuit allow the sample under test to polarize during measurement causing the reading to vary (i.e., drift). The meter should have four connections. One pair is located on either side of the meter. Each pair of connections must be wired in parallel with two wires attached to the stainless steel machine screws on either side of the large soil box. NOTE 9: In some soils, the minimum soil resistivity occurs when the specimen is in a slurry condition. When this occurs it is necessary to thoroughly mix the soil slurry and then -7- California Test 643 November 1999 pour the soil slung into the large soil box until it is full. If the soil box is not full using this procedure, add enough of the mixed soil to the soil box until it is filled and take the reading. NOTE 10: The multiplying constant for each Large Soil Box is derived as follows: Constant for Typical Large Soil Box (See Figure 2) 1t55mmx0.lan/nm)(45mmxolan/nanl =6.76 an (1032 mm x (I1 cm/mm>) MEASURING THE MINIMUM RESISTIVITY OF A SOIL SAMPLE USING THE SMALL SOIL BOX 1. Thoroughly clean the mixing pan, spatula and small so0 box with distilled, deionized or other clean water for each new sample, 2. Quarter or split out about 130 g of the material passing 2.3Emm sieve. Refer to California Test 201, -Method of Soil and Aggregate Sample Preparation", for details. 3. If the sample has been dried, add about 15 mL of distilled, dekinized or other clean water to the 130 g of soil and thoroughly mix if the sample has not been dried, skip to Step 10, 4. When the soil sample is thoroughly nibad place the sample in the small sod box in layers and compact each layer by hand. Compact the material as densely as possible into the soil box using moderate effort with the fingers. For sticky, clayey soils. the use of a spatula Is permitted for initial compaction. Continue this procedure for succeeding layers to maintain a uniform density with mirmrtal voids. Trim the excess material flush with the top surface of the soil box using a straight edge. 5. Measure the resistance of the soil in accordance with the instructions furnished by the manufacturer with the resistivity meter. Calculate the resistivity of the soil_usingthe small 3. If the distilled, deionized or other clean water in the soil box measures infinite resistance (resistivity greater than 20 000 ohm -cm if other clean water is used), empty the soil box of water, fill with the test water, measure its resistance in accordance with instructions furnished by the manufacturer with the resistivity meter, calculate its resistivity using the soil box constant and record the resistivity. 4. If the distilled, deionized or other clean water in the soil box measures less than infinite resistance (or resistivity less than 20 000 ohm -an for other clean water), continue to rinse with distilled, deionized or other clean water until the soil box is absolutely clean. This condition is Indicated by an infinite resistance measurement (or resistivity greater than 20 000 ohm -an fur other clean water), when the box is filled with distilled, deionized or other clean water respectively. H. RECORDING DATA Record data In a notebook or use an appropriate form. 1. PRECAUTIONS The soil box must be completely filled (level to the top). PART 5. ESTIMATING THE MAINTENANCE - FREE SERVICE LIFE OF STEEL CULVERTS FROM TEST DATA A. CALCULATIONS Using the minimum resistivity and the pH values of the soil or water obtained as described in Parts 2, 3, and 4, determine the estimated Maintenance -Free Service Life (years to perforation) from the chart shown in Figure 1. This value is the estimated years to perforation for an 18 gage steel culvert having a galvanic coating of 605 g/mz of zinc, in the environment represented by the test samples. A factor for each steel thickness is listed in the table in Figure 1. To determine the years to perforation for a greater steel thickness, multiply the factor for that gage by the years -9- California Test 643 November 1999 to perforation obtained for an 18 gage steel culvert. B. REPORTING District reports which include an evaluation of the data obtained from tests and condition surveys of existing culverts, and test data, shall be made and the results noted in the District Materials Report or Geotechnical Design Report. The Materials Report or Geotechnical Design Report should also include recommendations for available alternative culvert materials. NOTE 15: The actual performance records of existing culverts in similar environments provide the most valuable information concerning culvert life for a specific site. Where such data are available, they should take precedence over the test method data for estimating the years to corrosion perforation. NOTE 16: A computer program is available to aid in the selection of culvert materials. For information contact the Transportation Laboratory (Corrosion Technology Branch). REFERENCES L Field Test for Estimating Service Life of Corrugated Metal Culverts. by J. L. Beaton and R. F. Stratfull. Pmc. Highway Research Board Vol. 41, p. 255. 1962 2, Field Method of Detecting Corrosive Soil Conditions. by R. F. Stratfull. Proc. 15th CaLif Street and Highway Conference, held at UCLA, Jan. 24-26, 1963 ITTE p. 158. 3. Comparison of Caltrans' Standard Soil Box Minimum Resistivity to the Small Soil Box Minimum Resistivity. by T. B. Kennelly, State of California, Department of Transportation. Engineering Service Center, Division of Materials Engineering and Testing Services, November 1999, 0 00 0 0 0 0 YEARS TO PERFORATION-18 GAGE STEEL CULVERT 6 DD 8 �. •�8- --. :+®® 88 �� _ __�"►��► m = ma m-n D0 1� om Zcl) o 1-4 mZ rQ nm m can° Uo OP VIE 64.5 mm E E v N Plastic Material - 4 Mm thick STAINLESS STEEL Bottom -1 piece (83.7 mm long by 33A mm wide by 4 mm thick) Sides - 2 pieces ( 83.7 mm long by 25.4 mm wide by 4 mm thick) R004 2� END VIEW Electrodes - 2 pieces of stainless steel (25.4 mm tong by 25.4 mm wide by 9.6 mm thick) All screws and fasteners - stainless steel FIGURE 3 - SMALL SOIL BOX FOR LABORATORY MINIMUM RESISTIVITY DETERMINATION 5 GA. STRUCTURAL STEEL PLATE should not be compared to ....CC MM4Mn 5 GA. IS 0.218 IN. THICK ISOWIX. iN x 5 GA. STRUCTURAL STEEL PLATE is 0.218 inches thick while 18 GA. Corrugated Steel Pipe is only 0.052 inches thick. The title information appearing at the top of the page, complete with comparably sized fonts for the two materials, was provided to establish a strong visual representation to the significant difference in the size of the material. The solid black lines shown above precisely represent their respective thicknesses. Comparing 5 ga. Structural Steel Plate material to 18 ga. Corrugated Steel Pipe is like comparing a 218 pound NFL linebacker to a 52 pound third grader in Pee Wee football. Both are human and both play football, but there's a big difference is size and strength. One square foot of 5 gauge Structural Steel Plate weights 8.9 pounds One square foot of 18 gauge Corrugated Steel Pipe weights 2.1 pounds These two materials should not be lumped together and compared on equal terms with respect to performance simply because they: 1. Both use the same cathodic protection method, and 2. Both use a corrugated scheme for structural strength The performance of these two materials is significantly different because of the difference in their size and strength, and ...... the most highly recognized authorities in the civil engineering profession such as the US Army Corps of Engineers, Federal Highway Administration (FHWA), and Caltrans authorize the use of these materials in publicly financed infrastructure. In the final analysis, the performance of 18 ga. corrugated steel pipe should not be used to judge the performance of 5 ga. structural steel plate which has proven in multiple studies to be significantly stronger and more durable. Al: Techn,col Pepart Dacum...o tion Page 1. Rreo , No. 1. Ge.e ••m en. Acu ...on Ib. 3. Rec.p,en.l C..al.g No. FHWA-FLP-91-006 A. Tole and Sub ... 1. 5. R<p m. Oa.. June 1991 Durability of Special Coatings for aCade Corrugated Steel Pipe 6. Pe,le, m,nq O,garo .o.,on R.pon No. 7. John C. Potter, Laurand Lewandowski, Dewey W. White, J . 9. P.,le,mmq O.gv,..anon Name and Add —Is 10. Wo,\ U-1 N.. (TRAIS) US Army Engineer Waterways Experiment Station Ceotechnical Laboratory I1. Con,.aa. a. G,an. No. 3909 Halls Ferry Road Vicksburg, MS 39180-6199 13. Ty pr eI R..... and P.,,.d Ca ...d 4/24/89 - 4/22/91 12. Spon.o,rnq Agency Nome and Add,*+• US Department of Transportation Federal Highway Administration 400 Seventh Street, SW Washington, DC 20590 Id, Sp.n.a„nq Agency Cede HFL-23 15. S.pplen.en,a,y No,.. 16. Ab.,,oc, This report covers a literature search and review and a limited field study to updat previous work related to corrugated steel pipe (CSP) and durability estimation (expected service life). This study, using plain galvanized (zinc coated) CSP as the base line, addresses additionalcoatings including nonmetallic (bituminous coated, bituminous coated and paved, polymers, fiber bonded, epoxy bonded and concrete lined) and other metallic coatings (aluminum -zinc (galvalume) and aluminum -coated type 2) that may be used to achieve a desired design life of at least 50 years. This study is limited to storm drainage systems carrying naturally occurring surface water only. The recommenda- tions in this report do not apply to sanitary or industrial sewers or other conduits used to carry corrosive effluents. The information collected in this study revealed that with additional coatings such as bituminous coated and paved, polymer coated (ethylene acrylic acid film) or concrete lined, under proper conditions, the expected service life of galvanized CSP can be extended to at least 50 years. A Modified California Estimation Chart which takes into account the scaling tendency of natural waters was used in the determination of the expected service life of the CSP. The scaling tendency is determined by a relationship of alkalinity plus hardness minus the free carbon dioxide (CO2) of water. 17. Key W.,d. Corrugated steel pipe, drainage, 18. p; ,.,, ba .,an S1.1 .n, o restrictions. This document is durability, service life, coating, available to the public through polymer, galvanize, aluminum, epoxy, the National Technical Information bituminous, fiber bonded, Service (NTIS), Springfield, VA concrete lined 22161 719. S.ca•„y Cf-4. (al IS- ••peed 20. S.1-1y Cla,.,l. lel .A,. peq.l 21. Na. of Poq.. 22. P,.c* Unclass ified Unclassified 61 Form DOT F 1700.7 Preface The information reported herein was sponsored by the U.S. Department of Transportation, Federal Highway Administration (FHWA) under the Coordinated Federal Lands Highway Technology Implementation Program (CTIP), Study C-1, Durability of Special Coatings for Corrugated Steel Pipe. Technical monitor for this study was Mr. Alfred Logie. This study was conducted by personnel of the Pavement Systems Division (PSD), Geotechnical Laboratory (GL) at the U.S. Army Engineer Waterways Experiment Station (WES), Vicksburg, MS. Dr. John C. Potter, (formerly of the PSD, however, since January 1990, affiliated with the U.S. Army Corps of Engineers, Huntsville Division, Huntsville, Alabama) conducted a limited field study of corrugated steel pipe installations. The literature review was conducted and report prepared by Dr. Potter, 1st Lt. Laurand Lewandowski, and Mr. Dewey W. White, Jr. Mrs. Jimmie Perry of the Information Management Division, Information Technology Laboratory, provided assistance in conducting the literature search. This study was conducted under the general supervision of Dr. W. F. Marcuson, III, Chief, GL. Direct supervision was provided by Mr. H. H. Ulery, Chief, PSD; Dr. R. R. Rollings, former Chief, and Messrs. L. N. Godwin and T. W. Vollor, Acting Chiefs, Material Research and Construction Technology Branch, PSD, GL. COL Larry B. Fulton, EN, was the Commander and Director of WES. Dr. Robert F. Whalin was the Technical Director. iii AT - ,I Er 0. _/ ; � \ l: c % ; � I 0 \ f / K} \ az; /§�: § ( \ ® a m m = % _ _ ! ) 2 ! _ ) \ `§§( • !i $}3 f!($ ( *£! - ,! !§i,! w 0 ! _ g SS C: • 3 7z%!I ; u ° Izlf 333 3 > , 2 4 2« , 0 . ;{t! I !2 !}/ {;ƒƒ !!£ƒ 0 e " && f! ° " } G ! 0 ; $ ! 2 , < r f m \5 :m e =n!! q f! k 0 ° k e EL o TABLE OF CONTENTS Pa Pe I. INTRODUCTION ................................................. 1 A. Background ............................................... 1 B. Objective ................................................ 1 C. Scope. ......... ...... ............................ 1 D. Approach ................................................. 2 IT. LITERATURE REVIEW ............................................ 3 A. Sources .................................................. 3 B. Results ................................................... 3 III. CORROSION MECHANISMS, PARAMETERS AND DURABILITY PREDICTION... 4 A. Background ............................................... 4 B. Types of Corrosion ....................................... 4 C. Carbonate Saturation Phenomenon .......................... S D. Constituents Role in the Corrosion/Scale Formation on Metal Surfaces in Natural Waters ...................... 6 E. Durability Prediction Methods ............................ 11 IV. FIELD STUDY .................................................. 18 A. Sites Visited During This Study .......................... 18 B. Summary ...................................... . .. ........ 27 C. Sites Visited Prior To This Study ........................ 29 V. PROTECTIVE COATINGS FOR CORRUGATED STEEL PIPE ................ 38 A. Nonmetallic .............................................. 38 B. Metallic ................................................. 40 VI. DURABILITY ESTIMATION (EXPECTED SERVICE LIFE) FOR GALVANIZED CORRUGATED STEEL PIPE ............................. 42 A. Procedure ................................................ 42 B. Example .................................................. 43 VII. CONCLUSIONS AND RECOMMENDATIONS .............................. 46 A. Conclusions .............................................. 46 B. Recommendations .......................................... 46 REFERENCES.................................. ............... 47 APPENDIX A: BIBLIOGRAPHY .................................... Al v DURABILITY OF SPECIAL COATINGS FOR CORRUGATED STEEL PIPE I. INTRODUCTION A. BACKGROUND The design life for corrugated steel pipe (CSP) desired by many state and Federal agencies is at least 50 years. In an effort to achieve this expected service life (durability), a number of items need to be taken into considera- tion. Included are the structural requirements (which are not covered in this report) and corrosion mechanisms and parameters. The latter includes the chemistry and electrical conductivity of the soil and water in contact with the CSP and the bedload (soil, rock, debris, etc.) which may flow through the CSP during the life of the CSP. Various protective coatings may be added to the CSP when the proper conditions (chemistry and bedload) are present to provide add -on years to achieve the desired estimated service life of at least 50 years. The Federal Highway Administration (FHWA), under the Coordinated Federal Lands Highway Technology Implementation Program (CTIP), sponsored this study to develop a durability estimation procedure for CSP with various protective coatings to obtain a 50-year desired design life. B. OBJECTIVE The objective of this study was to develop a procedure for durability estimation (expected service life) of CSP having various nonmetallic and metallic protective coatings. C. SCOPE This study, using plain galvanized (zinc coated)"',i8)^ CSP as the base line, addresses additional coatings including nonmetallic (bituminous coated, bituminous coated and paved, polymers, fiber -bonded, epoxy bonded and concrete lined) and metallic coatings (aluminum -zinc (galvalume) and aluminum - coated type 2) that may be used to achieve a desired design life of at least 50 years. This study is limited to stcrm drainage systems carrying naturally occurring surface water only. The recommendations in this report do not apply * See reference section at back of report 1 to sanitary or industrial sewers or other conduits used to carry corrosive effluents. U. APPROACH A literature review of documented research pertinent to the field performance of CSP and proposed methods to predict service life, and a limited ; eld study of CSP installations, were conducted to update previous studies. The results from this review and study were used to develop a procedure for estimating the service life of CSP with various protective coatings. 2 I1. LITERATURE REVIEW A. SOURCES Several searches of literature data bases were conducted through the U.S. Army Engineer Waterways Experiment Station (WES) Information Technology Laboratory. These included: 1. COMPENDEX PLUS. Engineering Information, Inc., New York, NY. 2. METADEX. ASM International, Metals Park, OH and Institute of Metals, London, England. 3. NTIS. National Technical Information Service, US ➢epartment of Commerce, Springfield, VA. 4. TRIS. US Department of Transportation and Transportation Research Board, Washington, DC. A search conducted in the WES technical library produced additional references. A list of the documents selected for review from the various databases and WES library is given in Appendix A. B. RESULTS Applicable information was selected from the literature review. References are made throughout the report to this information with a listing in the reference section. The review included work conducted and published by engineers, researchers, and state and Federal agencies. Corrosion mechanisms and parameters are discussed and the effect of soil and effluent chemistry on the corrosion rate is also elucidated. A method to predict service life of GSP based on the characterization of the severity of the service environment and field performance studies is presented. 3 III. CORROSION MECHANISMS, PARAMETERS AND DURABILITY PREDICTION A. BACKGROUND Corrosion is the major problem observed in pipe durability worldwide, causing almost 15 billion dollars worth of damage yearly.1��1 Corrosion is the dissolution of or destructive attack on a metal or its properties by a chemical or electrochemical reaction with the surrounding environment.("9 Failure or penetration of the CSP is usually the main effect of corrosion. Often, corrosion will work synergistically with other processes to produce greater deterioration than it would alone. One of these processes is erosion or abrasion which is the gradual wearing away of material by water carrying sand, gravel, etc. Erosion, alone, is usually not a factor unless the pipe is on a slope and exposed to high velocity water flows (>15 feet per second). Other processes include impingement and cavitation, but these rarely effect the pipe as much as corrosion. B. 'TYPES OF CORROSION In the corrosion of CSP, there are two types: soilside and waterside corrosion. It has been found that most metal loss associated with corrosion occurs on the interior or waterside of the pipe.1,13.25.29.45,]9) soilside corrosion is complex but usually is not a significant factor in pipe life except in very arid, sandy regions where rainfall is minimal."'-'9j Emphasis in this section will be placed on waterside corrosion with soilside corrosion referred to under certain circumstances. Metals, when immersed in water, tend to corrode because of their thermo- dynamic instability."" In the presence of oxygen and water, the metal corrodes through an oxidative process that involves the formation and release of metallic ions. The water acts as an electrolyte to carry these ions which form the basis for the corrosion of the metals.") The reaction of the metal, with the dissolved oxygen in the water, causes the deterioration most visible on the waterside of the pipe. Pipe manufacturers have found ways to inhibit the corrosion of pipes by using ceatings("� such as asphalt, fiber bonded films, polymer films, concrete cement, zinc, aluminum -coated type 2, and aluminum -zinc (galvalwne). These coatings may be applied to pipes made of steel, iron and aluminwn. All these methods have met with varying degrees of success, but the natural scaling 4 tendencies inherent to some waters provide the best protection. Scaling is the deposit and adherence of insoluble products on the surface of the pipe which isolate it from the water and hence protect it from corrosion. The factor most affecting corrosion and scale formation in the pipe is the chemicals dissolved in or transported by the natural waters.122) The chemical mechanism which leads to scale formation will be discussed in the following paragraphs. C. CARBONATE SATURATION PHENOMENON Tillmans, in his earliest work,("3 found that in natural waterscontaining oxygen, calcium carbonate was the salt most useful in the formation of scales or a natural protective film. In later work, he developed an equation relating the pH of the water to the total alkalinity and free carbon dioxide (CO2). He used the following relationship: Free CO2 = alkalinity/antilog (pH - 6.31) EQ. 1 where alkalinity as calcium carbonate (CaCO3) and free CO2 are expressed in parts per million (p.p.m.). Others have investigated carbonate saturation phenomenon to formulate mathematical answers and practical applications. Baylis1sl looked at carbonate saturation by measuring the pH and total alkalinity, but failed to accurately describe the system because he neglected the calcium content. Langelier was the first person to analytically describe this relationship in the interior of steel or iron pipes in contact with water. The approach Langelier used was to derive a relationship between the pH of the water and its total alkalinity and calcium content as shown below:016 pHs = pCa + pAlk + (pK2 - pK,) EQ. 2 where pHs is the calcium carbonate saturation pH, pCa is the negative logarithm of the calcium concentration expressed in p.p.m. of CaCO3, pAlk is the negative logarithm of the alkalinity as determined by methyl orange titration and expressed in p.p.m. of equivalent CaCO3, pKZ is the ionization constant of HCO3-, and pKs is the solubility product of CaCO3.160) There are several assumptions which are made when using this equation. First, the 5 relationship was originally established for water treatment systems where the pH falls between 6.5 and 9.0. There is a possibility that pH values over 9.0 or under 6.5 will be observed in drainage systems. This, and also high salinity, will affect the accuracy. The term (pK2 - pKj from EQ. 2 is commonly referred to as the saturation index or SI. The saturation index is the difference between the actual pH of the water and the pH at the point of calcium carbonate saturation. A positive SI would indicate that the solution is supersaturated in calcium and the CaCO3 (calcite) will precipitate, while a negative SI shows that saturation has not been reached and calcium carbonate formation is prevented. There are several factors which were not considered in any of these approaches such as the effect of scale inhibiting ions, temperature, resistivity and variations in the water chemistry due to climate. In the following paragraphs, the effect of these water constituents on scale formation will be examined, D. CONSTITUENTS ROLE IN THE CORROSION/SCALE FORMATION ON METAL SURFACES IN NATURAL WATERS Most CSP carry water which contains dissolved gases, mineral constituents, organic matter, and microbiological organisms. Combinations of these components plus temperature, pH, resistivity, and climatic conditions give water its unique chemistry. The basic components of natural water are water (HZO), carbon dioxide (Co,), carbonic acid (H2CO3), ions of hydrogen (H+), hydroxide (OH-), bicarbonate (HCO3-), carbonate (Co,-2) and calcium (Ca 12),(16) These components are involved in a series of reactions listed below: K, (CO2) + (HZO) (H2CO3) Reaction A Ke (H2CO3) (H+) + (HCO3-) Reaction B K� (HCO3') (H+) + (CO3 z) Reaction C (Ca'2) + (CO3-2) - (CaCO3) Reaction D (Ca+') + (HCO3-) (CaCO3) + (H+) Reaction E (H20) + (CO,) + (CaCO3) - Ca(HCO3)2 Reaction F Under certain circumstances, solid calcium carbonate will precipitate as a result of reaction.D or Ef3`) and form a protective hydrous oxide film with 5 small quantities of magnesium. This film is only 50-100 angstroms thick but is extremely stable. If damaged, it repairs itself instantaneouslv.lnl McCauley and others have studied the protection afforded by calcium carbonate and found that it inhibits the corrosion process. (39,61) Natural water is often classified by its hardness, reported as parts per million (p.p.m.) of CaCO3. For example, waters with less than 50 p.p.m, of CaCO3 are considered soft, while waters above 350 p.p.m. are considered very hardsolubility of calcium carbonate in water depends on alkalinity, carbon dioxide, and the pH of the water. The interaction between CO2, alkalinity, and hardness controls the tendency for natural waters to form scales. Hardness (Ca'2, Mg'2) and alkalinity (HCO3-, H2CO3, CO3-2, OH-) are primarily present in the form of Ca(HCO3)2 (Reaction F), which is the main source of the CaCO3 that precipitates and forms scales on the interior of the pipe (7). Carbon dioxide is also required in the right concentration for the calcium carbonate to precipitate. The amount of carbon dioxide dissolved in the rater depends on the atmospheric partial pressure in the pipe and can often be the controlling factor in whether or nor CaCO3 precipitates. (IS) Any small amount of unreacted or free CO2 above that required to stabilize the HCO3- and C032 in solution makes the water more corrosive because the free CO. dissolves CaCO3.(31) A relationship can be derived from the reactions A-C and some physical rate constants to show free CO2 as a function of HCO3- and pH. First, the formation of carbonic acid in Reaction A leads to two dissociations of H2CO3: Reaction B and Reaction C. By taking the equilibrium rate constants Ka, Kb, and K, the rate constants for the first and second dissociations can be found. K1 = Kb / Ka EQ. 3 K2 K, / Ka EQ. 4 where K1 and K2 equal 4.45 x 10-' and 4.69 x 10-11 at 25' C, respectively.(11,211 A valid assumption can be made when comparing the two rate constants, that K, is the dominant dissociation constant, i.e., HCO3- concentration in solution is much greater than CO, -?By substituting in the equilibrium rate constants N in the form of products over reactants, another expression for K3 can be produced. K1 = [ki+] [HCO3'] / [HZCO31 + [CO2] EQ. 5 Next, by assuming the carbonic acid concentration is negligible in comparison to the CO2 concentration and rearranging the terms the following expression is derived: K1 / jH+] = [HCO3-] / (CO2) EQ, 6 Then by using the log and further rearranging and then taking the antilog, a relationship is established for CO2 as a function of pH and HCO3-, JCO,j = [HCO3-j / antilog (pH - 6.22) EQ, 7 EQ. 7 is the same as EQ. 1 developed by Tillmans (]1). If organic acids from decaying vegetation or inorganic acids react with the HCO}-, the carbonate product is replaced by corrosive acid salts. It is evident when looking at hardness, alkalinity, and CO2 content, that increases in alkalinity and hardness promote scale formation while free CO, increases inhibit scale formation. `7) The pH is the most common index used to study the corrosivity of water systems. By definition the pH is the negative logarithm of the hydrogen ion concentration. Most waters have a pH range from 5.5 to 9.0 independent of location.(22.26.7<) Pipe waters which have a pH below 5.5 are highly acidic.(22) McKee and Brown have shown with various chemical solutions that the corrosion rate as measured from metal loss is independent of pH within the range of 4 to 9."'1 Stumm observed a general trend of increased corrosion rates with an increase in pH from 6.9 to 8.6.1123 The water pH is an indicator of the amount of atmospheric carbon dioxide in equilibrium with the solution.(25) It acts in the same way as excess CO,; if the pH is low due to high acid content, the water becomes more aggressive towards scale formation. M Other components of natural waters are ions, mainly calcium, magnesium, sodium, bicarbonate, sulphate, phosphate, chloride and nitrate. The presence of sulphate and chloride ions can either disrupt or prevent scale formation.(25) It has been observed that 100 p.p.m. bicarbonate in water containing 2-100 p.p.m. chloride ions will have little influence on corrosive attack on the metal film.(25) Larson and Skold found that in domestic waters, the ratio of bicarbonate to chloride is the primary factor in the corrosion of water at pH's from 7 to 8.c331 They also observed that an increase in chloride content caused higher corrosion rates.C331 Sulphate ions have been known to increase corrosion rates even higher than a similar amount of chloride.(60) Lowe and others witnessed an increased corrosive attack on bare aluminum by sulphate ions when the pH drops below 4.(36) Nitrate and phosphate also have been found to act as inhibitors to scale formation.1611 Temperature and decreased resistivity also play a role in corrosion. The rate of corrosion increases as the environment changes to lower resist ivities.(30) Most resiscivities are over 2000 ohm -cm. Temperature is important in determining reactivity and solubility of the component in natural waters. Ion concentrations that make up the total alkalinity vary considerably with temperature while the total alkalinity content stays constant."') Dye proved this in his experimental work in which he measured free CO2, hydroxide, carbonate and bicarbonate concentration over a range from 0 to 100 p.p.m. and pH from 6 to 12 (See Figure 1)."'1 All these ions have their origin in the environment around the runoff area and that is why climate, rainfall and vegetation are important in determining the water chemistry. The chemical environment at a specific site is directly influenced by climate, vegetation, soil, and rainfall."'b The most important of these is rainfall because rainfall controls the chemistry of the effluent by determining the amount of minerals that are leached from the soil in the form of soluble and partially soluble salts.") When the soils are leached, their runoff is soft and acidic. This type effluent can lead to perforation of a 14 gauge galvanized pipe in the high water zone in 15 years.1b7 Vegetation is also important because warm climates accelerate plant metabolism with subsequent accelerated plant decomposition and generation of organic acids and CO2.(a1 Any method used to predict the durability of pipe should include the factors mentioned above. M 10.D 95 a 9.0 8.5 80 32 30 a a 28 z 0 6 z z w U L 4 U U 2 0 0 I BICARBONATE, CHC0-1 I I CARBONATE, 2(CO3-2) HYDROXIDE. I COH-1 FREE CO, 10 20 30 40 50 60 70 80 90 100 T EMPERATURE,C° Figure 1. Variation of pH, free CO, and three forms of alkalinity concentrations (C0H-], CCO,-' ], CHCO;]) of various temperatures"51 10 E. DURABILITY PREDICTION METHODS Historically, there have been numerous approaches taken and methods developed to predict the performance of CSP. A review of these efforts indicates that certain basic criteria must be defined and quantified. The following is required in the development of such a method: 1. The service life and/or failure criteria must be defined in some quantifiable property, i.e. loss of mechanical properties, pitting depth, loss of coating etc. 2. A measured rate of change of the parameter must be determined with time to develop a rating system to predict remaining service life. 3. The corrosivity of the field environment must be characterized by the effluent water chemistry or the soil side parameters, i.e, pH, resistivity, etc, and then correlated with field performance. 4. The developed method must be validated by field exposures in different environments with periodic inspections and ratings-'2') Another approach which has been used to predict the durability of CSP is to accelerate the corrosive attack on the pipe through laboratory test.(") Examples of these methods are: ASTM B117 Salt Spray (Fog) Testing, and ASTM D1654 Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments. However, performance in these accelerated corrosion environments may not accurately model field performance. Several unique methods have been created to study pipe durability. Schwerdtfeger displayed the usefulness of polarization curves in determining corrosion rates on the exterior or soil side of culverts."" Lindberg then used this method to estimate corrosion of full-sized metal culverts installed under highways.�"1 Virginia and Kentucky used methods based largely on PH.(22) Alabama used pH, resistivity, dissolved oxygen, and flow conditions, to predict durability."') The discussion above shows that long term metal loss is associated with the chemical and environmental conditions. By analyzing the alkalinity, hardness, pH, CO, soluble salt content and conductivity, accurate predictions of a pipe's service life can be made. Georgia's Department of Highways established a system based on point counting of hardness, acidity, CaCO3, conductance, chlorides, sulfates, and industrial waste contributions.c"I The 11 Y New York Department of Transportation used a rating system which considered corrosiveness, abrasiveness, flow rate, and environment. The corrosiveness rating included measurements of soil type, pH and water hardness."" They were also able to geographically divide the state into five regions based on corrosiveness. This was correlated with a later corrosion metal loss rate study for steel culverts in the same state.t63 Colorado and Wyoming based their metal loss guidelines for steel and concrete culverts on soluble salt concentrations, paying close attention to chlorides and sulphates.(") Notwithstanding all these factors, the California Method is still the most commonly used method for durability predictions. (cal The California Method uses the pH and minimum resistivity of either the soilside or the waterside to determine the service life of metal culverts.t`Z.651 In Figure 2, the chart used by the California Method displays years to perforation of 18 gauge metal culvert. A gage factor is also added so that conversion can be made between the various thicknesses of pipe. There is also an equation set up to calculate years to perforation of a pipe in environments where the pH is greater than 7.3. For example, if a pli and resistivity of 6.8 and 1,000 ohm -cm respectively was found at one location, then the time to perforation would be 15 years. The advantage of using the California Method is that it is quick and inexpensive. Some of the disadvantages include uncertainty about using the soilside or the waterside environment. This problem is usually solved by choosing the more conservative (shorter) of the waterside and soilside estimates. Another disadvantage is that the California Method fails to recognize the effect of scaling on corrosion. (') In a Louisiana study 1"t, it was observed that for environmental conditions considered moderate and very corrosive, the California Method overestimated the pipe's time to perforation. The American Iron and Steel Institute (AISI)O) has developed a chart (Figure 3) which is based on the assumption that culverts can continue to provide service until most of the invert is lost. This point corresponds to a total metal loss approximately twice that corresponding to first perforation."'' However, the assumption of usable life after perforation is only appropriate for gravity flow systems installed in .a nonerodible granular bedding. Further, a study of this issue was recently completed for the California Department of Transportation on behalf of the California Corrugated 12 O. tia S y � J � � no N O W�. nuke Z o n K n Lx > Z O N = W p J J v o J p n K G Y m o N o- z i p m V a 0 _O N y w O ¢ Y F a7 D ylJ :2 m :2 a' N Y u O ui 1 O N O O O O V a n N 163AV1D 1331S 39VD 21-NOI1V60363d O1 SL'V3A 13 0 0 0 0 0 I 19 Im O N LL � o e n o s s C � s � O O r `yS 2 y r QW \ W V = p a G ( 3 \ \ pW ui�K \ r^r \ o p 0o z o \ y 0 W, N V F X I 1 O O O O O O m O O N 133HS 1331S 03ZIN A-rVO NOIHL `NI Z90 0 SNV3A-3311 3`JVal1V 14 0 0 0 0 0 Is A Steel Pipe Association by Mr. George Tupac (1.987),(") He found that the AISI chart is appropriate for the upper 270' of the pipe circumference, but not for the invert. He recommended use of the AISI chart only when the invert is paved. Florida concluded from their field surveys that the durability of bare galvanized pipe with a pH higher than 5.9 and resistivity higher than 4,500 ohm- cm would last 25 years or longer, while in the areas where the pH is less Chan 5.9 and resistivity lower than 4,500 ohm -cm the California Method can be used to predict service life.(13) As seen from previous discussions, a method which includes scale promotion parameters along with scale inhibiting factors should be used. Bednar has developed such a method.") It considers most of the factors previously discussed. The Modified California Method(') developed by Bednar uses the interactions of three concentrations and their relationship to scaling to predict pipe durability. This method uses actual concentrations instead of negative logarithms. Figure 4 displays the Modified California Method chart. The Modified California Method is similar in design to the California Method except for a few important differences. The modified version assumes that major corrosion occurs on the waterside. The differentiation of the three primary components and their relationship to scaling are considered. Increases in alkalinity and hardness as discussed earlier generally lead to scale formation, while increases in free CO2 inhibit the formation of scales, giving us the relationship below; Alkalinity + Hardness - Free CO2 = Scaling Tendency EQ. 8 According to Dye, if the pH is below 7.5, the total alkalinity can be represented by [HCO3-2] without significant error.�237 This is evident in Figure 1 where bicarbonate concentrations are six times greater than the next largest contributor [CO3-'). Hatch and Rice have shown that the calcium ion in the form of calcium bicarbonate inhibits corrosion to a much greater extent than other ions in solution."" Now, by substituting the following approxi- mations for alkalinity and hardness and replacing free CO, with EQ. 7 in EQ. 8, a simplified expression is created.(" Scaling Tendency - IHCO3-]+fCa")-I[HCO3-]/antilog(pH-6.22)1 EQ. 9 15 I j I sd6 I ti � I I 'J � O 0 0 O O O O 0 O O O O O O O O O p O wdd 100 33dA - SS3NOb'VH • AlINFlVN7V AON3ON31 0Ni7V05 16 I O O m 0 0 0 E O 0 0 L Y o > 0 r O > U O O 0 0 co U 0 0 0 0 0 v 0 0 N 0 0 0 rq � r N O L E C p� O N a N N N O _ U O d L — U N O o N C O O w � O O Q� u d >7 O w O C O Mi On An example of how to determine these concentrations from measurements of hardness and alkalinity as CaCO3 requires further explanation. Since two bicarbonate ions are required to form one calcium bicarbonate molecule, a factor of 1.22 must be used to show the greater molecular weight contribu- tion to alkalinity of HCO}-. On the other hand, since Ca" makes up only 40 percent of the molecular weight of calcium carbonate, the hardness must be determined by multiplying CaCO, by .4. (See sample calculation in Section VI.) The Modified California Method recognizes the contribution of scaling and generally gives more liberal time to perforation estimates than those previously made,"' Since this method depends on the chemistry of the water, it represents a wider variety of environmental conditions. By analyzing the interacting effects of total soluble salt content, pH, resistivity, and components that these make up, a reliable prediction of pipe durability can be made.(79) From the preceding background discussion, it can be seen that many factors contribute to CSP corrosion. The more of these factors considered in the durability predictions, the more reliable the method. 17 IV. FIELD STUDY A. SITES VISITED DURING THIS STUDY A limited field study was conducted in May and August 1989 at several sites. During May 1989, sites in Arkansas and Mississippi were visited. New York and Vermont sites were visited in August 1989. Polymer coated galvanized CSP were located at the sites in Arkansas and Mississippi. Three sites were visited in the state of New York. Test plates with metallic and nonmetallic coatings (also aluminum plate) which had been installed in 48-inch diameter CSP were observed at the New York sites. Connected sections of CSP with nonmetallic and metallic coatings were observed at a site near Sunderland, Vermont. 1. ARKANSAS AND MISSISSIPPI SITES. The installations observed in May 1989 at the Arkansas and Mississippi sites were polymer (ethylene acrylic acid film -Dow Adhesive Film (DAF) 625) coated galvanized CSP and pipe arch (Crossett, Arkansas site only). A summary of information relative to these installations is given in Table 1. The polymer coated CSP have been in service as long as 14 plus years and were still in excellent condition. The only problem noted with the coating was at a site northwest of Hoxie, Arkansas. The 3-mil outside pipe coating was delaminating on the exposed end of the pipe. However, there was no corrosion of the pipe in the areas where the coating had separated from the CSP. 2, NEW YORK SITES. Various coatings on 2 ft. by 4 ft. test plates installed in a 48-in, diameter CSP were observed in August 1989 at three sites in New York. Sites on the Genesee Expressway (Sections 7A and 7B) between Dansville and Mount Morris and near Angelica were visited. The coatings included metallic (aluminum -zinc, zinc, and aluminwn-coated type 2) and nonmetallic (Nexon, Beth-Cu-Loy and DAF 625) and combinations of the two types. The nonmetallic coatings were polymer type coatings, and unless noted, were on galvanized steel places. Aluminum plates were also at the test sires. A summary of information relative to these installations is given in Table 2. (a) Seccion 7A. Twelve of the plates at this site were installed in October 1981(",sa,ss) with the remaining six installed in November 1988 (See 119 r• V1 m% W W F O r W W T C w a 'O 7 r a Y' Y• O C r p m rt 7 " r• L� H C G r, S C] r r• 0 0 0 r• 0 r• 0 r• o `-• p a n w m 7 7 m y IlU- x o c o N J z � E P W r C f/I O r a R in N O O c r O w S in m O O O O O O O O 3 r rt rC rC r• C Y. " m " m " m r• i< " m Ll a a a a w w ov n a o m m m m � r' W W bJ V V V V J R n m a r E M H m m n n m a w m m m m r• r O X Y. O r• 7 rt X X X % m a C n n " 7 n. 3 n n m 7,- O m m r po m w m m m m O 0 r r• S r r O- 0. X m 7 c r 7 m •n x pa i7 m m 7 r• O n m m m m r r\ n 7 7 O o w Vi 0 7 7 7 7 R 7 m 0 'O R rt M 3 m w rt n n n rQ� r n a n r 0. rt p 7 O O 7 r "t a 7 7 R rt b � rt m VI O to .-. 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E d 7 0 ry . d r•'d r r• 7 m- rn m J r' n m m 70 0 0 r• O d 't rt 7 7 - rn 0 ✓ 7 Y 7 w w m In 3 r• £ O d 0, m 7 m rt G 0 n N 7 rt R r w n F r' rn N a r• 7 d w C7 N w r•Y'rr m N N po rt w m r J J ✓• w m n Ga m 7 F M O m a 7 n w m C E m n n � rt rt N Y QQ w w rt 0 0 w m m m w n rt r w£ n d rt r m 7 r rt a 6 O M r• 'd O r r• r 7 rt r• O n n m rt n E C n m rt N m v d m .- rt d m d r m 7 O � R w n n n m o 0. v w 2 0 R n w W W m {U rt E 3 E rt rm o K R N m o m 0 N n 6 n< (7) D W m W to Ca Z [n D D n N Yrb N N \ \ ] !u m w m rt (n rt rt lD 0 F m m n O m 0 0. m O n n r ^ m N] D D C7 D O ti O O Co Z !*1 D D a N m b r-• r r r x o C 7 w w r• r m r' m 7 0` m� 6`< r• rr O r- c o m o r R 7 m N n n< m] Od n N m Po m r �< r o r' n ] w G n w G 7 0 m m m m N a a a rt ] QO N N N w ro n c n ro�vrororoD N r O 0 0 O 0 0 O r w GG rr] r w rr-�-nrw w G wv m Y E °3 3 Y• 3 3 0 '� m m m m c C] (D n m ] m m E m X 0 3 Oa n, n C n pa n n n 3 a 3 3 Y' N r N r N r Y• r- r r• 3: R N n o o n n n o n n r' n N N N N w n N n M E 0 O FT 0 0 7 0 N N N N n m r• m M W w rT G G m G r- Y• r r• m w 7 w r rt n rt R- n 7 7 7] r 33 Oa 3 C rr• r' n r' r. rpv (F Oa pa `< O n N m Po Oa m w Pa w Oa T rn w n N V G 7 n O O n 'V 'D m 'D r' 'O p0 m IT rn N m m m rn r• m w ro M - m m 3 m V 7 3 r r m r O n m N r N 7 m n N m 0 0 0 r' 0 N n n M rn b rn ] C] E rt rD N 3 rn M r rT n o 7 < R 3 rt n n rt n n G n 7 n r r m m G m 3 n N N O Y m m � TJ rt rt O n < o N 7 to Y• r• N N 7 N m 7 a N w G rt R n rt O r 3 m O N n 0 C Fn m R T G Y• m O N n S 7 N T O C ] o rt Y• n n r n o v r Po a o w N QO o w O m n ? O S n rt E ] Y• r M M r O n ] O rT rT rT r 7 rT in Po E r o r r - o n 0 E N o v r, E n E ro E N m r m r r r r n o r N r r G 7 r 7 ro E Y' R r 7 rt w n O ] N ] m m r- r 7 O m N ] m w r' O rt N n 3 N o R (U r n rn n o n C rn w o N r Iv £ rt N Qo ] O o m ] (D o o E rt 0 iE ,,r Figure 5). The plates were coated with different types or combination of coating types. (1) October 1981 Plates. The polymer coatings (Nexon and Beth- Cu-Loy) were nicked due to sharp razor -like shale bedload"" flow through the pipe. The shale bedload had been limited due to a stilling basin near the inlet of the pipe. However, the basin did not prevent all shale from flowing through the pipe. The zinc coating beneath the nicks on the polymer coated test plates N1 and B1 was not damaged. However, the zinc coating was gone on N2 and B2 and plate N2 contained rusty pits. Aluminum plate Al was nicked and stained, and plate A2 was stained. Although the aluminum -zinc coating on plates C1 and C2 was gone to the low flow line, the base metal was not pitted. The aluminum -coated type 2 plates AS1 and AS2 contained nicks to the alloy layer but no rust was present. The zinc coating was gone to the low flow line on plates Z1 and Z2. These plates were pitted but contained no perforations. (2) November 1988 Plates. These plates coated with combinations of the polymer DAF 625, contained nicks in the coating; however, no rust was present on the plates. The zinc and aluminum type 2 coatings were in excellent condition. The aluminum coating was stained. (b) Section 7B. At this site, twelve plates were installed in October 1981.sa...... ) four in October 1984'57� and seven in November 1988 (See Figure 5)- These plates were coated with different types or a combina- tion of coating types. The shale bedload was much heavier at this site since a stilling basin had not been constructed near the pipe inlet as at the Section 7A site. (1) October 1981 Plates. The polymer coatings (Nexon and Beth- Cu-Loy) were peeled to the flow lines, the zinc coating gone and the base metal pitted on plates N1, N2 and Bl. The condition of plate B2 was similar Lo the others except the base metal was only rusted. Aluminum plates Al and A2 contained nicks to the low flow line. The coating was gone on the zinc coated plates Z1 and Z2 and the plates contained perforations. (2) October 1984 Plates. All polymer coatings (DAF 625, Beth- Cu-Loy and Nexon) were blistered to the low flow line. The zinc coating on plate B3 (Beth-Cu-Loy) was intact. However, on plate BK3 (DAF 625) the base metal was pitted and rusted. The zinc coating on plate N3 (Nexon) was 23 N m n T U m ° u O U � N _ m E E n c E E O > > e p O O N N N V iA x � n a m W mi 10Y�m mIV N m � T m H T v c M U T C O O O O N J U J W J U] J O C.c U c c O z a m a a N azamowal N 0 U 24 NU) N _O Q 1 C 0) E L Q x i Ln N Y O } 3 O Z In N 7 Ll perforated. The epoxy coating on plate E3 was chipped to the high flow line and the base metal pitted and scaled. (3) November 1988 Plates. The polymer (DAF 625)- coated plates (BK/steel, BK/AS, BK/83 and BK/G) were nicked to the low flow line. The base metal on plate BK/steel was rusted. The aluminum -zinc (C), aluminum -coated type 2 (AS) and aluminum -coated type 2 (AS/83-made in 1982) plates were in excellent condition except that the AS plate was stained. (c) Angelica. Eight of the plates at this site were installed in October 1984 and the other five were installed in November 1988 (See Figure 5). This site had an aggressive bedload consisting of fossiliferous sandy limestone with many 6 to 12 in. diameter boulders.(5:1) (1) October 1984 Plates. The aluminum plate (A), aluminum -zinc (C), aluminum -coated type 2 (AS), and epoxy (E) coated plates were missing from the test site. Approximately half of the zinc coating up to the flow line had been removed on plate Z. The Nexon coating on plate N was peeled off the corrugation crests to the high flow line. The zinc coating was off the corrugation crests to the low flow line, and the crest base metal was pitted. The Beth-Cu-Loy coating on place B was peeled off the crests. The zinc coating was gone off the crests and the crests were rusty. The DAF 625 coating on plate BK was peeled off the crests to the high flow line and the crests were rusty. (2) November 1988 Plates. The aluminum -zinc (G) place was missing from the test site. The DAF 625 polymer coating on plate BK/steel was off the corrugation crests and the base metal was pitted to the low flow line. The DAF 625 on plate BKj AS was off the crests, and the aluminum type 2 coating perforated to the low flow line; however, no rust was observed. The DAF 625 coating on plate BK was off the upstream crest tangents and some of the zinc coating was gone to the low flow line. The aluminum type 2 coating on plate AS was off the upstream crest tangents to the low flow line. 3. VER,MONT SITE. Six CSP sections approximately 18 ft. long and 36 in. in diameter with various coatings were observed in August 1989 near Sunderland, Vermont (see. Table 3). These sections, connected end to end, were installed in October 19E1. The bedload at this site, which included granular materials and cobbles up to 10 in., was intermittent. The condition of the coating and pipe is given below. 25 G N o+ D N D m n n N N N w D N D w D •o w a n r o n o N < n w J m m R n n a m a H •D m N O N n O n O w m o n o n << w n w n n r m n w R C w 7 n rw r.:n vi po m 7 r J n r w o w r o r• V 7 7 J 7 rr• w 1n po w n rt 7 n w n n w o n r• w 7 r..,, J n 7 n r J 0 a m F J- o v� o rn w m r w n 7 - < r• 1� In N n 7 O J 3 w r• n m m r n r rt n v o R n m m m n O In to n F n w v rt 0 n n m m o o m r• n n o m 7 r• w In R W w R r• U r r n - r O r• r < 7 O r N N ] O �n o n r J R 7 w S m r w a n w r• w £ C m r 7 Oa n G O O S 7 7 rt m m pa r, n m m O r• < S w w J m • 3 n r n � r• m m S R J n w w o• Fn J r va n o m o 0 £ 7 n rt Ci m r N w rt Vi r 7 r m J m 7 W w n m o o m w < r n m r o 7 w w m < H 7 rt w 7 W m 7 (a) Epoxy (E). There were occasional nicks in the coating along the invert crests with localized severe blistering of the coating and rusting of metal at the 4 o'clock position near the pipe inlet. (b) Aluminum -zinc G). The coating was stained with occasional perforations through the coating to base metal. (c) Beth-Cu-Loy, (B). This coating contained occasional nicks on the invert crests. (d) Aluminum -coated Type 2 (AS). This coating was intact. (e) Zinc, (Z). The coating and base metal was severely pitted especially on the downstream tangents of the invert crests. (f) Asphalt Coated and Paved Over Zinc, (ACPZ). The asphalt paving - was intact; however, some asphalt coating was missing along the high flow line which was above the paving. B. SUMMARY The condition of the coatings, CSP and plates are summarized in the following paragraphs (see Tables 1-3). 1. ARKANSAS AND MISSISSIPPI SITES. After in-service use of 14 plus years at Arkansas sites and 8 plus years at Mississippi sites, the polymer (ethylene acrylic acid film) coated pipes were in excellent condition. The only problem noted was with a 3-mil outside coating (12 plus years service) at a site near Hoxie, Arkansas. Some of this coating which was exposed, had delaminated; however, no rusting of the pipe had occurred. Some of these CSP experienced a slight bedload (see Table 1). These CSP pipe, based on their survey condition, should continue to give years of additional service. 2. NEW YORK SITES. (a) Section 7A. The bedload(51,5'J at this site had been limited due to a stilling basin upstream of the pipe inlet. However, the condition of all plates installed in 1981 indicated that some bedload flow had occurred based on the nicks, loss of coating, pitted base metal, and overall deterioration. This deterioration would be expected to continue with all plates including the aluminum that were just stained or nicked, The zinc and aluminum -coated type 2 plates installed in November 1988 were in excellent condition. The polymer coated (DAF 625) plates contained nicks in the coating; however, no rust was visible. 27 (b) Section 7B. This site was aggressive due to a shale bedload.III ,"' The coatings had been severely damaged and the base metal of the plates (installed 1981) had begun to deteriorate. The aluminum plates were nicked with one containing pits. The deterioration could be expected to continue. The DAF 625, Beth-Cu-Loy, and Nexon (polymer type coatings installed in 1984) coatings were blistered -to the low flow line. The zinc coating was gone or perforated where the DAF 625 and Nexon had blistered. The base metal of the DAF 625 coated plate was pitted and rusty. The epoxy coated plate was chipped to the high flow line with the base metal scaled and pitted. The aluminum -zinc and aluminum -coated type 2 coated plates (installed in 1988) were in excellent condition with one of the aluminum -coated type 2 plates stained. The DAF 625 on plain steel was nicked at the low flow line with the base metal rusty. The other plates with DAF 625 and in combination with other coatings were nicked to the low flow line. However, the coatings beneath the DAF 625 were intact with no pitting or rust. (c) Angelica. Four of -the plates installed in 1984, aluminum -zinc, aluminum -coated type 2, epoxy coated, and aluminum plate, were missing from the site. The polymer (Nexon, DAF 625, and Beth-Cu-Loy) coating was off the plate crests and the zinc coating beneath these coatings was also gone with the crests rusty on the Beth-Cu-Loy and DAF 625 plates. The base metal of the Nexon plate was pitted. Approximately half of the coating on the zinc coated plate had been removed up to the flow line. Deterioration of these plates is expected to continue. The aluminum -zinc (installed in 1984) coated plate was missing. The ocher plates (polymer and aluminum -coated type 2) were damaged. The DAF 625 coating on plain steel was off the crests with the base metal pitted. The DAF 625 over the aluminum -coated type 2 coating was off the crests and the aluminum coating was perforated. The DAF 625 over the zinc coating was off the crests with approximately half of the zinc coating gone. The aluminum -coated type 2 was off the crests of the plate. 3. VERMONT. The CSP at this site had been subjected to a bedload of granular materials and cobbles up to 10 in. in diameter. The epoxy coating contained occasional nicks and was severely blistered at the 4 o'clock position near the inlet. The aluminum -zinc coating was stained and contained occasional perforations to the base metal. The Beth-Cu-Loy coating contained nicks on the invert crests. The aluminum -coated type 2 coating was in good 29 condition. The base metal of the zinc coated CSP was pitted on the downstream tangents of the crests. Some asphalt coating was missing above the high water line; however, the paving was in good condition on the asphalt coated and paved CSP. C. SITES VISITED PRIOR TO THIS STUDY. Several sites that contained CSP with various coating types as well as aluminum pipe were visited prior to this study. The results of these visits are included since they are applicable to the study reported herein. Sites visited by Dr. John C, Potter were the Natchez Trace Parkway (Alabama -July 1988), Santiam Highway (Oregon -October 1988), and Maine (October 1987). The Natchez Trace (NT) and Santiam Highway (SH) data have been published;(",") however, the information collected from several sites in Maine is previously unpublished. 1. ALABAM.4 AND ORE:GON SITES, (a) Results. The data are listed in Table 4, by type of pipe and location. Figure 6 shows the performance of the bituminous -coated galvanized pipes sampled in this study. The dashed lines in the figure represent an estimated corrosion path. For the Santiam Highway (SH) point, the corrosion path essentially coincides with the line of equality. These pipes should have experienced no metal loss (zero percent actual perforation) as long as the bituminous coating remained intact, even though a metal loss is predicted by the California method. Then, actual metal loss could be assumed to proceed along a line parallel to the line of equality. This behavior is portrayed by a corrosion path up the vertical axis and along the dashed line from the vertical axis to each data point. The fraction of the estimated metal loss for which there was no actual metal loss, to the total estimated metal loss, is proportional to the fraction of the pipe's age (here 7 years) for which the bituminous coating provided corrosion protection. Scaling this proportion using the constructions shown in Figure 6, the life of the bituminous coating is estimated at only 0-5 years of the pipe's 7-year age. Figure 7 shows the performance of the aluminum -coated type 2 pipe sampled. The average performance is indicated by the solid line, which begins at the origin and passes through the centroid of the data. The slope of this line represents the relative performance of these pipes compared to the average performance of plain galvanized pipes, according to the California 29 Table 4, Natchez Trace (NT) and Santiam Highway (SH) Sites('e,51) Water Soil Thickness Location pH Resistivity (ohm -cm) pH Minimum Resistivity (ohin-cm) Original Seven Year Percent Perforation Bituminous -Coated Galvanized Pipe NT 310.6 7.4 3.000 5.5 5,500 0.057 0.050 12.3 SH 113+25 6.7 16,800 5.4 5,500 0.059 0.048 18.6 SH 119+20 6.5 17,100 6.25 8,700 0.059 0.056 5.1 Aluminum -coated Type 2 Pipe N'r 310.6 7.4 3,000 5.5 5,500 F 0.058 0.056 3.5 N'r 311.9 7.1 2,000 7.5 3,100 0.058 0.056 3.5 NT 312.4 7.6 9,000 7.3 4,000 0.058 0,058 0.0 NT 312,4 7.6 9,000 7.3 4,000 0.058 0.057 1.7 SH 13+-00 6.8 35,700 5.3 10,800 0.058 0.058 0.0 SH 18+20 6.4 46.500 4.2 9,400 0.058 0,058 0.0 SH W38+12 6.85 13,700 5.3 3,800 0.074 0.072 2.7 SH E38+12 6.85 13,700 5.3 3,800 0.074 0.072 2.7 SH 44+50 7.3 20,900 5.7 5,200 0.058 0.055 5.2 SH E90+38 6.7 15,500 5.5 2,600 0,057 0.056 1.8 SH 100+15 6.5 17,400 4.7 6,200. 0,059 0.058 1.7 SHIJ 104+45 6.8 20,000 5.7 6,600 0.128 0.125 2.3 SHE 104+45 6.0 20,700 5.7 6,600 0.128 0.118 7.8 SH 123+76 6.3 15,400 5.5 4,900 0.057 0.057 0.0 NT 310.0' 7.6 9,000 2.5 290 0.058 0.000 100.0 NT 310.1.b 8.6 29,000 2.5 290 0,058 0.009 84.5 Aluminum -zinc Coated Pipe NT 311.9 7.1 2,000 7.5 1 3,100 0.056 0,049 12.5 Aluminum Pipe NT 312.4 7-6 9,000 7.3 4,000 0.074 0.074 0.00 'Fe bFe = 6,575 = 6,380 mg/kg; mg/kg; Cu = 9.05 Cu = 8.85 mg/kg; mg/kg; and and SO4 = 880 mg/kg. SO, - 965 mg/kg. 30 25 q < 20 0 15 a MZ 10 0 v_ L> U 5 / / —•5 1 RS / 4 / LEGEND / / O SANTIAM HWY +,./--•I YR ❑ NATCHEZ TRACE ,� • 0 YRS 0 C 5 10 15 20 25 Z ACTUAL PERFORATION Figure G. Bituminous-coated•Gelvonized CSP performance (48.51) 25 A0 a 20 0 15 a \ 5 o �— Q OUTLIERS 0 MILE 310) N b l� ❑ / /y / O / Q / / / I LEGEND O SANTIAM HWY ❑ NATCHEZ TRACE / 0 0 5 10 15 20 25 Y. ACTUAL PERFORATION Figure 7. Aluminum -coated Type 2 CSP performance (a5, 51) 31 method. The average corrosion rate for the 14 pipes included in this data set is 6.2 times slower than estimated by the California method. This is consistent with the range of two -to -six determined from the manufacturer's data. Some variability in predicted corrosion rates, due to differences in abrasion or aspects of soil and water chemistry not used with the California method, is normal. But this much lower corrosion rate appears to exceed that expected variability, suggesting a corrosion mechanism significantly different from that of.galvanized CSP. As a relatively noncorrosive metal, aluminum can be expected to act as a protective barrier to corrosion of the steel. substrate. Durability experiencewith aluminum structural plate pipe suggests that this protection may be substantial, Aluminum is also slightly anodic to steel, thus providing modest, sacrificial cathodic protection. This explains and is confirmed by the observed absence of excessive or preferential corrosion at the cut edges and welded seams of aluminum coated pipe. This is similar to the protective mechanism which makes aluminum CSP more durable than aluminum structural plate,"" Aluminum CSP consists of an aluminum substrate (alloy 3004) covered with a slightly different aluminum cladding (alloy 7072). The cladding provides sacrificial protection to the thicker substrate.'14) On steel, an aluminum coating likely acts as a balanced barrier and sacrificial anode to produce a significantly lower corrosion rate than for galvanized CSP. Two aluminum -coated pipes (NT 310.0 and NT 310.1) were omitted from this data set. Unusual corrosion in these pipes and their concrete headwalls suggested a periodically aggressive effluent far more severe than would be suggested by the measured water chemistry, further investigation revealed a very corrosive soil deposit in the drainage feature that was subject to leaching by ground water and surface runoff only during wetter conditions than those prevailing at the time of this study. The soil contains heavy metals and has a pH of 2.5 and a resistivity of 290 ohm -cm. Heavy-metal concentrations from samples at these locations are included in Table 4. Water draining these soils would fall well outside of the environmental ranges recommended for any type metal pipe. Their performance should thus not be directly compared with the other test sites, or with predictions based on the California method. 32 These test installations included only one pipe each of aluminum [AASHTO M196 ("Standard" 1989a)] and aluminum -zinc coated JAASHTO M36 ("Standard" 1989)) pipe. Therefore, only the broadest generalizations can be made about their relative performance. The aluminum pipe sample showed no metal loss, suggesting that its service life at mile 312.4 is indefinite. The aluminum -zinc coated (Galvalume) pipe sample showed more metal loss than the aluminum coated pipe at that location, but less than that predicted by the California method, suggesting that aluminum -zinc coated performance lies between galvanized performance and aluminum coated performance. All four types of pipe were included in three dual installations in Alabama. The side -by -side performance of these pipes is shown in Figure 8. The dashed lines between data points indicate the pipes that were paired in each installation. This comparison shows the relative performance of each material in like environments, consistent with the previous observations. It also demonstrates that the California method is a reasonable estimator of the relative aggressiveness of each site. (b) Conclusions." ") The conclusions of this study are limited by the small size of the data set and the young age of the data. However, there is sufficient data to suggest several significant observations. Theanalytical procedure followed in this study provides a rational, quantitative, and objective measure of comparative performance. Bituminous coatings provide very little additional life for galvanized pipe, and are probably not cost-effective. During the first 7 years of exposure, aluminum -coated type 2 pipe performed an average of over sir times better than the California method predicts for plain galvanized at the fourteen sites investigated, Future studies should be conducted to follow this performance trend to perforation or beyond. 2. MAINE SITES. Eleven different sites were visited in Maine. These sites contained CSP pipe with zinc, aluminum -zinc, or aluminum -coated type 2 protective coatings. A summary of these sites and observed conditions of the various pipes are given on Table 5. Direct comparisons of performance can be made of the zinc coated and aluminum -zinc coated pipes at the Brewer and Newburgh sites. The 33 25 0 20 d 15 0 0 0 L 0 / rJ", /oo / / LEGEND / O ALUMINUM -COATED TYPE 2 O BIT. COATED GALV. 6 ALUMINUM -ZINC COATED 0 ALUMINUM r 5 10 15 20 25 Z ACTUAL PERFORATION Figure 11. Side -by -side performance compnrisions(48,51) 3� J P m H L N - v w u G a! u o a a a J u m h G O o p vi U v v G v m v n u - m G .. G. 7 ro� m :L � u •o h w a u u v a u u E E u u> 'O �T 60 0 v m C -p G E O V m u G - '+ 3 G v C a 3 u m N •+ +-+-+ S E O v Ow E E C W v o 0 J 'O O •p u G o u •.i 1, v m m .ti G w O > >, C 0 0 o ,-. u C v C T S •+ 0 C J 'O 00 J C ✓+ 'N N� 3 O b0� v U EE ti 7 v m O U m m u L m u> r+ m u "p d OV u v t v eo m ro m v 3 G uU1 m> C G> v u L G •.+ O O u P ., C .+ u G v G O m E m w m .+ .-+ m W u 3 .ti o v v 7 v O J N O cD > 3 N -0 U t0 'O 'O W V 00 G w ..C: o O C V-+ L 7 m v -+ E P 3 v Y. v G m + v m •-+ a .ti m J 'D •N N pp 10 010 n m P -+ G •'1 h P O m y -+ 0. X m L O U 1J N N •.� L L l+ 1� 3 O � L C E a u 3 o r+ o y o o a m o o0 u N v m G N 3 0 u u C. C :I 7 O m v 00 c O eD 'O u u� 3 + P �] m V •.+ 'O -� u u1 C -+ oD v G G u •O E u m T p u m y m 0 0 0 .+ v J D v 0 m m O �C u E v .-+ u a G U E u }. h E v o u v •.+ 0 O a 1n u1 U P N C .ti V v N v- u N v C: C O v L v .+ •.a v u u .y C m C •� 0 0 U N m -+ a U .+ •.+ 0 0 0 O O N 0 3 q M q u O U U L v L 3 2 N U N U N U v ❑ G H T T T E u E E u EE E, u 7 J 7 7 7 u E u U E E u E u E u E V m J m G 7 7 m 7 G J m J G O Q V N Q Q V Q N Q U Q N 9 V VI N I-- •-i r-1 r-+ rti rti ti '-1 rJ G m O � Y m O v v m 7 G r• u v L 3 v v u � E 3 O O ..I U C = u U C N N E C ro o L E E C N ro .y E O s C E u o r+ E u C E cJ' O o v ro C a> o u m � 2 O U U - O O m E A r v C 3 .� U o C 'C •-! 3 C O ro N N O ..J C-+ ••! V O O •+ '+ 3 'p E G u u m u N J O P ✓t U) ✓� u .t GO U i1 ro C Ol rn ro a. o bo ... u E G N u + C L 3 G u l7 u L A 3 o u p •.+ G G ro u .. . . N o N T E u 3 w N 'O N u u 3 y ' N E L C G 'L U ro 3 v N O N .0 u u C C •-+ !0 W E a: E ro ro y O N N u C. G W C 'O N C - v W O .+ C O •.+ G O LL o v i ro es a s v •.+ 1 C of E •O •-� o o v m m a u O N a, v U U N •ti N ro u V N 0 N N N a 4J O v u L U u �: ro o v oO ro m F u u v v u ro u u u u A 3 ro 0 0 O N O -+ a •+ •+ u D U C) a C4 u Cy U U o C u E u u o h m V v o a c u O u N L O ro N u C U C C A a O ••+ [ N U V U u ro v [ U .C U ..! U UI N N O ro E C w vl T C L \ E N E ro [ u 7 u t A N .ti E u O 3 v v o a u c a o w E o ro G u v L E v v ro v es u J •O op C a 3 0) + v ro -! v •-+ W E u 3 ti ro 0 o0 G N a .m a W L U :- C ro o O O v u o u ro a v a4 r. o N U O U O L! C u W U u •.+ u L ro u v o v U O. N u CL ••� T M W E O) N N N Ul vi T ro u! ro9+a mz� o O 0 u 0 u E J u N nJ N •-+ C. u u C O y OO- G W E .•� v 3 '•� 7 U O. CL C •n m m m V U N C a V N N O. E E E u 7 J O C C G 9 E E u E u 7 J C J ro 6 Q N Q V n n n n rn rn a rn L t0 u J A 3 0 z m m a D` .a .N R. observed conditions of the pipe (Table 5) revealed that the aluminum -zinc coated pipes were performing better than the zinc -coated pipes. Direct comparisons of performance can be made of the aluminum - zinc, aluminum -coated type 2 and zinc coated pipes at the Carland, Milford, and Arrington sites. The observed condition of the pipe (Table 5) revealed that the aluminum -coated type 2 pipe was performing better than the other two coated pipes. The aluminum -zinc coated was also performing better than the zinc -coated. A study by the Maine Department of Transportationl2l on some of these same sites also revealed that the aluminum -coated type 2 pipe was performing well with most pipe being near the original condition. 37 V. PROTECTIVE COATINGS FOR CORRUGATED STEEL PIPE Protective coatings (nonmetallic and alternate metallic) have been and are being used on CSP to extend the service life of the pipe. A number of these coatings are listed in the following paragraphs. Based on the literature review of various field applications and limited field site visits completed in this study, an add -on service life expected for each coating mentioned is given. A. NONMETALLIC COATINGS 1. BITUMINOUS COATING. (See AASHTO M190111), ASTM A 8491"71. ) A bituminous coating may add 8 to 10 years)4,13,50.76) of service life to zinc coated CSP where waterside corrosion is the dominant influence. However, a number of states(22,28."1,71,73,60) have discontinued the use of bituminous coating since the add -on service life of the coating has proved to be uneconomical for preventing waterside corrosion. The American Iron and Steel Institute (AISI) Handbook of Steel Drainage and Highway Construction Products"'J mentions that bituminous coating for exterior corrosion protection provides significant added life. The AISI Handbook also mentions that California estimates that 25 years added life is provided by bituminous coating when soilside corrosion is the critical factor. others (9,22.50.70) have also arrived at this conclusion. 2. BITUMINOUS COATED AND PAVED. (See AASHTO M190)11), ASTH A 849)47).) Bituminous coating and paving may provide 25 to 30 years(13,22,24.26,41,43,50,56,57) add -on life to zinc coated CSP. 3. ARAMID FIBER BONDED COATING. (See ASTM A 88517".) This coating is intended as the replacement product for the historically durable asbestos bonded coating. This study revealed little documented field experience with the aramid. The State of Louisiana)4') has conducted comparative laboratory testing of aramid fiber bonded corrugated zinc coated steel and asbestos bonded corrugated zinc coated steel. From these tests, they concluded the aramid fiber bonded pipe will not perform as well as the asbestos bonded pipe. However, they are conducting a field performance evaluation of the two types of coating. Before an add -on life (in years) with the use of an aramid fiber bonded coating on CSP can be given, more field experience data is required to document a specific number of years. 38 4. CONCRETE LINED. (See ASTM A 8491471.) Characteristic cracks in concrete would allow water penetration to the zinc coated CSP, offsetting the protective benefit of the concrete lining. In June 1960, concrete lining was installed in several asphalt coated galvanized CSP. These pipes were inspected in June 19861491 and were found to be in good condition with one exhibiting evidence of bedload abrasion. The condition of these pipes is not known at this time, however, concrete lining over asphalt coated galvanized CSP should provide an add -on life of 26 years or more. 5. POLYMER COATING. (See AASHTO M245(19), M246165), ASTM A 742(69), ASTM A 762120).) Review of published reports and installation site visits provided information on the service life of coal tar base resin, poly -vinyl chloride (PVC) plastisol and ethylene acrylic acid film polymer coatings when used with CSP. The first two coatings are not currently available although there are installations which contain these coatings on CSP. The expected add -on life of galvanized CSP when coated with either of the three polymer coatings are presented below, (a) Coal Tar Base Resin (Nexon). This coating should provide an add - on life of 6 to 8 years(27,32.41,52,75,76) to galvanized CSP if not damaged by abrasion. (30, 56, n) Abrasive damage typically occurs in the first two years in an abrasive environment.(41.52,53,55) (b) Poly -vinyl Chloride (PVC) Plastisol (Beth-Cu-Lov). This coating should provide an add -on life of 8 to 10 years (52.53,54,75) to galvanized CSP if not damaged by abrasion. (30,58.71) As with the coal tar base resin, abrasive damage typically occurs in the first 2 years in an abrasive environment. (11,52,53,55) (c) Ethylene Acrylic Acid Film (DAF 625). Results of site visits (see Table 1) reveal that this type coating (10 mil inside and outside thickness) has performed well and was still in excellent condition (although it had been subjected to some bedload) after more than 14 years of in-service use. At one site, the outside coating (thickness, 3 mil) had delaminated at an exposed pipe end but no rusting of the pipe had occurred. Published"'.31.50,75.76) information on the durability of this type coating also revealed that it hasperformedsatisfactory for years. Based on this study (site visits and published information), this coating with a 10 mil thickness (inside and outside) should provide an add -on life of 28 to 30 years 39 j; !" to galvanized CSP if not damaged by abrasion. e11,5e,1i) Abrasive damage, as mentioned above, typically occurs in the first 2 years in an abrasive environment. 6. EPDXY COATING. Epoxy coating is applied to the base metal of CSP without galvanizing. Therefore, this type of coated pipe system is not likely to last as long as a pipe system such as the polymer coated galvanized CSP. Published information( 53. 75, 76) relative to epoxy coated pipe cover periods of I' installation use up to about 5 years. During the limited site visits, only two sites were observed to contain epoxy coated pipe (New York - see Table 2 and Vermont - see Table 3). The bedload was heavy at these sites with the �e coating being damaged with resulting rusty metal after a period of 5 to 8 i years. Before an add -on life with the use of epoxy coating on CSP can be given, additional field experience data is required. B. METALLIC COATINGS Two metallic (in addition to galvanized) coatings have been used with CSP to extend the service life. These are aluminum -zinc (Galvalume-see AASHTO M289"), ASTM A 792(65) and A 8W "� ) and aluminum -coated type 2 (see AASHTO M27063), ASTM A 463(67), and A 8191641) coatings. 1. ALUMINUM -ZINC COATING. An aluminum -zinc coaling on CSP should provide '^ "',") i about the same expected life as that provided by a zinc coating (galvanized). 2. ALU14INUM-COATED TYPE 2. Within the recommended application guidelines aluminum -coated type 2 CSP should provide an expected service life of twice that of galvanized CSP.(44,4B,50,5i' But, as with galvanized pipe, there are ` design limits within which the predicted performance is valid. These limits are dependent upon the corrosivity of the operational environment as characterized by both soil and waterside chemistry. These limits for aluminum -coated type 2 are as follows: Soil and Water off Minimum Soil Resistivity Ohm Cm 5-9 > 1,500 These guidelines would preclude its use as sanitary and industrial sewers where there is likelihood of effluent pH's below the design minimum. Investigations performed by the authors at an aluminum -coated type 2 CSP site in Monroe, Louisiana support these limits. Numerous perforations near and above the flow line were found occurring in the valleys of the corrugations 40 originating from the soilside. The observed soil chemistry consisted of pH's as low as 3.4 and resistivities approaching 1500 ehms.cm. Also at another aluminum -coated type 2 location in Augusta, Georgia, the CSP required replacement after 12 years of service because of periodic industrial or sanitary discharge. AlLuninum-coated type 2 material also should not be used uncoated when subjected to acid mine runoff, saline water, or effluent and soils containing soluble heavy metals. 41 I 1 a� VI. DURABILITY ESTIMATION (EXPECTED SERVICE LIFE) FOR GALVANIZED CORRUGATED STEEL PIPE In order to determine the expected service life of galvanized CSP for a particular application, specific information is required in three areas. The areas included in the specific information are: waterside chemistry, bedload, and soilside chemistry. A. PROCEDURE 1. CHECK WATERSIDE CHEMISTRY. Assume the proposed site for galvanized CSP usage will have water turbulence to provide sufficient dissolved oxygen to support corrosion or scaling. Temperature effects are assumed not to be significant in environments sufficiently mild to allow a service life of at least 50 years. For areas with no dry weather flow, use chemistry of surface water runoff. Any dry weather flow chemistry is critical due to extended con -.act time. Use the procedure (Scaling Tendency and Modified California Chart) presented in Section III to determine the service life of the base line galvanized CSP. If the indicated service life of the galvanized CSP deter- mined from this procedure is not 50 years or more, consideration can then be given to adding one of the protective coatings described in Section V. 2. CHECK ABRASION/BEDLOAD POTENTIAL. Installations with extraordinarily abrasive conditions may experience a shorter life.f5" Abrasion is a function of velocity and bedload. In the absence of bedload, abrasion will not be a factor. Abrasive materials will not be transported by flows of less than about 5 ft/sec. Therefore, abrasion is not a factor at low velocities without regard to bedload. Abrasion is a factor when abrasive bedloads are present and flow velocities are high enough to transport them. (a) None/sand/silt/clay/small pebbles. Any of the coatings and their corresponding add -on lines given in Section V should be used as necessary to provide a service life of 50 years or more (where chemistry determination indicate the galvanized CSP alone will not perform for at least 50 years). (b) Gravel/cobbles. Consider using only metallic, smooth flow coatings (paving or lining) or metal liner places. (c) Boulders. None of the currently available coatings are satis- factory for 50 years of service life. 42 3. CHECK SOILSIDE CHEMISTRY. Soilside chemistry determination is generally necessary only in the arid southwest (see Section III and references 43, 64, 61, and 79), However, to determine the expected life on the soilside, the soilside pH and resistivity is used (formula or chart given on Figure 2) to calculate pipe life, The pipe life determined is for an 18-gage thick pipe. Therefore, when the pipe under consideration has a metal thickness other than 18-gage, the 18-gage pipe life is multiplied by the factor for that gage (i.e. 16-gage factor is 1.3; see Figure 2) to determine the 16-gage pipe life. If this life determined is not at least 50 years, any nonmetallic coating (which will be held in place by soil backfill) applied over the galvanized CSP should bring the service life up to or over 50 years. B, EXAMPLE A site requires a CSP with a 50-year design life to be installed. This site is in a temperate climate zone, negligible bedload with soilside conditions; pH of 6.0, minimum resistivity (R) of 17,000 ohms -cm; waterside conditions, dry weather flow, pH of 6.0, conductivity (C) of 600 µmhos/cm, hardness as CaCO3 of 950 p.p.m. and alkalinity as CaCO3 of 100 p.p.m. Check to see if a 16-gage galvanized CSP will satisfy the requirements for this application. 1. WATERSIDE. From Section III, Scaling Tendency"'" = Hardness + Alkalinity - Free COz Where: Hardness as Ca'z Alkalinity as HCO3- Free CO2 = alkalinity ancilog(pH-6.22) Hardness as Ca*z = 0.4 x hardness as CaCO3 = 0.4 x 950 - 380 p.p.m. Alkalinity as HCO3- = 1.22 x alkalinity as CaCO3 = 1.22 x 100 - 122 p.p.m. Free CO2 - 122 - 202 p.p.m. ancilog(6.0-6.22) = 200' from Figure 9(10,ec) Therefore: Scaling Tendency = 380 + 122 - 202 = 300 Then from Figure 4 at Scaling Tendency of = 300 and conductivity of 600 µmhos/cm read = 40 years life for 14-gage pipe. To convert from 14-gage to 16-gage pipe, use gage factors given on Figure 2 (California Chart). 43 1 0 0 00 0 0 0 0 000 0 0 0 000 0 o n Nan ni Wdd "0D 33d.a M 44 o 1 Na n " _T C w n From Figure 2 gage factor for 14-gage is 1.6 (chart based on 18-gage pipe) Therefore: 40/1.6 = 25 years for 18-gage galvanized CSP life. To convert from 18-gage to 16-gage pipe life, multiply expected life of 18-gage by a factor of 1.3 (from Figure 2). 1.3 x 25 = 32 years which falls short of 50 year desired design life. 2. BEDLOAD. Since the bedload is negligible, any coating added to the above galvanized CSP to provide a expected service life of at least 50 years would be acceptable. :. use an ethylene acrylic acid film (polymer) coating with an expected add -on life to galvanized CSP of 30 years. Total expected service life = life of galvanized CSP + coating add -on life 32 + 30 = 62 years expected service life based on waterside condition 3. SOILSIDE. From figure 2 at minimum resistivity (R) of 17,000 ohm -cm and pH of 6.0, years to perforation of 18-gage pipe is approximately 26. To calculate life, use the formula from Figure 2. Years = 13.79 [Log1OR - Loglp(2160-2490 Log10pH))"'I = 13.79 [Log,, 17,000 - Loglo(2160 - 2490 Loglo 6.0)] — 25.9 = 26 years Then using a gage factor of 1.3 to convert years to first perforation of 18-gage to 16-gage: 1.3 x 26 = 34 years for 16-gage to first perforation which falls short of 50-year desired design life. Therefore, use add -on expected life of ethylene acrylic acid film (polymer) coating of 30 years to give: Total expected service life = 34 + 30 — 64 years based on soil side conditions. 45 VII. CONCLUSIONS AND RECOMMENDATIONS A. CONCLUSIONS The following conclusions are based on a literature review of work conducted by others and limited field site observations. The procedure presented in Section III and used in the example in Section VI takes into account the waterside scaling potential of metal pipe installations and provides a more accurate method than the California Method of the prediction of CSP service life. For galvanized CSP installations where this type pipe alone is not expected to attain a desired design life of 50 years, applicable protective coatings (nonmetallic and metallic) may be added to extend the service life to at least 50 years. B. RECOIMIENDATIONS. For any installation where more than one type coating for CSP will satisfy the requirements to provide an expected service life of at least 50 years, use the one with the lowest first cost. Monitor installation sites to collect additional information relative to performance of corrugated steel pipe with various coatings. 46 REFERENCES 1. American Iron and Steel Institute. 1983. "Handbook of Steel Drainage and Highway Construction Products," 3rd Edition, Washington, DC. 2. Alley, M. D. 1984 (November). "Culvert Study," Interim Report, Technical Services Division, Department of Transportation, State of Maine. 3. "Aluminum -Zinc Alloy Coated Steel Sheet for Corrugated Steel Pipe," 1986. 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"Evaluation of the Durability of Metal Drainage Pipe," Transportation Research Record 762, pages 25-32, Transportation Research Board, Washington, DC. 33. Larson, T. E. and Skold, R. V. 1958 (June). "Laboratory Studies Relating Mineral Quality of Water to Corrosion of Steel and Cast Iron," Corrosion 34. Langelier, W. F. 1946. "Chemical F-quilibria in Water Treatment," Volume 38, pages 169-178, American Water Works Association, Baltimore, MD. 35. Langelier, W. F. 1946. "Effect of Temperature on the pH of Natural Waters," Volume 38, pages 179-185, American Water Works Association, Baltimore. MD. 36. Langelier, W. F. 1936. "The Analytical Control of Anti -Corrosion (dater Treatment," Volume 28, American Water Works Association, Baltimore, MD. 37. Lindberg, R. I. 1967. "Method of Estimating Corrosion of Highway Culverts by Means of Polarization Curves," Highway Research Record 204, page 1, Highway Research Board, Washington, DC. 38, Lowe, T. A., Vaterlaus, R. H., Lindberg, R, I. and Lawrencs, L. R. 1969. "Corrosion Evaluation of Aluminum Culvert Based on Field Performance," Highway Research Record 262, Highway Research Board, Washington, DC. 39, McCauley, R. F. and Abdullah, M. 0. 1958. "Carbonate for Pipe Protection," Volume 50, page 1419, American Water Works Association, Baltimore, MD. 40. McKee, A. B. and Brown, R. H. 1947 (December). "Resistance of Aluminum to Corrosion in Solutions Containing Various Anions and Cations," Corrosion, Volume 3, No. 12, pages 595-612, National Association of Corrosion Engineers, Houston. TX. 41. Meacham, D. C., Hurd, J. 0. and Shisler, Culvert Durability Study," Report ODOT/L&D/82 Transportation, Columbus, OH. 49 W, W, 1982 (January). "Ohio 1, Ohio Department of 42. "Method for Estimating the Service Life of Steel Culverts," 1978. California Test 643, Department of Transportation, Division of Construction, Sacramento, CA. 43. "Modern Sewer Design," 1990. American Iron and Steel Institute, ` Washington, DC. ti 44. Morris, G. E. and Bednar, L. 1984. "Comprehensive Evaluation of Aluminized Steel Type 2 Pipe Field Performance," Transportation Research Record 1001, pages 49-59, Transportation Research Board, Washington, DC. 45. Nordlin, E. F. and Stratfull, R. F. 1965. "A Preliminary Study of FAluminum as a Culvert Material," Highway Research Record 95, page 1, Highway Research Board, Washington, DC. Vi 46. Poche, J. J. and Clement, K. A. 1989 (August). "Comparative Laboratory Testing of Aramid Fiber Bonded Corrugated Galvanized Steel and Asbestos Bonded Corrugated Galvanized Steel," Louisiana Department of Transportation, Baton Rouge, LA. 47. "Post -Coated and Lined Corrugated Steel Sewer and Drainage Pipe (Bituminous or Concrete)," 1989, ASTM A 849-89, American Society for Testing and Materials, Philadelphia, PA. 48. Potter, J. C. 1990 (March/April). "Aluminum Coated Corrugated Steel Pipe Field Performance," Journal of Transportation Engineering, American Society of Civil Engineers, Volume 116, Number 2, pages 145-152, New York, NY. 49. Potter, J. C. 1986 (November). "Evaluation of Buried Concrete -Lined Corrugated Metal Pipe," Miscellaneous Paper CL 86-33, US Army Engineer Waterways Experiment Station, Vicksburg, MS. 50. Potter, J. C. 1988 (February). "Life Cycle Cost for Drainage Structures," Technical Report GL 88-2,'US Army Engineer Waterways Experiment Station, Vicksburg, MS. 51. Potter, J. C. 1988 (November). "Quantitative Analysis of FHWA Aluminized Type 2 CSP Field Test Installations," Memorandum For Federal Highway Administration, HDF-12, Washington, DC, 52. Pyskadlo, R. M. 1989 (May). "Performance of Polymer -Coated and Bituminous -Coated -and - Paved Corrugated Steel Pipe," Report FHWA/NY/SR-89-94, New York State Department of Transportation for Federal Highway Administration, Washington, DC. 53, Pyskadlo, R. M. and Ewing, J. P. 1987 (September). "Coatings for Corrugated Steel Pipe," Report FHWA/NY/SR-87/90, New York State Department of Transportation for Federal Highway Administration, Washington, DC. 50 f.: 54, Pyskadlo, R. M, and Renfrew, W. W. 1984 (July). "An Overview of Polymer Coatings for Corrugated Steel Pipe in New York," Report FHWA/NY/SR-84/79, New York State Department of Transportation for Federal Highway Administration, Washington, DC. 55. Pyskadlo, R. M. and Renfrew, W. W. 1984. "Overview of Polymer Coatings for Corrugated Steel Pipe in New York," Transportation Research Record 1001, pages 21-26, Transportation Research Board, Washington, DC. 56. Renfrew, W. W. 1984, "Durability of Asphalt Coating and Paving on Corrugated Steel Culverts in New York," Transportation Research Record 1001, pages 26-34, Transportation Research Board, Washington, DC. 57.. Renfrew, W. W. 1984 (July). "Durability of Asphalt Coating and Paving on Corrugated Steel Culverts in New York," Report FHWA/NY/SR-84/80, New York State Department of Transportation for Federal Highway Administration, Washington, DC. 58. Ring, G. W. 1984. "Culvert Durability: Where Are We?" Transportation Research Record 1001, pages 1-9, Transportation Research Board, Washington, DC. 59. Schwerdtfeger, W. J. 1966. "Soil Resistivity as Related to Underground Corrosion and Cathodic Protection," Highway Research Record 110, page 20, Highway Research Board, Washington, DC, 60. Serf, D. F. and Bednar, L. 1989 (October). "Durability of Plain Galvanized Steel Drainage Pipe in South America" Criteria for Selection of Plain Galvanized," Armco, Inc., Middletown, OH. 61. Shrier, L. L. 1977. "Corrosion," Volume 1, Butterworth (Publishers) Inc. Woburn, MA, 62. Stavros, A. J. 1984. "Aluminum -zinc Corrugated Steel Pipe: A Performance Study," Transportation Research Record 1001, pages 69-76, Transportation Research Board, Washington, DC. 63. "Steel Sheet, Aluminum -Coated (Type 2) for Corrugated Steel Pipe," 1984. AASHTO M274-84, The American Association of State Highway and Transportation Officials, Washington, DC. 64. "Steel Sheet, Aluminum -Coated Type 2 for Storm Sewer and Drainage Pipe," 1984, ASTM A 819-84, American Society for Testing and Materials, Philadelphia, PA. 65. "Steel Sheet, Aluminum -Zinc Alloy Coated by the Hot -Dip Process, General Requirements," 1989. ASTM A 792-89, American Society for Testing and Materials, Philadelphia, PA. 66. "Steel Sheet, Aluminum -Zinc Alloy Coated by the Hot -Dip Process for Storm Sewer and Drainage Pipe," 1988. ASTM A 806-88, American Society for Testing and Materials, Philadelphia, PA. 51 67. "Steel Sheet, Cold -Rolled, Aluminum -Coated Type 1 and Type 2 , " 1988. ASTM A 463-88. American Society for Testing and Materials, Philadelphia, PA. 68, "Steel Sheet, Metallic -Coated and Polymer Precoated for Corrugated Steel Pipe," 1986. AASHTO M246-86, The American Association of State Highway and Transportation Officials, Washington, DC. 69, "Steel Sheet, Metallic -Coated and Polymer Precoated for Corrugated Steel Pipe," 1986, ASTM A 742-86. American Society for Testing and Materials, Philadelphia, PA. 70. "Steel Sheet, Zinc and Aramid Fiber Composite Coated for Corrugated Steel Sewer Culvert and Underdrain Pipe," 1988. Astm A 885-88, American Society for Testing and Materials, Philadelphia, PA. 71. "Study of Use, Durability, and Cost of Corrugated Steel Pipe on the Missouri Highway and Transportation Department's Highway System," 1984 (May). Study Number MR 87-1, Missouri Highway and Transportation Department, Jefferson City, MO. 72. Stum, W. 1960. "Investigations of Corrosive Behavior of Waters," Proceedings of the American Society of Civil Engineers, Sanitary Engineering Division, Volume 86, No. SA6, Ann Arbor, MI. 73. Sudol, J. J. 1982 (September). "Pipe Coating Study," Indiana Department of Highways. West Lafayette, IN. 74. Summerson, T. J. 1984, "Corrosion Resistance of Aluminum Drainage Products: The First 25 Years," Transportation Research Record 1001, Transportation Research Board, Washington, DC. 75. Temple, W. H. and Cumbaa, S. L. 1986. "Evaluation of Metal Drainage Pipe Durability After Ten Years," Transportation Research Record 1087, pages 7-14, Transportation Research Board, Washington, DC. 76. Temple, W. H., Cumbaa, S. L., and Cueho, B. J. 1985 (March). "Evaluation of Drainage Pipe by Field Experimentation and Supplementary Laboratory Experimentation," Report FHWA/LA-85/174, Louisiana Department of Transportation and Development for Federal Highway Administration, Washington, DC. 77. Tillmans, J. 1932. "Die Chemische Untersuchung Von Wasser and Abrvasser," 2nd Edition, Wilhelm Knapp Halle (Saale). 78, Tupac, C. J. 1984. "Corrosion Survey on Corrugated Steel Culvert Pipe," to State of California Department of Transportation for USS-Posco, USX, Pittsburgh, PA. 79. Welch, B. H. 1976. "Pipe Corrosion and Protective Coatings," Transportation Research Record 604, pages 20-24, Transportation Research Board, Washington, DC. 52 80, 6brley, H. E. and Crumpton, C. F. 1972. "Corrosion and Service Life of Corrugated Metal Pipe in Kansas," Highway Research Record 412, pages 35-40, Highway Research Board, Washington, DC. 53 APPENDIX A: BIBLIOGRAPHY American Iron and Steel Institute. 1983. "Handbook of Steel Drainage and Highway Construction Products," 3rd Edition, Washington, DC. Alley, M.D. 1987 (November). "Culvert Study," Interim Report, Technical Services Division, Department of Transportation, State of Maine. "Aluminum -Zinc Alloy Coated Steel Sheet for Corrugated Steel Pipe," 1986, AASHTO M289-86, The American Association of State Highway and Transportation Officials, Washington, DC. Azar, D. G. 1971 (May). "Drainage Pipe Study," Louisiana Department of Highways, Baton Rouge, LA. Baylis, J. R. 1935. "Treatment of Water to Prevent Corrosion," Volume 27, pages 220-234, American Water Works Association, Baltimore, MD. Beaton, J. L. and Stratfull, R. F. 1962. "Field Test for Estimating Service Life of Corrugated Metal Pipe Culverts," Highway Research Board Proceedings, 41st Annual Meeting, Washington, DC. Bednar, L. 19B9. "Durability of Plain Galvanized Steel Drainage Pipe in South America: Criteria for Selection," Transportation Research Record 1231, pages 80-87, Transportation Research Board, Washington, DC. Bednar, L. 1989. "Plain Galvanized Steel Drainage Pipe Durability Estimation with a Modified California Chart," Transportation Research Record 1231, pages 70-79, Transportation Research Board, Washington, DC. Bel lair, P. J. and Ewing, J. P. 1984. "Metal Loss of Uncoated Steel and Aluminum Culverts in New York," Transportation Research Record 1001, pages 60-66, Transportation Research Board, Washington, DC. Berg, V. W. 1965 (April). "A Culvert Material Performance Evaluation in the State of Washington," Washington State Highway Commission, Olympia, WA. Betz Handbook of Industrial Water Conditioning, 1980. Betz Laboratories, Inc., Trevose, PA. - "Bituminous Coated Corrugated Metal Culvert Pipe and Pipe Arches," 1986. A.ASHTO M190-86, The American Association of State Highway and Transportation Officials, Washington, DC. Brown, R. P. and Kessler, R. J. 1976. "Fundamentals of Corrosion," Transportation Research Record 604, page 16, Transportation Research Board, Washington, DC. Brown, R. P. and Kessler, R. J. 1975 (November). "Performance Evaluation of Corrugated Metal Culverts in Florida," Florida Department of Transportation, Gainesville. FL. Al Bulter, B. E. 1972. "Structural Design Practice of Pipe Culverts," Highway Research Record 413, Transportation Research Board, Washington, DC. Bulter, G. and Ison, H. C. K. 1966. "Corrosion and Its Prevention in Waters," pages 16, 29, and 32, Reinhold Publishing Corporation, New fork, NY. Camp, T. R. 1963. "Water and Its Impurities," Reinhold Publishing Corporation, New York, NY. "Condition and Corrosion Survey, Soil Side Durability of Corrugated Steel Pipe," 1990 (November). Prepared by Corrpro Companies, Inc. for the National Corrugated Steel Pipe Association, Washington, DC. "Corrosion Control by Deposition of CaCO3 Films," 1978. A Handbook of Practical Application and Instruction, American Water Works Association, Baltimore, MD. "Corrugated Steel Pipe, Metallic -Coated for Sewers and Drains," 1986. AASHTO M36-86, The American Association of State Highway and Transportation Officials, Washington, DC. "Corrugated Steel Pipe, Metallic Coated for Sewers and Drains," 1989. ASTM A 760-89, American Society for Testing and Materials, Philadelphia, PA. "Corrugated Steel Pipe, Polymer Precoated for Sewers and Drains," 1986. AASHTO M245-86, The American Society of State Highway and Transportation Officials, Washington, DC. "Corrugated Steel Pipe, Polymer Precoated for Sewers and Drains," 1988. ASTM A 762-88, American Society for Testing and Materials, Philadelphia, PA. "CRC Handbook of Chemistry and Physics," 1984. 64th Edition, CRC Press, Inc., Boca Raton. Florida. "Durability of Drainage Pipe," 1978. National Cooperative Highway Research Program Synthesis of Iighway Practice 50, Transportation Research Board, Washington, DC. Dye, J. F. 1952, "Calculation of Effect of Temperature on the pH, Free Carbon Dioxide and the Three Forms of Alkalinity," Volume 44, pages 356-372, American Water Works Association, Baltimore, MD, Gatos, H. C. 1956. "Inhibition of Metallic Corrosion in Aqueous Media," Symposium of Corrosion Fundamentals, University of Tennessee Press, Knoxville. TN. Handbook of Steel Drainage and Highway Construction Products, 1983. American Iron and Steel Institute, Washington, DC. Hatch, G. B. and Rice, O. 1959. "Influence of Water Composition on the Corrosion of Steel," Volume 51, pages 719-727, American Water Works Association, Baltimore, MD. A2 Haviland, J. E., Bellair, P. J., and Morrell, V. D. 1968, "Durability of Corrugated Metal Culverts," Highway Research Record 242, Highway Research Board, Washington, DC. Hickman, R. L. and Edwards, R. E. 1987. "Evaluation of CMP Invert Protection Products Under Different Bedloads," Department of Transportation, Sacramento. CA. Highlands, K. L. and Maurer, D. A. 1987 (June). "Field Evaluation of Metallic Coated Corrugated Steel Pipe," Report No. PA-86-049+84.105, Pennsylvania Department of Transportation, Harrisburg, PA. Hirsch, C. M. 1984. "Durability of Polymer -Coated Corrugated Steel Pipe," Transportation Research Record 1001, pages 9-13, Transportation Research Board, Washington, DC. Hoover, C. P. 1938. "Practical Application of the Langelier Method," Volume 30, American Water Works Association, Baltimore, MD. Hurd, J. 0. 1984, "Field Performance of Concrete and Corrugated Steel Pipe Culverts and Bituminous Protection of Corrugated Steel Pipe Culverts," Transportation Research Record 1001, pages 40-48, Transportation Research Board, Washington, DC. Hurd, J. 0. 1984. "Field Performance of Protective Linings for Concrete and Corrugated Steel Pipe Culverts," Transportation Research Record 1001, pages 35-40, Transportation Research Board, Washington, DC. "Internal Corrosion of Water Distribution Systems," 1985. Cooperative Research Report, American Water Works Association Research Foundation, Denver, CO. Jacobs, K. M. 1982 (June). "Durability of Drainage Structures," Report No. BP-82(547). Maine Department of Transportation for Federal Highway Administration, Washington, DC. Jacobs, K. M. 1984. "Durability of Drainage Structures," Transportation Research Record 1001, pages 14-26, Transportation Research Board, Washington, DC. Kinchen, R. W. 1980. "Evaluation of the Durability of Metal Drainage Pipe," Transportation Research Record 762, pages 25-32, Transportation Research Board, Washington, DC. Koelliker, J. Y , Best, C. H. and Lin, A. N. 1989 (August). "Inspection and Evaluation of Principal Spillway Conducts in Kansas," Kansas State University, Manhattan, KS. Krizek, R. J. and Kay, N. J. 1972. "Material Properties Affecting Soil - Structure Interaction of Underground Conducts," Highway Research Record 413, Highway Research Board, Washington, DC_ A Larson, T. E. and Skold, R.V. 1958 (June). "Laboratory Studies Relating Mineral Quality of Water to Corrosion of Steel and Cast Iron," Corrosion Langelier, W. F. 1946. "Chemical Equilibria in Water Treatment," Volume 38, pages 169-178, American Water Works Association, Baltimore, MD. Langelier, W. F. 1946. "Effect of Temperature on the pH of Natural Waters," Volume 38, pages 179-185, American Water Works Association, Baltimore, MD. Langelier, W. F. 1936. "The Analytical Control of Anti -Corrosion Water Treatment," Volume 28, American Water Works Association, Baltimore, MD. Lindberg, R. I. 1967. "Method of Estimating Corrosion of Highway Culverts by Means of Polarization Curves," Highway Research Record 204, page 1, Highway Research Board, Washington, DC. Lowe, T. A. and Koepf, A. H. 1964. "Corrosion Performance of Aluminum Culvert," Highway Research Record 56, page 98, Highway Research Board, Washington, DC. Lowe, T. A., Vater taus, R. H., Lindberg, R. I. and Lawrencs, L. R. 1969. "Corrosion Evaluation o'E Aluminum Culvert Based on Field Performance," Highway Research Record 262, Highway Research Board, Washington, DC. McCauley, R. F. and Abdullah, M. 0. 1958. "Carbonate for Pipe Protection," Volume 50, page 1419, American Water Works Association, Baltimore, MD. McKee, A. B. and Brown, R. H. 1947. "Resistance of Aluminum to Corrosion in Solutions Containing Various Anions and Cations," Corrosion, Volume 3, No. 12, pages 595-612, National Association of Corrosion Engineers, Houston, TX. Meacham, D. G., Hurd, J. 0, and Shisler, W. W. 1982 (January). "Ohio Culvert Durability Study," Report ODOT/L&D/82-1, Ohio Department of Transportation, Columbus, OH. "Method for Estimating the Service Life of Steel Culverts," 1978. California Test 643, Department of Transportation, Division of Construction, Sacramento, CA. "Modern Sewer Design," 1990, American Iron and Steel Institute, Washington, DC. Morris, G. E. and Bednar, L. 1984, "Comprehensive Evaluation of Aluminized Steel Type 2 Pipe Field Performance," Transportation Research Record 1001, pages 49-59, Transportation Research Board, Washington, DC. Nordlin, E. F. and Stratfull, R. F. 1965. "A Preliminary Study of Aluminum as a Culvert Material," Highwav Research Record 95, page 1, Highway Research Board, Washington, DC. A4 Poche, J. J. and Clement, K. A. 1989 (August). "Comparative Laboratory Testing of Aramid Fiber Bonded Corrugated Galvanized Steel and Asbestos Bonded Corrugated Galvanized Steel," Louisiana Department of Transportation, Baton Rouge, LA. "Post -Coated and Lined Corrugated Steel Sewer and Drainage Pipe (Bituminous or Concrete)," 1989, ASTM A 849-89, American Society for Testing and Materials, Philadelphia, PA. Potter, J. C. 1990 (March/April). "Aluminum Coated Corrugated Steel Pipe Field Performance," Journal of Transportation Engineering, American Society of Civil Engineers, Volume 116, Number 2, pages 145-152, New York, NY_ Potter, J. C. 1986 (November). "Evaluation of Buried Concrete -Lined Corrugated Metal Pipe," Miscellaneous Paper CL 86-33, US Army Engineer Waterways Experiment Station, Vicksburg, MS. Potter, J. C. 1988 (February). "Life Cycle Cost for Drainage Structures," Technical Report GL 88-2, US Army Engineer Waterways Experiment Station, Vicksburg, MS. Potter, J. C. 1988 (November). "Quantative Analysis of FHWA Aluminized Type 2 CSP Field Test Installations," Memorandum For Federal Highway Administration, HDF-12, Washington, DC. Pyskadlo, R. M. 1989 (May). "Performance of Polymer -Coated and Bituminous - Coated -and -Paved Corrugated Steel Pipe," Report FHWA/NY/SR-89-94, New York State Department of Transportation for Federal Highway Administration, Washington, DC. Pyskadlo, R. M. and Ewing, J. P. 1987 (September). "Coatings for Corrugated Steel Pipe," Report FHWA/NY/SR-87/90, New York State Department of Transportation for Federal Highway Administration, Washington, DC. Pyskadlo, R. M. and Renfrew, W. W. 1984 (July). "An Overview of Polymer Coatings for Corrugated Steel Pipe in New York," Report FHWA/NY/SR-84/79, New York State Department of Transportation for Federal Highway Administration, Washington, DC. Pyskadlo, R. M. and Renfrew, W. W. 1984. "Overview of Polymer Coatings for Corrugated Steel Pipe in New York," Transportation Research Record 1001, pages 21-26, Transportation Research Board, Washington, DC. Renfrew, W. W. 1984. "Durability of Asphalt Coating and Paving on Corrugated Steel Culverts in New York," Transportation Research Record 1001, pages 26-34, Transportation Research Board, Washington, DC. Renfrew, W. W. 1984 (July). "Durability of Asphalt Coating and Paving on Corrugated Steel Culverts in New York," Report FHWA/NY/SR-84/80, New York State Department of Transportation for Federal Highway Administration, Washington, DC. AS Ring, G. W. 1984. "Culvert Durability: Where Are We?" Transportation Research Record 1001, pages 1-9, Transportation Research Board, Washington, DC. Sarikelli, S. and Simon, A. L. 1980 (December). "Field and Laboratory Evaluation of Energy Dissipators for Culvert and Storm Outlets, Volume II Field Performance of Corrugated Metal Culverts," Ohio-DOT-03-79, Department of Civil Engineering, University of Akron for Ohio Department of Transportation, Columbus, OH. Schwerdtfeger, W. J. 1966. "Soil Resistivity as Related to Underground Corrosion and Cathodic Protection,-" Highway Research Record 110, page 20, Highway Research Board, Washington, DC. Senf, D. F. and Bednar, L. 1989 (October). "Durability of Plain Galvanized Steel Drainage Pipe in South America" Criteria for Selection of Plain Galvanized," Armco, Inc., Middletown, OH. Shrier, L. L. 1977. "Corrosion," Volume 1, Butterworth (Publishers) Inc. Woburn, MA. "Standard Methods for the Examination of Water and Wastewater," 1985. American Public Health Association (Printed by Port City Press, Baltimore, MD) Washington, DC. Stavros, A. J. 1984. "Aluminum -zinc Corrugated Steel Pipe: A Performance Study," Transportation Research Record 1001, pages 69-76, Transportation Research Board, Washington, DC. "Steel Sheet, Aluminum -Coated (Type 2) for Corrugated Steel Pipe," 1984. AASHTO M274-84, The American Association of State Highway and Transportation Officials, Washington, DC. "Steel Sheet, Aluminwn-Coated Type 2 for Storm Sewer and Drainage Pipe," 1984. ASTM A 819-84, American Society for Testing and Materials, Philadelphia, PA. "Steel Sheet, Aluminum -Zinc Alloy Coated by the Hot -Dip Process, General Requirements," 1989. ASTM A 792-89, American Society for Testing and Materials, Philadelphia, PA. "Steel Sheet, Aluminum -Zinc Alloy Coated by the Hot -Dip Process for Storm Sewer and Drainage Pipe," 1988. ASTM A 806-88, American Society for Testing and Materials, Philadelphia, PA. "Steel Sheet, Cold -Rolled, Aluminum -Coated Type 1 and Type 2," 1988. ASTM A 463-88. American Society for Testing and Materials, Philadelphia, PA. "Steel Sheet, Metallic -Coated and Polymer Precoated for Corrugated Steel Pipe," 1986. AASHTO M246-86, The American Association of State Highway and Transportation Officials, Washington, DC. d "Steel Sheet, Metallic -Coated and Polymer Precoated for Corrugated Steel Pipe," 1986. ASTM A 742-86_ American Society for Testing and Materials, Philadelphia, PA. "Steel Sheet, Zinc and Aramid Fiber Composite Coated for Corrugated Steel Sewer Culvert and Underdrain Pipe," 1988. ASTM A 885-88, American Society for Testing and Materials, Philadelphia, PA. Stratfull, R. F. 1980. "Modern Sewer Design," Chapter 7, pages 221-239, "Durability," American Iron and Steel Institute, Washington, DC. "Study of Use, Durability, and Cost of Corrugated Steel Pipe on the Missouri Highway and Transportation Department's Highway System," 1984 (May). Study Number MR 87-1, Missouri Highway and Transportation Department, Jefferson City, MO. Stum, W. 1960. "Investigations of Corrosive Behavior of Waters," Proceedings of the American Society of Civil Engineers, Sanitary Engineering Division, Volume 86, No. SA6, Ann Arbor, MI. Sudol, J. J. 1982 (September). "Pipe Coating Study," Indiana Department of Highways, West Lafayette, IN. Summerson, T. J. 1984. "Corrosion Resistance of Aluminum Drainage Products: The First 25 Years," Transportation Research Record 1001, Transportation Research Board, Washington, DC. Summerson, T. J. 1984 (June). "1981 Survey of Type II Aluminized Steel Riveted Culvert Test Sites," Kaiser Aluminum and Chemical Corporation, Pleasanton, CA. Swanson, H. N. and Donnelly, D. E. 1977 (September). "Performance of Culvert Materials in Various Colorado Environments," Report No. CDOH-P&R-R-77-7, Colorado Division of Highways, Denver, CO. Temple, W. H. and Cumbaa, S. L. 1986. "Evaluation of Metal Drainage Pipe Durability After Ten Years," Transportation Research Record 1087, pages 7-14, Transportation Research Board, Washington, DC. Temple, W. H., Cumbaa, S. L., and Gueho, B. J. 1985 (March). "Evaluation of Drainage Pipe by Field Experimentation and Supplementary Laboratory Experimentation," Report FHWA/I.A-85/174, Louisiana Department of Transportation and Development for Federal Highway Administration, Washington, DC. Tillmans, J. 1932. "Die Chemische Untersuchung Von Wasser and Abrvasser," 2nd Edition, Wilhelm Knapp Halle (Saale). Tupac, G. J. 1987 (September). "Corrosion Survey on Corrugated Steel Culvert Pipe," to State of California Department Transportation for USS-Posco, USX, Pittsburgh, PA. A7 US Department of Transportation, Federal Highway Administration, 1988 (August). "Interim Direct Federal Design Guidance on Drainage Pipe Alternative Selection," Washington, DC. Welch, B. H. 1976. "Pipe Corrosion and Protective Coatings," Transportation Research Record 604, pages 20-24, Transportation Research Board, Washington, DC. Worley, H. E. and Crumpton, C. F. 1972. "Corrosion and Service Life of Corrugated Metal Pipe in Kansas," Highway Research Record 412, pages 35-40, Highway Research Board, Washington, DC. Zeid, S. Y. and Macy, M. S. 1985 (April). "Durability of Bituminous -Lined Corrugated Steel Pipe Storm Sewers," Report FHWA/OH-85/003, Malcolm Pirnie, Inc. for Ohio Department of Transportation, Columbus, OH. A8 http:I/www.usace.army.mjli'publications/eng- see pdf pg 6 regarding service life CECW-ED Department of the Amy EM 1110-2-2909 U.S. Army Corps of Engineers Engineer Manual Washington, DC 20314-1000 31 October 1997 1110-2-2902 (Original) 31 March 1998 (Change 1) Engineering and Design CONDUITS, CULVERTS, AND PIPES Distribution Restriction Statement Approved for public release; distribution is unlimited. DEPARTMENT OF THE ARMY U.S. Army Corps of Engineers CECW-ED Washington, DC 20314-1000 Manual No. 1110-2-2902 Engineering and Design CONDUITS, CULVERTS, AND PIPES 1. This Change 1 to EM 11I0-2-2902, 31 October 1997: a. Corrects a subscript in Equation 3-2, Chapter 3. EM 1110-2-2902 Change 1 31 March 1998 b. Adds information about polymer coatings and updates ASTM References in Chapter 4. c. Changes the terminology for coupling bands in Chapter 4. d. Updates ASTM References in Appendix A. e. Changes variable name and value for FS and the variable name for D of the sample problem in Appendix B. f. Gives new values for the variable Do o, of Equation 3-2 in the sample problem in Appendix B. 2. Substitute the attached pages as shown below: Chapter Remove page Insert page 3 3-5 and 3-6 3-5 and 3-6 4 4-1 thru 4-6 4-1 thm 4-6 Appendix A A-1 thru A-7 A-1 thru A-7 Appendix B B-7 and B-8 B-7 and B-8 3. File this change sheet in front of the publication for reference purposes. FOR THE COMMANDER: DEPARTMENT OF THE ARMY EM 1110-2-2902 U.S. Army Corps of Engineers CECW-ED Washington, DC 20314-1000 7Mit 9 No. 1110-2-2902 31 October 1997 Engineering and Design CONDUITS, CULVERTS, AND PIPES 1. Purpose. This manual provides (a) guidance on the design and construction of conduits, culverts, and pipes, and (b) design procedures for trench/embankment earth loadings, highway loadings, railroad loadings, surface concentrated loadings, and intemal/external fluid pressures. 2. Applicability. This manual applies to all USACE commands having civil works responsibilities. 3. General. Reinforced concrete conduits and pipes are used for dams, urban levees, and other levees where public safety is at risk or substantial property damage could occur. Corrugated metal pipes are acceptable through agricultural levees where conduits are 900-mm (36-in.) diameter and where levee embankments are not higher than 4 m (12 ft) above the conduit invert. Inlet structures, intake towers, gate wells, and outlet structures should be concrete, or corrugated metal structures may be used in agricultural and rural levees. Life cycle cost studies are required where corrugated metal pipes are used. 4. Distribution. This manual is approved for public release; distribution is unlimited. FOR THE COMMANDER: 3alt' J� OTIS WILLIAMS Colonel, Corps of Engineers Chief of Staff This manual supersedes EM 1110-2-2902 dated 30 November 1979. DEPARTMENT OF THE ARMY EM 1110-2-2902 U.S. Army Corps of Engineers CECW-ED Washington, DC 20314-1000 Manual No. 1110-2-2902 31 October 1997 Engineering and Design CONDUITS, CULVERTS, AND PIPES Table of Contents Subject Paragraph Page Subject Paragraph Page Chapter 1 Chapter 4 Introduction Corrugated Metal Pipe for Purpose and Scope ............... 1-1 14 Rural Levees and Culverts Applicability .................... 1-2 1-1 General ... ....................4-1 4-1 References ..................... 1-3 1-1 Materials .. . 4 ........ 4 2; v Life Cycle Design ................ 1-4 1-1 Installation .................... 4-3 4-4 Supportive Material ............... 1-5 1-2 Loadings ...................... 4-4 4-4 General ........................ 1-6 1-2 Methods of Analysis .............4-5 4-4 Joints .........................4-6 4-5 Chapter Camber .......................4-7 4-5 Cast -in -Place Conduits for Dams General ........................ 2-1 2-1 Chapter Materials ....................... 2-2 2-2 Concrete Culverts Installation ..................... 2-3 2-2 General ....................... 5-1 5-1 Loadings ....................... 2-4 2-2 Materials ...................... 5-2 5-1 Special Conditions ............... 2-5 2-9 Installation .................... 5-3 5-1 Methods of Analysis .............. 2-6 2-9 Loadings ...................... 5-4 5-1 Reinforcement ................... 2-7 2-9 Methods of Analysis ............. 5-5 54 Joints .......................... 2-8 2-11 Joints .......... ............... 5-6 5-5 Waterstops ..................... 2-9 2-11 Camber .............. ......... 5-7 5-7 Camber ........................ 2-10 2-11 Chapter 6 Chapter 3 Plastic Pipe for Other Circular Reinforced Concrete Pipe Applications for Small Dams and Levees General ....................... 6-1 6-1 General ........................ 3-1 3-1 Materials ...................... 6-2 6-1 Materials ....................... 3-2 3-1 Installation .................... 6-3 6-2 Installation: Small Dams .......... 3-3 3-1 Loadings ...................... 6-4 6-6 Materials: Levees ................ 3-4 3-4 Methods of Analysis 6-5 6-6 Installation: Levees .............. 3-5 3-5 Joints ......................... 6-6 6-9 Loadings ....................... 3-6 3-6 Camber ....................... 6-7 6-9 Methods of Analysis .............. 3-7 3-6 Joints .......................... 3-8 3-9 Camber ........................ 3-9 3-10 EM 1110-2-2902 31 Oct 97 Subject Paragraph Page Chapter 7 Ductile Iron Pipe and Steel Pipe for Other Applications General........................ Materials ....................... Installation ..................... Loadings ....................... Methods of Analysis .............. Joints .......................... Camber ........................ 7-I 7-2 7-3 7-4 7-5 7-6 7-7 7-1 7-1 7-I 7-I 7-1 7-2 7-2 Chapter 8 Pipe Jacking General ........................ 8-1 8-1 Materials ....................... 8-2 8-1 Installation ..................... 8-3 8-1 Loadings on Installed Pipe ......... 8-4 8-1 Subject Appendix A References Appendix B Design Examples Appendix C Evaluation and Inspection of Existing Systems Appendix D Repair of Existing Systems Paragraph Page Appendix E Metric Conversion Data Sheet Chapter 1 Introduction 1-1. Purpose and Scope This manual provides (a) guidance on the design and con- struction of conduits, culverts, and pipes, and (b) design procedures fortrench/embankment earth loadings, high- way loadings, railroad loadings, surface concentrated loadings, and internal/external fluid pressures. 1-2. Applicability This manual applies to HQUSACE elements and USACE commands, districts, laboratories, and field operating activities having civil works responsibilities. 1-3. References The references listed in Appendix A contain accepted methods to design conduits, culverts, and pipes which may be used when specific guidance is not provided in this manual. Related publications are also listed in Appendix A. 1-4. Life Cycle Design a. General. During the design process, selection of materials or products for conduits, culverts, or pipes should be based on engineering requirements and life cycle performance. This balances the need to minimize first costs with the need for reliable long-term perform- ance and reasonable future maintenance costs. b. Project service life. Economic analysis used as a part of project authorization studies usually calculates costs and benefits projected for a 50- or 75-year project life. However, many USACE projects represent a major infrastructure for the Nation, and will likely remain in service indefinitely. For major infrastructure projects, designers should use a minimum project service life of 100 years when considering life cycle design. C. Product service life. Products made from differ- ent materials or with different protective coatings may exhibit markedly different useful lives. The service life of many products will be less than the project service life, and this must be considered in the life cycle design pro- cess. A literature search (Civil Engineering Research Foundation 1992) reported the following information on EM 1110-2-2902 31 Oct 97 product service lives for pipe materials. In general, con- crete pipe can be expected to provide a product service life approximately two times that of steel or aluminum. However, each project has a unique environment, which may either increase or decrease product service life. Significant factors include soil pH and resistivity, water pH, presence of salts or other corrosive compounds, ero- sion sediment, and flow velocity. The designer should investigate and document key environmental factors and use them to select an appropriate product service life. (1) Concrete. Most studies estimated product service life for concrete pipe to be between 70 and 100 years. Of nine state highway departments, three listed the life as 100 years, five states stated between 70 and 100 years, and one state gave 50 years. (2) Steel. Corrugated steel pipe usually fails due to corrosion of the invert or the exterior of the pipe. Pro- perly applied coatings can extend the product life to at least 50 years for most environments. (3) Aluminum. Aluminum pipe is usually affected more by soil -side corrosion than by corrosion of the invert. Long-term performance is difficult to predict because of a relatively short history of use, but the designer should not expect a product service life of greater than 50 years. (4) Plastic. Many different materials fall under the general category of plastic. Each of these materials may have some unique applications where it is suitable or unsuitable. Performance history of plastic pipe is limited. A designer should not expect a product service life of greater than 50 years. d. Future costs. The analysis should include the cost of initial construction and future costs for mainte- nance, repair, and replacement over the project service life. Where certain future costs are identical among all options, they will not affect the comparative results and may be excluded from the calculations. For example, costs might be identical for normal operation, inspection, and maintenance. In this case, the only future costs to consider are those for major repairs and replacement. Where replacement will be necessary during the project service life, the designer must include all costs for the replacement activities. This might include significant costs for construction of temporary levees or cofferdams, as well as significant disruptions in normal project operations. 1-1 EM 1110-2-2902 31 Oct 97 1-5. Supportive Material Appendix B presents design examples for conduits, cul- verts, and pipes. Appendixes C and. D suggest outlines for evaluation of existing systems and repair of existing systems, respectively. Appendix E is a conversion factor table for metric units. 1-6. General Reinforced concrete conduits are used for medium and large dams, and precast pipes are used for small dams, urban levees, and other levees where public safety is at risk or substantial property damage could occur. Corru- gated metal pipes are acceptable through agricultural levees where the conduit diameter is 900 mm (36 in.) and when levee embankments are no higher than 4 in (12 fl) above the conduit invert. Inlet structures, intake towers, gate wells, and outlet structures should be constructed of cast -in -place reinforced concrete. However, precast con- crete or corrugated metal structures may be used in agri- cultural and rural levees. Culverts are usually used for roadway, railway, and runway crossings. a. Shapes. Conduits are closed shaped openings used to carry fluids through dams, levees, and other embankments. Conduit shapes are determined by hydrau- lic design and installation conditions. Typical shapes include circular, rectangular, oblong, horseshoe, and square sections. Circular shapes are most common. Rectangular or box -shaped conduits are generally used for large conduits through levees and for culverts carrying waterways under roads or railroads. ]Multiple cell config- urations are commonly box shaped. b. Loads. Conduit loadings account for earth loads, surface surcharge loads, vehicle loads, external hydrostatic pressures, and internal fluid pressures. Surface surcharge loads can be used to account for the reservoir pool water above a finished grade. Internal fluid pressure is deter- mined by the hydraulic design of the conduit and is a concern when greater than the external pressures. c. Materials. Construction includes cast -in -place concrete, precast concrete, steel, ductile iron, aluminum, 1-2 and plastic. In general, concrete conduits are designed as rigid conduits, and the other materials are designed as flexible conduits. In flexible conduit design, the vertical loads deflect the conduit walls into the surrounding soils, thereby developing the strength of the conduit through soil -structure interaction. Therefore, control of the back - fill compaction around flexible conduits is critical to the design, Controlled backfill placement for either type of onduit minimizes pipe deflection, maintains joint integrity, and reduces water piping. d. Joints. Joints in conduits passing through dams and levees must be watertight and flexible to accommo- date longitudinal and lateral movements. Because leaking joints will lead to piping and to the premature failure of the conduit and the embankment, designers need to con- trol conduit deflections, conduit settlements, and joint movements. Maintaining joint integrity in conduits pass- ing through dams and levees is critical. Improperly installed pipe causes joints to leak, allows soil fines to pass through the conduit joints into the conduit, or allows internal water to pass through the conduit joints and along the outside of the conduit (piping). e. Foundation and piping. The three common foundation problems encountered in conduit design are water piping along the outside of the conduit, the piping of soil into the conduit, the migration of soil fines into a well -washed crushed rock foundation material. Soil migration problems often lead to sink holes, which can cause embankment failure due to piping. In accordance with EM 1110-2-1913, a 450-mm (18-in.) annular thick- ness of drainage fill should be provided around the land - side third of any conduit (Figure 1-1) regardless of type of conduit to be used, where the landside zoning of an embankment or levee does not provide for such drainage. For conduit installations with an embankment or levee foundation, the 450-min (18-in.) annular thickness of drainage fill shall be provided and shall include provisions for a landside outlet through a blind drain to the ground surface at the levee toe, connection with pervious under - seepage collection features, or an annular drainage fill outlet to the ground surface around a manhole structure. RIVERSIDE IANDSIDE Ls Dom or Levee LS 3 A Drolnoge Fill q a v 9 450mm UB'1 o drainage layer Sect A —A Figure 1-1. Drainage fill along conduit EM 1110-2-2902 31 Oct 97 1-3 Chapter 2 Cast -in -Place Conduits for Dams 2-1. General The selection of the most economical conduit cross sec- tion must depend on the designer's judgment and the consideration of all design factors and site conditions for each application. For fills of moderate height, circular or rectangular openings will frequently be the most practica- ble because of the speed and economy obtainable in design and construction. For openings of less than about 5.6 m2 (60 ft2), a single rectangular box probably will be most economical for moderate fills up to about 18.3 in (60 ft). However, a rectangular conduit entrenched in rock to the top of the conduit may be economical for higher fills since the applied vertical load need be only the weight of the earth directly above with no increase for differential fill settlement. The ratio of height to width should be about 1.50 to accommodate the range of load- ing conditions economically. Where there is a battery of outlet gates, a multiple -box shape is sometimes economi- cal where acceptable from a hydraulic standpoint. a. Single conduits. For a single conduit of more than about 5.6-m2 (60-ft2) area and with a till height over 18.3 in (60 ft), it will generally be found economical to use a section other than rectangular for the embankment loading (Condition III). The circular shapes are more adaptable to changes in loadings and stresses that may be caused by unequal fill or foundation settlement. For cases in which the projection loading condition applies, no material stress reduction results from the provision of a variable cross section. These structures should be formed as shown in Figure 2-1 and should be analyzed as a ring of uniform thickness. While these sections show varia- tions in thickness in the lower half of the conduit due to forming and other construction expedients, such variations may be disregarded in the design without appreciable error. b. Oblong sections. The oblong section shown in Figure 2-1 is formed by separating two semicircular sec- tions by short straight vertical wall sections. The oblong section generally achieves maximum economy of mate- rials by mobilizing more of the relieving fill pressure. The proportions should be selected carefully, and the tangent -length -to -radius ratio will usually be between 0.5 and 1.0. The conduit design should cover a range of pos- sible loading conditions, from initial or construction con- dition to the long-time condition. Here also, a geologist EM 1110-2-2902 31 Oct 97 R Assume0 des/gn 2 sedW MODIFIED CIRCULAR SECTION i i Nip 1, i N Be HORSESHOE SECTION i T iP i Assumed i Geslg9n � �- 2 0236 B� OBLONG SECTION Figure 2-1. Typical cast -In -place conduits or soils engineer should be consulted before final determi- nation of the base shape of a conduit. c. Horseshoe sections. The "horseshoe" section in Figure 2-1 is generally less economical than the oblong and is therefore not often used. Its stress distribution is not as desirable as that of the circular or oblong section, and shear stirrups may be required in the base. It may be practicable, however, for some foundation conditions where the fill height is low. d. Interbedded foundations. It may be difficult to shape the foundation excavation when in closely bedded, flat -lying shale, or when in rock with frequent shale inter - beds. For this condition, it may be economical to exca- vate the foundation level and backfill to the desired shape with a low-cement�content concrete. A geotechnical engineer should be consulted to help develop the 2-1 EM 1110-2.2902 31 Oct 97 excavation plan. Excavation drawings should show the pay excavation lines and not the actual excavation lines. For a conduit under a dam, the designer should show the actual excavation lines rather than the pay excavation lines and the contractor should limit excavation to the actual excavation lines. 2-2. Materials a. Concrete. Minimum compressive strength 28 MPa (4,000 psi) air entrained. b. Reinforcement. Minimum yield strength, Grade 400 MPa (60,000 psi). 2-3. Installation Conduits through dams are cast directly against the soil or rock and, therefore, bedding is not a design consideration. When overexcavadon of the foundation materials is required, concrete fill should be used to maintain proper conduit grade. All foundation materials for cast -in -place conduits should be reviewed by a geotechnical engineer. 2-4. Loadings Typical conduit loads are shown in Figure 2-2. The con- duit supports the weight of the soil and water above the crown. Internal and external fluid pressures and lateral soil pressures may be assumed as uniform loads along the horizontal axis of the conduit when the fluid head or fill height above the crown is greater than twice the conduit diameter or span. Foundation pressures are assumed to act uniformly across the full width of cast -in -place con- duits. Uplift pressures should be calculated as uniform pressure at the base of the conduit when checking flotation. a. Groundwater and surcharge water. Because of the ratio of vertical to horizontal pressure, the most severe loading condition will generally occur when the reservoir is empty and the soil is in a natural drained condition. However, the following loads occur where there is groundwater and/or surcharge water. (1) Vertical pressure. Use Equation 2-1 to determine vertical pressure due to the weight of the natural drained soil above the groundwater surface, the weight of the submerged soil below the groundwater surface, and the weight of the projected volume of water above the con- duit, including any surcharge water above the fill surface. 2-2 W. = Yd Hd or Ww=Yd Hd'Ys Hs (2-1) W. = Yw H. (Ys- Yw) Hs where Wµ, = vertical pressure due to prism of soil above pipe, N/mZ (psf) Y = soil unit weight; d = dry, s = saturated, w = water, N/m3 (pef) H = soil height; d = dry, s = saturated soil, m (ft) Hh, = water height above the point of interest, m (ft) (2) Horizontal pressure. Horizontal pressure from the lateral earth pressure is obtained by using soil weights for the appropriate moisture conditions and full hydro- static pressure. b. Internal water pressure. Internal water pressure should be considered but will seldom govern the design for the usual type of outlet works. However, internal pressures must be analyzed as indicated in Equation 2-2 for pressure conduits for interior drainage in local protec- tion projects. Wi = Yw (HG t r) (2-2) where Wi = internal pressure at point of interest, N/m2 (psf) Yw = unit weight of water, 9.8 kN/m3 (62.4 pef) HG = hydraulic gradient above point of interest, m (ft) r = inside radius of conduit, m (ft) EM 1110-2-2902 31 Oct 97 Trench condition .' Hydraullc Reservoir grade line 1 — condition I � i ii, j �! Load plane Xz �i I LATERAL PRESSURE Foundation INTERNAL PRESSURE pressure uplift When the height of fill Is greater than twice the trench width use the- average horizontal pressure computed at the pipe centerline Figure 2-2. Typical conduit loadings C. Concentrated live loads. (1) Vertical pressure. Because soil conditions vary, designers can expect only a reasonable approximation when computing vertical pressures resulting from concen- trated surface loads. The Boussinesq method is com- monly used to convert surface point loads to vertical stress fields through the geometric relationship shown in Equation 2-3. This equation may be used for all types of soil masses including normally consolidated, overconsoli- dated, anisotropic, and layered soils. Stresses calculated by using this method are in close agreement with meas- ured stress fields, and examples for using Equation 2-3 are shown in Figure 2-3. Wr - 3Pz3 (2_3) 2aR5 where Wr = vertical pressure due to concentrated load, N/m2 (psf) P = concentrated load, N (lb) z = depth to pressure surface, m (ft) R = radial distance to pressure surface, in (ft) (2) Horizontal pressure. Lateral loads caused by vehicles can be safely ignored due to their transient nature. However, a minimum lateral pressure of 0.005 of the wheel load for vehicles to a depth of 2.4 in (8 ft) should be considered in accordance with American Soci- ety for Testing and Materials (ASTM) C 857. For stationary surcharge loads, a lateral pressure can be calcu- lated by using a Boussinesq equation such as Equation 2-4. 2-3 EM 1110-2-2902 31 Oct 97 P Given: P-44.5 kN 0,000 lbs.) z•092 In (3 ft) r-0.61 In (2 ft) R- rz+g b-052 m (1.7 ft) radius of a circular area L-B-092 m (3 ft) d/menslon of a square area L•Long side of rectangular area MINIMUM LATERAL PRESSURES pe = 0.4 we (AREA) pe 0.5 or I.Owc (COE) LOAD PLANE PRESSURE METHOD FORMULA AT POINT CENTER Kpo (psf) Kpo IW) BOUSS/NEO we • 2 Rs 103 f215/ 25J(525) SWARE AREA FIGURE 2-5 105 (220) 18.4 (384) FIGURE 2£ 105 (220) 183 (383) CIRCULAR l7B (372) Wc" +z L+zl 13J(275) 13J(275) SIMPLIFIED ,�2 P WC • �y q AASHTO'J 2 Pyromld (2 f0 172 r359) 172 (359) 75 minlmum cover Figure 2-3. Typical live load stress distribution P 3zr2 _ (1 - 2N) (2-4) P` 21t R5 R(R + z) where 111 PC = horizontal pressure from concentrated load, N/mZ (psf) r = surface radius from point load P, in (ft) R = radial distance to point in question, in (ft) P = Poisson's ratio, 0.5 for saturated cohesive soils or 0.2 to 0.3 for other soils Consult a geotechnical engineer for lateral loads from other surcharge conditions. (3) Wheel loads. For relatively high fills, Equa- tion 2-3 will give reasonably accurate results for highway and railroad wheel loads and the loads on relatively small footings. However, where the conduit is near the surface or where the contact area of the applied load is large, 2-4 these loads must be divided into units for a more accurate analysis. The use of influence charts as developed by Newmark (1942) will be helpful in computing the stress due to loads on relatively large and irregular areas. d. Backfill. The behavior of the soil pressures transmitted to a conduit or culvert by the overlying fill material is influenced by the physical characteristics and degree of compaction of the soil above and adjacent to the conduit or culvert as well as the degree of flexibility and the amount of settlement of the conduit or culvert. The effect of submergence in the backfill must also be considered as indicated in Figure 2-2. Direct measure- ments of such pressures have been made for small - diameter pipes under relatively low fills. Until more data are available, the following loading should be used for rigid conduits and culverts for dams and levees and outlet conduits for interior drainage. The effect of submergence in the backfill must be considered. The three typical conduit installation conditions are trench, trench with superimposed fill, and embankment. Terms for these loading conditions arc defined in Figure 2-4. Ground EM 1110-2-2902 31 Oct 97 Hc • l0 500mm (35 ft) lnslde Dlometer - I200mm W-0') bs - 2100mm (7'-0') r • 17.3 kN/m3(I10 pcf) Ordlnory Cloy Class B Bedding DLOq - 289 kN/m (1,984 plf) TRENCH (CONDITION I) H� - l0 500mm (35 ft) lnslde Dlometer-1200mm W-0') Ld - 2100mm 0-M Y -17J kN/mJ(110 pcf) p'•!A Class B BeddIng DLOA0 - 33.3 kNIm (2267 plf) TRENCH WITH SUPERIMPOSED FILL (CONDITION II ) de Ho • 10 500mm (35 ft) lnslde Dlometer-1200mm (41-0') a' -17.3 kNIM3(110 pcf) Ordinary Soll p•07 Class B Beddlnq DLOAD • 43.3 kN/m (2,970 pff) Ground EMBANKMENT (CONDITION HI) Figure 2-4. Loading conditions for conduits 2-5 EM 1110-2-2902 31 Oct 97 (1) Trench with no superimposed fill (Condition I). (a) Loads from the trench backfill condition are applied to those structures that are completely buried in a trench with no superimposed fill above the top of the trench. To satisfy this condition, the width of the trench measured at the top of the conduit should be no greater than one and one-half times the overall width of the con- duit, and the sides of the ditch above the top of the con- duit should have a slope no flatter than one horizontal to two vertical. The total dead load of the earth at the top of the conduit should be computed as the larger of the two values obtained from Equations 2-5 through 2-7. or We=CdYB2 d µ'e =y BcH -2 Kp • B 1-e d Cd = 2 Kµ' where applied uniformly over the height of the conduit. When He < 2Bd, the horizontal pressure in N/m2 (psf) at any depth should be computed using Equation 2-8. Pe = YH tang (45 - ±) = KJH (2-8) l 2 where Pe = horizontal earth pressure, N/m2 (psf) y = unit weight of fill, N/m3 (pcf) (2 5) = angle of internal friction of the fill material, degrees Ka = active pressure coefficient, N (lb) (2 6) (c) In most cases, the unit weight and the internal friction angle of the proposed backfill material in dry, natural drained, and submerged conditions should be determined by the laboratory and adapted to the design. However, where economic conditions do not justify the (2-7) cost of extensive investigations by a soils laboratory, appropriate values of unit weight of the material and its internal friction angle should be determined by consulta- tion with the soils engineer. We = total dead load of earth at top of conduit, N/m pbf/ft) Cd = trench coefficient, dimensionless Bd = trench width at top of conduit < 1.5 6c, m (ft) Be = outside diameter of conduit, in (ft) H = variable height of fill, in (ft). When He 2 2Bd, H = Hh. When He < 2Bd, H varies over the height of the conduit. p' = soil constant, dimensionless Values for Kp' and Cd can be taken from Figure 2-5. (b) When the height of the fill above the top of the conduit (Hc) is less than twice the trench width, the hori- zontal pressure should be assumed to vary over the height of the conduit. When He is equal to or greater than 28d• the horizontal pressure may be computed at the center of the conduit using an average value of H equal to Hh 2-6 (d) Where submergence and water surcharge are applicable, the loadings must be modified. To obtain the total vertical load, the weight of the projected volume of water above the conduit, including any surcharge water above the fill surface, is added to the larger value of We obtained by using the submerged weight of the material used in Equations 2-5 and 2-6. The horizontal pressure is obtained by adding the full hydrostatic pressure to the pressure found by Equation 2-8 using the submerged weight of material. (2) Trench with superimposed fill (Condition II). (a) This loading condition applies to conduits that are completely buried in a trench with a superimposed fill H� above the top of the trench. The trench width and side slopes have the same limitations as specified for the trench condition. The vertical and horizontal unit loads for this loading condition vary between the computed val- ues for the Conditions I and III (trench and embankment conditions) in proportion to the ratio HI(Hc + Hp). The vertical load, in N/m (pounds per foot) of conduit length, for the Condition II (trench with superimposed fill) should be computed as the larger of the two values obtained from Equations 2-9 and 2-10. EM 1110-2-2902 31 Oct 97 15 c — o_ o 14 13 12 11 10 MENNEN MENEM 9MOMMEMS 0 8NONE ..on SOMEHOW W 7 MENEM J s MEMORIES MEMNON 5 No ONE NJ 0 3 2 1 MEN No EMEMOMMEMIN NONE 0 0 1 2 3 4 5 VALUES OF COEFFICIENT—Cd Load per unit of length. We •C ryba [M,KN2(ft. lb.)] u - the 'coefficient of internal friction' ry- unfit weight of fill materials. in the fill materials, abstract number. 'coefficient u'- the of sliding friction' 9bbreadth of ditch of top of structure between tt,- fill materials and the C = height of fill over top of structure sides of the ditch, abstract number. / - u K= ;/u Figure 2-5. Earth loads trench condition 2-7 EM 1110-2-2902 31 Oct 97 or We = Cdybd2 + ( - H HfHp I(1.5 ybcHn - CdYbd2 ) We = YbcHh + Hf l (_j7' + yp I(1.5 ybcHh - Yb Hh ) where y = unit weight of fill, N/m3 (pef) bd = trench width, in (ft), bd <_ = 1.5 be (c) For loading cases with submergence and water surcharge, the horizontal and vertical earth pressures should be similarly proportioned between the results (2-9) obtained for Conditions I and III (trench and embankment conditions) with surcharge added to the hydrostatic pressure. (2-10) Hf = height of superimposed fill above the top of the trench, in (ft) He = height of fill above top of conduit, in (ft) Hp = height of conduit above level adjacent foundation, in (ft) be = outside dimension of conduit, in (ft) Hh = height of fill above horizontal diameter of con- duit, in (ft) (b) For low fills it may be desirable to use an effec- tive height slightly less than Hh. The horizontal pressure for Condition II loading is determined using Equation 2-11. Pe = YH [ant � H (45' - /+ f 2 J H°+ Hp (2 11) �0.5 yH - yH tang (45 t 2 where H = variable height of fill above conduit, in (ft) (see definition, paragraph 24d(I)(a)) 2-8 (3) Embankments (Condition III). (a) Condition III applies to conduits and culverts that project above an embankment subgrade and to conduits and culverts in ditches that do not satisfy the requirements of Condition I or II. For this condition, the design should cover a range of possible loading conditions from the initial condition to the long-time condition by satisfying two extreme cases: Case 1, with p1We = 0.33 (We = 150 percent vertical projected weight of fill material, lateral earth pressure coefficient k = 0.50); and Case 2, p1We = 1.00 (We = 100 percent vertical projected weight of fill material, k = 1.00). The total vertical load in N/m (lbf/ft) for this condition should be computed as shown in Equations 2-12 and 2-13: For Case I, We = 1.5 ybA (2-12) For Case 2, We = yb Hh (2-13) or the unit vertical load N/m2 (psf), We, as given by Equations 2-14 and 2-15: For Case 1, We = 1.5 y Hh (2-14) For Case 2, We = y Hh (2-15) The horizontal loading N/m2 (psf) should be taken as shown in Equations 2-16 and 2-17: For Case 1, pe = 0.5 y H (2-16) For Case 2, pe = y H (2-17) Normal allowable working stresses should apply for both Case l and Case 2. (b) Where submergence and water surcharge are applicable, their effects must be considered as for Condi- tion 1. In such cases, the vertical load as computed by Equations 2-12 through 2-17, using the submerged weight of the material should be increased by the weight of the projected volume of water above the conduit including any surcharge water above the fill surface. When a clay blanket is applied to the face of the dam, the weight of water above the blanket must be included but the soil weight below the blanket and above the phreatic line (or the line of saturation where capillarity exists) is that for the natural drained condition. The horizontal unit pres- sure is found by adding full hydrostatic pressure to the value of p, obtained from Equation 2-16 or 2-17 using the submerged weight of the material. 2-5. Special Conditions a. General. If conditions are. encountered that war- rant deviation from the loading criteria discussed above, justification for the change should be submitted with the analysis of design. However, the designer must first select the most economical method of installation. Where the rock surface occurs above the elevation of the bottom of the conduit, the designer should investigate the relative costs of excavating away from the conduit and backfilling between the conduit and the excavation line, allowing sufficient space between the conduit and the excavation line for operation of compaction rollers, and placing the conduit directly against rock as indicated for the following conditions. b. Walls cast against rock. Where the conduit walls are placed directly against rock and the rock surface is at or above the top of the crown, the soil weight should be taken as 1.0 times the weight of material above, rather than 1.5, and the lateral pressure should be hydrostatic only, where applicable. Where the rock surface is at an intermediate level between crown and invert, use judg- ment to select a value between 1.0 and 1.5 to multiply by the weight of material above to obtain the correct soil design load. Lateral soil pressure should be applied only above the rock level and hydrostatic pressure as applica- ble over the full height of conduit. For either of these cases, the condition with no hydrostatic pressure should also be considered. 2-6. Methods of Analysis Cast -in -place conduits can be designed using simplified elastic analysis or with finite element codes. Specialized finite element codes are available that feature nonlinear soil elements. These specialized codes provide the most accurate analysis. If these codes are not available, general finite element codes can be used, but they may need to be calibrated to the actual soil conditions. The finite element approach lends itself to parametric studies for rapid analysis of various foundation, bedding, and compaction conditions. Consult a geotechnical engineer for determi- nation of soil spring constants to be used in the finite EM 1110-2-2902 31 Oct 97 element model. Both concrete thickness and reinforcing steel area should be varied to obtain the best overall economy. a. Finite element analysis. Finite element analysis is a useful method to design sections with unique shape for various field stresses. This method can be used to approximate the soil -structure interaction using spring foundations and friction between elements. These models calculate flexure and shear loads on the design section directly from soil -structure interaction relationships. The design of reinforcement for flexure and shear should be in accordance with EM 1110-2-2104. When the inside face steel is in tension, the area of steel needs to be limited to reduce the effects of radial tension. Therefore, limits on the amount of inside face steel that can be developed are necessary to prevent interior face concrete spalis or "slab- bing failures." If more steel is required to develop the flexural capacity of the section, use radial ties. They should be designed in accordance with American Concrete Institute (ACI) 318 for shear reinforcement. b. Curvilinear conduits and culverts (CURCON). This Computer -Aided Structural Engineering (CASE) program performs a structural analysis for conduit shapes including horseshoe, arch, modified oblong, and oblong sections with constant thickness, base fillets, or a square base. Loads that can be analyzed include groundwater and surcharge water in embankment backfills. 2-7. Reinforcement a Minimum longitudinal. Longitudinal reinforce- ment should be placed in both faces of the conduit as shown in Figure 2-6. The minimum required area of reinforcement should not be less than 0.0028 times the gross area of concrete, half in each face, with a maximum of #30M at 300 min (#9 at 12 in.) in each face. Gener- ally, the same reinforcement will be in each face. Maximum spacing of bars should not exceed 450 min (18 in). b. Minimum transverse. Minimum transverse rein- forcement should be placed in both inside and outside faces. Minimum required area of transverse steel, even when not carrying computed stresses, should not be less than 0.002 times the nominal area of concrete in each face, but not more than #25M at 300 mm (#8 at 12 in.) in each face, unless required to carry the computed stresses. Compression reinforcement in excess of this minimum should not be used. 2-9 EM 1110-2-2902 31 Oct 97 LS Gate 4 of Dom Structure UPSTREAM I DOWNSTREAM Dumped Rack I Selected "foRandom Material e materrialial RomMaterial Stilling 80s1n Mat For monolith lengths see paragraph 2-8 of text _ Olscharge Channel �-Relnforced concrete RESERVOIR OUTLET WORKS —LONGITUDINAL SECTION THROUGH CONDUIT ON ROCK Notes: I. Conduit strength should vary roughly in accordance with helgtt of overburden or otter loading conditions so the overall structure will have essentially a constant safety factor throughout its lenghh. Prefabricated conduit can usually be varied for strength class commercially available. For cost-ln-place conduit both concrete thickness and reinforcing steel area should be varied to obtain the best overall 2�The Corps EM 1110-2-2102 Waterstops and otter Joint Motertate. Illustrates various slopes of rubber and polyvinylchlorlde commercially available. " oo Minimum area Flexible waterstop $ 3� longitudinal steel `p� (see note 2) TOO. i I Constructon Symm. c join," about nt , IZ �� i saTroM QI Monolith 100mm W) 100mm (4') 2 joint clear, p clear. typ Top form inner surface Whabove point of (1.75: I) slope ere severe ero.slon Is anticipated the protective covering should gradually Increase to about 150mm (6') at the Inert OBLONG MODIFIED CIRCULAR DETAIL SHOWING SECTION SECTION CONTRACTION JOINTS Figure 2-6. Typical conduit details (large dams) 2-10 EM 1110-2-2902 31 Oct 97 c. Minimum cover. Minimum concrete cover of reinforcement should not be less than 100 mm (4 in.). 2.8. Joints a. Transverse monolith joints. Maximum contrac- tion joint spacing should not exceed 6 m (20 ft) on earth foundations and 9 m (30 ft) on rock, as shown in Fig- ure 2-6. When large settlements are expected, these max- imum spacings should be reduced to allow for more movement in the joint. A geotechnical engineer should be consulted for soil settlements. b. Longitudinal construction joints. The position of the longitudinal construction joints indicated in Figure 2-6 can be varied to suit the construction methods used. When circular and oblong conduits are used, the concrete in the invert section should be top -formed above the point where the tangent to the invert is steeper than 1 vertical on 1.75 horizontal. 2-9. Waterstops Flexible -type waterstops should be used in all transverse contraction joints, as shown in Figure 2-6. Guidance on the selection of waterstop materials is given in EM 1110-2-2102. Where large differential movement is expected, a center -bulb -type waterstop and a joint separa- tion of approximately 13 mm (1/2 in.) should be used. When the conduit rests on a rather firm foundation, a two -bulb or equivalent type waterstop should be used with a joint separation of approximately 6 mm (114 in.). For conduit on rock foundations with little expected deforma- tion, the joint should be coated with two coats of mastic and an appropriate waterstop should be used. 2-10. Camber When conduits are cast -in -place, large settlements are usually not a major concern. However, where consider- able foundation settlements are likely to occur, camber should be employed to ensure positive drainage. 2-11 Chapter 3 Circular Reinforced Concrete Pipe for Small Dams and Levees 3-1. General Reinforced concrete pipe should be used for small dams, urban levees, and other levees where loss of life or substantial property damage could occur. Reinforced concrete pipe may also be used for less critical levees. Ancillary structures such as inlet structures, intake towers, gate wells, and outlet structures should be constructed with cast -in -place reinforced concrete. However, precast concrete may be used for less critical levees when designed and detailed to satisfy all loading and functional requirements. 3-2. Materials: Small Dams a. Overview. Reinforced concrete pipe discussed in this chapter is designed by either the direct or indirect (D-load) method. This approach indirectly compares the moments and shears for the pipe section to a standard three -edge bearing test. The minimum diameter pipe used should be 1,220 mm (48 in.) to facilitate installation, maintenance, and inspection. 6. Reinforced concrete pipe through dams. Pipe through small dams should be concrete pressure pipe, steel cylinder type. Pipe joints should be deep or extra deep with steel joint rings and solid 0-ring gaskets, and they should be used for the entire length of pipe between the intake structure and the stilling basin. The steel cylin- der provides longitudinal reinforcement and bridges the gap if transverse cracks develop in the concrete. Steel joint rings can be readily attached to the steel cylinder. Reinforced concrete pipe with either steel end rings or a concrete bell -and -spigot joint can be used in less critical areas. Joints should have solid D-ring gaskets, and the pipe may or may not be prestressed. Also, a steel cylin- der is optional. All acceptable pipe must be hydrostatic tested. (1) Steel cylinder. When the steel cylinder is used, the cylinder should have a minimum thickness of 1.5 mm (0.0598 in.) and 25 mm (l in.) minimum concrete cover. (2) Prestress wire. When prestressing is used, the wire should have a minimum diameter of 5 mm (0.192 in). E M 1110-2-2902 31 Oct 97 (3) Mortar covering. The minimum concrete cover over prestressing wire should be 19 mm (3/4 in.). (4) Concrete cover. The minimum concrete cover over plain reinforcing bars or welded wire fabric should be 38 mm (1.5 in). (5) Cement. Cement used for concrete, grout, or mortar shall be type 11. (6) Steel skirts. These skirts are used on prestressed noncylinder concrete pipe to hold the steel ring in place. Skirts shall be welded to steel joint rings for noncylinder pipe, and longitudinal reinforcement shall be welded to the steel skirt for anchorage. (7) Reinforced concrete pressure pipe, steel cylinder type. Design in accordance with American Water Works Association (AWWA) C 300. This pipe is designed by the direct method in accordance with AWWA C304. (8) Prestressed concrete pressure pipe, steel cylinder type. Design pressure pipe in accordance with AWWA C 301. This pipe is designed by the direct method in accordance with AWWA C 304. (9) Reinforced concrete pressure pipe. Design in accordance with AWWA C 302 or ASTM C 76. This pipe is designed by the indirect method (D-load). 3-3. Installation: Small Dams Bedding conditions are illustrated for trenches in Fig- ure 3-1 and for embankments in Figure 3-2. When pre- cast concrete pipe is used for small dams, this pipe connects the intake structure to the stilling basin. The typical installation of this pipe is shown in Figure 3-3, which shows where to use two half lengths of pipe at connection to structures and the use of the concrete cra- dle. Deep or extra deep joints are of particular impor- tance through the selected impervious material on the dam since this area is likely to experience the most settlement. a. Reinforced concrete pipe. Reinforced concrete pipe through the select impervious material of the dam embankment should conform to either AWWA C 300 or AWWA C 301 between the intake structure and the still- ing basin and maybe to AWWA C 302 in less critical areas of the dam, as shown in Figure 3-3. 3-1 EM 1110-2-2902 31 Oct 97 Backfilled uMamped O Rack Q Faundatlan not1 formed to flt IMPERMISSIBLE PIPE LAYING METHODS FOR TRENCHES Farmed Foundation 05 be tNn ORDINARY PIPE ............... (8'J rNn. OAI 4 (1 per ftIJ of Ne when Hey 171M (l6 ftJ LAYING METHODS FOR TRENCHES Earth booth/!, carefully placed and hand tamped In layers nN exceedlrq /50mm 10 -----7 300mm (129 min. Sand _ Formed CusNon Foundation /, p�f�� 06 [� min H� (4800mmim; e FIRST CLASS PIPE LAYING METHODS FOR TRENCHES He • depth of f111 over top of pipe Figure 3-1. Trench bedding conditions b. Cement -mortar grout. When concrete pipe is used, the exterior joint space should be grout -filled after pipe installation and hydrostatic tested, and the interior joint space should be grout- and mortar -filled after pipe installation, hydrostatic testing, and backfilling are completed. c. Fittings and special pipe. These sections are used when there are alignment changes or connections to dif- 3-2 ferent sizes or types of pipe. The fittings and specials used should be designed for the same loading conditions as the regular pipe. Long -radius curves and small angular changes in pipe alignment should be made by deflecting the pipe at the joints or by using straight pipe with beveled ends, beveled adapters, or a combination of these methods. Beveling one end of straight pipe is often more economical than beveling both ends, and a combination of EM 1110-2-2902 31 Oct 97 Embankment Rock Shallow Earth O Forth O Cush'on Foundation not formed to fit (a) IMPERMISSIBLE BEDDING Embankment b + 100mm (4-) minimum (Earth fill) Mtn. -b. Rock Earth b l0 8 Earth � Formed 0.04 � f p� ftd Cus/Yon Foundation of IM (8 /nJ min. (b) ORDINARY BEDDING Embankment 15MP0 Earth fill) (2000 psi) concrete Earth max. p-OJ *pbc or better - Mtn. -b 4y/0tamped Thour h/Min. earth Mln. - %4Formeln. -� Inside Foundation /0 diameter (c) FIRST CLASS BEDDING (d) CONCRETE CRADLE BEDDING Hc - depth of fill over top of pipe p - projectlon ratio : ratio of the vertical distance between the top of the conduit and the natural ground surface adjacent to the conduit, to bc Figure 3.2. Embankment bedding conditions 3-3 EM 1110-2-2902 31 Oct 97 Gone x of Small Dom Drainage Fill (see EMIIIO-2-1913 and Structure UPSTREAM DOWNSTREAM EMI110-2-2300 for more details) pact .v� N DOT P� Selected Sluice Random Wier lot lmpervlWs Random Material Gate Material Stilling Basin LL 1 rkw L L 3 i L L L L L L L L L L L I L L I L L L f 7L Dlsctarge Ctannal LTJ LPressure Pipe `Concrete Cradle Bedding l as required Reinforced Concrete PIX Pressure Pipe from toe to Reinforced Concrete From Inlet structure to toe toe of embankment Pipe from toe of of ime embankment embankment to stilling basin Figure 3-3. Reservoir outlet works (small dams) straight and beveled pipe can be economical. Again, steel end rings should be used for fittings and specials. d. Pipe laying lengths. Lengths of pipe used should not exceed 4.9 m (16 ft) for conduits when minimal foun- dation settlements are expected, and pipe lengths of 2.4 to 3.7 m (8 to 12 ft) should be used when nominal settle- ments are expected. Two half lengths of pipe should be used immediately upstream of the intake structure, imme- diately downstream of the intake structure, at the end of the concrete cradle, immediately upstream of the stilling basin, and when there is a change in the foundation stiffness. e. Concrete cradle. Concrete cradles should be used to carry the conduit through soft foundation mater- ials. The cradle is used between the intake structure and the point downstream where it is no longer required by the design, but not less than the toe of the major embank- ment section. Cradles are to be used for the fast pipe length upstream of the intake structure and the stilling basin and under horizontal curves. Cradles should be terminated at the end of a pipe length. Disturbed founda- tion material should be backfilled to grade with lean con- crete. Recompacting the foundation is not allowed. f. Cradle reinforcement. Cradles should be continu- ously reinforced in the longitudinal direction with temper- ature and shrinkage reinforcement. The minimum amount of reinforcing steel in both directions should not be less than 0.002 times the gross area of the concrete. The 3-4 transverse area of concrete is based on the concrete thick- ness below the pipe invert. g. Dowels across joints. Joint dowels should be adequate to transfer the shear capacity of the cradle or the maximum differential load anticipated when an excess cradle capacity is provided. A compressible material with a minimum thickness of 13 mm (1/2 in.) should be used in the joint to accommodate slight foundation deflections. h. Field testing joints. Joints for pipe through dams should be field-tested using a hydrostatic test after pipe is installed and prior to placement of the concrete cradle, the grouting or mortaring of joints, and the back - filling of the trench above the bedding. Hydrostatic testing should be 120 percent of the maximum design pressure for the pipe and in accordance with AWWA standard. An acceptable joint tester may be used for this testing requirement. Joints that fail the test should be replaced and retested until they are acceptable. Additional joint testing may be completed after backfilling, when watertightness is questioned. 3-4. Materials: Levees Reinforced concrete pipe used in levees should meet the requirements of AWWA C 302 or ASTM C 76 as a mini- mum. The minimum diameter pipe for major levees should be 1,220 mm (48 in.) to facilitate installation, maintenance, and inspection. Other levees may have a minimum diameter of 910 rum (36 in.). 3-5. Installation: Levees Pipes crossing under levees typically have a landside inlet structure, gate structure, and a floor stand. Figure 3-4 shows several possible variations for levee drainage struc- tures. Two half lengths of pipe should be used at each structure connection to provide flexibility, as shown in Figure 3-5. Note that a granular drainage blanket is placed on the landside end third of the pipe. a. Pipe laying lengths. Laying lengths should not exceed 3.7 m (12 ft) for conduits with normal foundation settlements, and these lengths should be reduced to 2.4 in (8 ft) when excessive settlements are expected. Two half lengths of pipe should be used at the upstream and down- stream ends of the gate well structure, and when the foun- dation stiffness changes. When steel end rings are not used, a short concrete pipe should be laid through the wall of the gate well or intake structure, and the wall should be cast around the pipe as shown on the drawings. The mating end of the pipe should extend no more than 300 mm (12 in.) beyond the edge of the gate well struc- ture, and the embedded end should have an appropriate waterstop. b. Concrete cradle. Concrete cradles should be provided under the first length of pipe at the upstream and EM 1110-2-2902 31 Oct 97 downstream ends of gate well structures. They should be doweled into the gate well slab to carry the full shear capacity of the cradle. The joint should be filled with a compressible material and have a minimum thickness of 13 mm (I/2 in.). C. Field testing pipe joints. Joints for pipe through levees should be field-tested for watertightness using a hydrostatic test after pipe is installed, and prior to the grouting or mortaring of joints and the backfilling of the trench above the bedding. Hydrostatic testing should be in accordance with the appropriate AWWA standard. An acceptable joint tester may be used for this testing requirement. Joints that fail the test should be replaced and retested until they are acceptable. Additional joint testing may be completed after backftlling, when water- tightness is questioned. d. Gate wells. Gate wells should be cast -in -place concrete for major levees. Precast concrete gate wells may be used for less critical levees if designed and detailed to satisfy all loading and functional requirements. The loading requirements must include the maximum loads that can be applied through the gate lifting and closing mechanism. These mechanisms are usually designed with a factor of safety of five. This will usually LANDSIDE Q of Levee RIVERSIDE OroMoge Fill 3 100 � t °� Natural ground ,g Flop gate Channel Gnnom 4? . Flared a rele Reinforced Reinforced concrete end sectlon °oncrele pipe cutlet structure Rlprop I Flrxv Stand Drainage Fill Rlprap /% Slulce I I gore Outlet structure Rlprop e nforced concrete p'pe Floor Stony Gatewell Existing Drainage Fill y Dlsc/nrge pipes from pumping ground plants may terminate In gatewells surface RWap I Outlet structure Riprop I Sluice gale Inlet structure for - Reinlorced Flap gate required concrete p1pe concrete pipe for fosf-rlsitg streams TYPICAL SECTIONS — DRAINAGE STRUCTURES THROUGH LEVEES Figure 34. Typical sections, drainage structures through levees 3.5 EM 1110-2-2902 Change 1 31 Mar 98 IS or Levee LANDSIDE Floor Stall RNERSIDE Existing Ground Surface j Riprop LS/ Sluice Gate Outlet Structure Drainage blanket or Pile Bent Fkw z z .C.. .L L L L L L i I z I L I L I L I L I L I zl H L IL L—I- L--,I Inlet Structure for pipe Reinforced precast LConcrete Cradle as needed concrete Figure 3-5. Typical precast conduit (levees) require mechanical connections between pipe segments and additional longitudinal reinforcement in the pipe. The top, bottom, and gate frame must be securely anchored to resist all loading conditions. The joints for the gate well should be the same type as used for the pipe conduit. The installed gate well should be subjected to a hydro- static test prior to backfilling. e. Inlet structures. Inlet structures should be cast - in -place concrete in major levees, but may be precast as appropriate. f. Outlet structures. Outlet structures are normally cast -in -place concrete, U-wall-type structures. Pile bents may also be used. g. Pile bents. When pile bents are used to support a length of pipe, pipe lengths should be limited to 4.9 m (16 ft). Two pile bents, as shown in Figure 3-6, are required for each pipe section when using 2.4-m (8-ft) lengths of pipe, and three pile bents are required when pipe lengths are 4.9 m (16 ft). The two upstream sections of pipe beyond the pile bent should be two half lengths of pipe to develop joint flexibility. Mechanical connectors should be used on pipe joints when the pipe is supported on pile bents. 3-6. Loadings 3-7. Methods of Analysis a. D-load analysis. This analysis and the selection of pipe should be based on a Door crack using the approach in Section 17.4 of American Association of State Highway and Transportation Officials (AASHTO) (1996) with the following exceptions. (1) Standard trench and embankment installations are presented in Figures 3-1 through 3-4, and paragraphs 3-3 and 3-5. The bedding factors BI to be used for these installations are listed in Table 3-1. Bedding factors for the embankment conditions are shown in Table 3-2 and calculated using Equation 3-1: B _ 1.431 i X - (Xa13) (3-I) P (2) For these installations the earth load, We should be determined according to the procedure in paragraph 2-4 for Condition I only, except li is equal to H�,. (3) For these installations, the design load deter- mined by AASHTO Equation 17-2 (AASHTO 1996) must be increased by a hydraulic factor Hf of 1.3, as shown in Equation 3-2, the modified AASHTO Door crack design equation: The loadings used for precast concrete pipe are the same Do01 _ (HjWr)1(SBf) (3-2) as those described in Chapter 2 for cast -in -place concrete pipe. 3-6 LIZ (mini L12 L/2 I I 600 mm (2'-0') (TypJ Plpe support Pipe II II L II III L II II LI II II II II II II II II LI LI LI LI PROFILE Treated bridge NOT TO SCALE beams (t x wl, typ. 600 mm (241 (Typi Treated timber piling (d), typ. Automatic f RCP- flop gate ----- — 150mm (6'1 ASTU A307 galvanized bolts. rutr Existing and wasters typicalgroundNotch posts beams, typicaZE E8 a SIDE ELEVATION PIPE SUPPORT DETAILS NOT TO SCALE AUTOMATIC FLAP GATE NOT TO SCALE Figure 3-6. Typical pile bent EM 1110-2-2902 31 Oct 97 coupler AVAutomatic flap gale aL Existing II ground II U to to E E E I � 150mm Q� _ (6') 50mm END VIEW Grouted anchors as required by flop gale manufacturer to fasten flap gate to reinforced concrete pipe 3-7 EM 1110-2-2902 31 Oct 97 Table 3-1 Design Conditions: Trench Type of Bedding Bedding Factor Br Ordinary 1.5 First Class 1.9 Concrete Cradle 2.5 Table 3-2 Bedding Factor Constants: Embankment Projection Ratio P Concrete Bedding Xa Other Projection Bedding Xa 0 0.15 0 0.3 0.743 0.217 0.5 0.856 0.423 0.7 0.811 0.594 0.9 0.678 0.655 1.0 0.638 0.638 Type of Bedding Xe Ordinary 0.840 First Class 0.707 Concrete Cradle 0.505 where WT=WB+WF+WL and Hf = hydraulic factor of 1.3 Si = internal diameter or horizontal span of the pipe in mm (feet) Bf = bedding factor. See Table 3-1 for trench condition and use Equation 3-1 with Table 3-2 for embankment condition WE = earth load on the pipe as determined according to the procedures outlined in Chapter 2, using case 1 only except replacement of H with H. WF = fluid load in the pipe WL, = live load on the pipe as determined according to paragraph 54 3-8 b. Multiple pipes. When several pipes need to be installed in the same trench, the designer must determine the loading condition to use. Two common installation conditions are shown in Figures 3-7 and 3-8. The soil columns used for this loading analysis are identified in these figures. The design method described below pro- vides conservative results. Figure 3-7. Multiple pipes In trench Figure 3-8. Benched pipes (1) Trench condition. Load for multiple pipes varies from a simple trench condition to a projected embankment condition, or even a combination of both within the same trench. Each pipe should be analyzed separately, and the transition width should be determined for each pipe. The transition width is the width of a trench when the trench load is equal to the projected embankment load. There- fore, trench loads cannot be greater than the projected embankment condition. The geometric relationship for three pipes in a trench is shown in Figure 3-7. If Bch (the outside diameter of the center pipe) plus 2Y (twice the width of the soil column between the pipes in the trench) is equal to or greater than the transition width for the given size pipe, then pipe C is designed for a positive projected embankment condition. If the intermediate pipe spacing Y and the exterior pipe spacing to the trench wall Z are small compared to the outside diameter BC and the height of fill H, then the entire earth load may be shared proportionately by the three pipes, and the entire installa- tion is in a trench condition. Also, when the exterior pipe columns Bdy/2 or BdB2 are less than one-half of the transition width for either pipe (about 0.75 Br), then the trench condition exists. However, the positive projected embankment condition exists when the width of these exterior pipe columns is greater than the transition width for the pipe. The interior columns are analyzed in a similar manner. (2) Bench condition. When vertical and horizontal separation distances must be met, a common method of installing multiple pipes in the same trench is placing the pipe in a bench condition, as shown in Figure 3-8. When used, the stability of the bench needs to be analyzed, and load transfer between pipe "A" to pipe "B" is ignored. Two methods that may be used to install pipe in this condition are to excavate the full depth and full width of the trench, then backftll to the appropriate bench height before installing the second pipe; and to excavate a full - width trench to the top of the bench and then excavate the side trench. Once again, the geometry of the trench deter- mines the loading condition on the pipe. When the soil columns Bd4 and BdB are less than the transition width for the pipe, the trench load is used. When these soil col- umns are greater than the transition width, the positive projecting embankment load is used. Normally, the trench will be excavated the full width to install pipe "B" then backfilled to the "CD" level, and pipe "A" is installed. This would place pipe "B" in a positive project- ing embankment condition, and then pipe "A" must be analyzed for the transition width above the pipe crown. 3-8. Joints a. In pipe. Joints for precast concrete pipe must resist the infiltration/exfiltration leakage, accommodate EM 1110-2-2902 31 Oct 97 lateral and longitudinal movements, provide hydraulic continuity, and allow the pipe to be installed easily. Each precast manufacturer makes a pipe joint that conforms to one or more ASTM test requirements. Pipe with an inte- gral 0-ring gasketed joint should be used on pipe through small dams and levees. Mortar and mastic packing are not acceptable. The two types of joints specified by ASTM criteria, depending on the working pressure of the pipe, are ASTM C 443 and ASTM C 361. Working pres- sure rating for an ASTM C 443 pipe is 90 kPa (13 psi) in straight alignments and 70 kPa (10 psi) in axially deflected alignments. The working pressure rating for an ASTM C 361 pipe joint is up to 45.7 m (150 ft) of head. lkhen specifying joints on precast concrete pipe through small dams or levees, pipe must have an integral 0-ring gasket and pass the pressure test before the installed pipe can be accepted. Deep and extra deep joints should be specified for pipe in small dams and large levees where excess deflections are expected. b. At structures. Integral 0-ring gaskets and steel end rings are required at gate wells and gated outlet struc- tures on small dams and major levees. C. Testing. Pipe joints may be tested using an internal pressure. (1) Factory. Three ASTM tests are used to assure the pipe's integrity. First joints and gaskets shall be 0-ring type in accordance with ASTM C 361. When pipe is D-load rated the strength capacity of the pipe will be determined by testing in accordance with ASTM C 497. Performance requirements for hydrostatic testing of pipe shall conform to ASTM C 443. (2) Field testing with joint tester. All joints under embankments should be tested for leakage. Tests should include hydrostatic pressure tests on all concrete pipe joints under levees to be performed by the contractor after the pipe has been bedded and prior to placing any back - fill. Testing of joints should be made by using a joint tester. Joints are required to withstand an internal pres- sure equal to the working pressure plus transient pressures for a duration of 20 minutes per joint. After backfilling the pipe, the contractor should perform additional hydro- static tests on joints which by inspection do not appear to be watertight. Joints that fail should be disassembled and all inferior elements replaced. The possibility that some water may be absorbed by the concrete pipe during this test should be considered before rejecting the rubber seals proposed. 3-9 EM 1110-2-2902 31 Oct 97 (3) Water -filled pipe test. Where practical, pipe joints can be tested for watertightness in the field by using the water -filled pipe test. The pipe should be free of air during this test and be maintained at the test pressure for a minimum of 1 hour. The possibility that some water may be absorbed by the concrete pipes during this test should be considered before rejection of the rub- ber seals proposed. Water should be added as necessary to maintain a completely full pipe at the specified head. On outlet works pipe, testing can be in increments as installed or for the full length after installation is completed. 3-9. Camber Where considerable foundation settlement is likely to occur, camber should be employed to assure positive drainage and to accommodate the extension of the pipe due to settlement, as shown in Figure 3-9 (EM 1110-2- 1913). 3-10 f i FBI-\ Comnerm CanduN comae Fl/bl grade affu sef lMW canner allays far seH/enww of a cuMevf under a IYpn IN. Ma of the fall Is In Ile "Id W. 010"Wers 3000M I10 fli and smo wore ws/er to canner, as are the Ilgffer wall fflctnesses. Figure 3-9. Cambered conduit Chapter 4 Corrugated Metal Pipe for Rural Levees and Culverts 4-1. General Corrugated metal pipe may be used in rural levee systems when risk of substantial property damage and loss of life is low. Corrugated metal pipe is subject to chemical and galvanic corrosion, is not easily tapped, has a high hydraulic coefficient of friction, and is vulnerable to joint leakage and associated piping and to live load distortion. When this pipe is used, a life cycle cost analysis should be performed. The service life of a flood control project is 100 years, and corrugated metal pipe systems must be designed to meet this requirement. Typically, corrugated metal pipe may have to be replaced a minimum of once during this project life. Use 900-mm- (36-in.-) diameter pipe as a minimum for levees to facilitate installation, maintenance, and inspection. a. Corrugated metal pipe. This pipe may be used as an option in agricultural levees where the levee embank- ment is less than 3.7 m (12 ft) above the pipe invert. Circular pipe must be used through levee embankments. b. Corrosion protection. Corrugated metal pipe is susceptible to corrosion, primarily in the invert. The pipe should always be galvanized and protected with a bitumi- nous coating and should have bituminous paving applied to the invert. Bituminous coatings and paving can add about 20 to 25 years of service life to the pipe, and a bituminous coating (AASHTO M 190) alone adds about 8 years of service life to the pipe. Polymer coatings (AASHTO M 246) can add about 10 years of service life to the pipe. If the fill or backfill materials contain chemically active elements, it may be necessary to protect the outside of the pipe with a coating of coal tar epoxy. The life of galva- nized conduits can be estimated by using information from the American Iron and Steel Institute's (AISI) Handbook of Steel Drainage and Highway Construction Prod- ucts (1993). When considering other coatings, the designer should review applicable test data for similar installations. (1) Metallic -coated corrugated steel pipe. Metallic - coated corrugated steel pipe should conform to American Association of State Highway and Transportation Officials (AASHTO) M 36, M 218, M 246, and M 274. When spiral rib steel pipe is used, the material should conform to AASHTO M 36 and M 245. When bituminous coatings are EM 1110-2-2902 Change 1 31 Mar 98 required, the material should conform to AASHTO M 190. For installations involving only fresh water, the Type C coating should be used except when the pH value of the soil or the water at the installation site is below 5 or above 9. In this case, the coating should be ASTM A 885, Aramid Fiber Composite, and AASHTO M 190. For all seawater installations, the coating should be ASTM A 885 and AASHTO M 190. Both the loading conditions and the corrosion characteristics (soil and water) at the installation site should be considered when specifying metal thickness (steel). Metal thickness should be selected to meet the corrosion condition and should not allow the pipe to perforate during the life of the project. The soil resistivity and pH can be determined by a geotechnical engineer. This type of pipe should not be used to conduct strong industrial wastes or raw sewage. In general the environmental conditions for corrugated metal pipe require pH limits of 6 to 8 for galvanized steel, and 5 to 9 for aluminized steel. Soil resistivity should be greater than or equal to 2,500 ohm -cm for galvanized steel and 1,500 ohm -cm for aluminized steel. Long-term field test data suggest that aluminum alloy coatings (Aluminized Type 2, AASHTO M 274) lasts longer than plain galvanized coatings (Zinc, AASHTO M 218). Before selecting aluminized coatings, the designer should verify local experience with such pipe, and these coatings should not be used for sanitary or industrial sewage, salt water or when heavy metals are present. (2) Corrugated aluminum alloy culvert pipe. This pipe is generally used for culverts and underdrain systems, and should conform to ASTM B 745M. When spiral rib pipe is used, the materials should conform to ASTM B 745M and should be included in the specifications for culverts, storm drains, and other applications on relocations and similar works which will be used on Civil Works Projects or turned over to others. Engineering standards and requirements of the affected authority should be followed. Corrugated aluminum alloy pipe should not be used through dams, levees, or other water retention embankments. (3) Perforation life. Corrugated metal pipe should be designed by the method and equations given in the Hand- book of Steel Drainage and Highway Construction Prod- ucts, except that Figure 4-1 is to be used to calculate the perforation life of the pipe. This figure is applicable to civil works projects. The AISI approach is applicable to gravity flow systems on nonerodible granular beddings, not on silty and clayey sands which are highly erodible. Most civil works projects around spillways and through levees structures are on silty and clayey sands and under pressure. 4-1 EM 1110-2-2902 31 Oct 97 0 0 0 .._I-._........__..}_._..._........_............................... .__._._}-._._..-O.f Yi.A..atr.._...0........iG_..._._..-.{�..::::::..._.-.. --._..- _ _..._i..--_._.._..t.._....._--. c O i ri .. ..._...i ._.__ i...... ...... ....... .a_ .. ..... . ......._.. .....__._ ! .............. i ----------- -_... _�.__ .._: .__... ...t. .....__.. i.._... .......... 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FL > .E m c E c ...p._._..........._ .....__..... m � a 2 C7 aH F E c c4 s UORW0Nad 01 sJeGA 4-2 a 4-2. Materials Table 4-1 lists the applicable ASTM standards for the materials used in the design of corrugated metal pipe systems. a. Corrugated metal gate wells. Corrugated metal gate wells may be used in lieu of cast -in -place concrete where corrugated metal pipes are permitted, if designed and detailed to satisfy the same requirements as precast gate wells. These gate wells need to be designed and EM 1110-2-2902 Change 1 31 Mar 98 detailed to satisfy the loading and functional requirements. The loading requirements must include the maximum loads that can be applied through the gate lifting and closing mechanism. These mechanisms are usually designed with a factor of safety of five. This will usually require mechanical connections between pipe segments. The top, bottom, and gate frame must be securely anchored to resist all loading conditions. The joints for the gate well should should be the same type as used for the pipe conduit. The installed gate wells should be hydrostatic tested prior to backfilling. Table 4-1 Materials for Corrugated Metal Pipe Systems Materials ASTM Standard Description Polymer -Coated ASTM A 742M - Steel Sheet, Metallic Polymer -coated galvanized sheets or aluminum -zinc alloy Sheets Coated and Polymer Precoated for sheets. Used in environments when metallic -coated pipes Corrugated Steel Pipe cannot be used. Fully Lined Steel ASTM A 760M Type 1A - Corrugated Steel This standard is for corrugated metal pipe being used as Pipe, Metallic -Coated for Sewers and Drains storm -water drainage, underdrains, and culverts. Included in the standard are requirements for rivets, bolts and nuts, lock seam strengths, coupling bands, and gaskets. Sewer and Drainage ASTM A 762M - Corrugated Steel Pipe, This pipe is not intended to be used for sanitary or industrial Polymer Precoated for Sewers and Drains wastes. It is a standard for polymer -coated zinc or aluminum - zinc -alloy -coated sheet steel. Additional polymer coating may be applied after fabrication of the pipe. Included in the stan- dard are requirements for rivets, bolts and nuts, lock seam strengths, coupling bands, and gaskets. Asphalt -Coated or ASTM A 849M - Post -Applied Coatings, Pavings This standard covers the post -applied coatings for steel struc- Paved Invert Steel and Linings for Corrugated ture plate pipe; pipe arches; and arches with paved, lined or Steel Sewer and Drainage Pipe polymer coatings. Coatings include bituminous materials, concrete, mastic, or polymer. Conduits can be fully coated exterior or interior, paved invert, or fully lined. Fiber Bonded Sheets ASTM A 885M - Steel Sheet, Zinc and This is a composite coating of zinc, aramid nonwoven fabric, Aramid Fiber Composite Coated for Corrugated and asphalt coatings used for enhanced corrosion resistance. Steel Sewer, Culvert and Underdrain Pipe Aluminum Sheets ASTM B 744M - Aluminum Alloy Sheet for This standard covers the aluminum sheet used for corrugated Corrugated Aluminum Pipe aluminum pipe that is used for storm -water drains, under - drains, and culverts. Aluminum Alloy Pipe ASTM B 745M - Corrugated Aluminum Pipe for This standard covers the aluminum pipe to be used for storm Sewers and Drains water drains, underdrains, and culverts. Included in the stan- dard are requirements for rivets, bolts and nuts, lock seam strengths, coupling bands, and gaskets. Zinc -Coaled, ASTM A 929M-Steel Sheet, Metallic Coated by This standard includes steel sheet with Zinc-5 % Aluminum - Aluminum -Coated, and the Hot -Dip Process for Corrugated Steel Pipe Mischmelal (Zn-5Al-MM), 55% Aluminum -Zinc Alloy -coated Aluminum -Zinc Coated (55AI-Zn), and Aluminized (Type 1 and 2) coatings. Sheet Steel 4-3 EM 1110-2-2902 31 Oct 97 b. Inlet structures. Corrugated metal inlets may be used where corrugated metal pipes are permitted, if designed and detailed to satisfy the loading and functional requirements. C. Outlet structures. Outlet structures are normally cast -in -place reinforced concrete U-wall structures. d. Pile bents. When pile bents are used to support a length of pipe, pipe lengths should be limited to 4.9 in (16 ft). Two pile bents, as shown in Figure 3-6, are required for each pipe section when using 2.4-m (8-ft) lengths of pipe, and three pile bents are required when pipe lengths are 4.9 in (16 ft). The two upstream sections of pipe beyond the pile bents should be two half lengths of pipe to develop joint flexibility. Corrugated bands should be used on pipe joints when the pipe is supported on pile bents. 43. Installation Corrugated metal pipe for levees and culverts, and struc- tural plate for culverts should be installed in accordance with the requirements set forth in ASTM A 798 for steel pipe or ASTM A 807 for steel plate pipe or ASTM B 788 for aluminum pipe or ASTM B 789 for aluminum plate pipe. a. Foundation. When soft soils or rock are encoun- tered, they should be removed and replaced with approved materials as specified herein. The excavation depth below the pipe invert shall be equal to 42 mm (0.5 in.) per meter (foot) of fill above the crown of the pipe, not to exceed 600 rum (24 in.) maximum. The minimum width of material removed in a trench will be three diameters in soft soil, and one and one-half diameters in rock. b. Backfdl. Structural backfill for pipe in trenches is the material placed around the pipe from invert up to an elevation of 305 mm (12 in.) or one -eighth the diameter, whichever is more, above the pipe. For pipe in embank- ment conditions, structural backfill is the material within one diameter of the sides of the pipe from invert to an elevation of 305 mm (12 in.), or one -eighth the diameter, whichever is more, over the pipe. Acceptable backfill material for corrugated metal pipe includes silty and clayey gravels and sands (SM and SC, Unified Soil Clas- sification System) as approved by the geotechnical engi- neer. Gravels and sands (GW, GP, GM, GC, SW, and SP) are not acceptable backfill materials in levees. Plastic clays and silts, organic soils, and peat are not acceptable materials (OL, MH, CH, OH, and PT). This backfill material is installed in 152- to 305-mm (6-to 12-in.) 4-4 layers compacted per EM 1110-2-1913 and is brought up evenly on both sides of the pipe to a minimum cover of 305 mm (12 in) over the top of the pipe. c. Minimum cover and spacing. (1) Cover. Use the method for calculating the mini- mum cover as defined in ASTM A 796 and ASTM B 790 for steel and aluminum, respectively. However, a mini- mum cover of 610 mm (2 ft) from the top of the pipe to the bottom of the slab or crosstie is recommended for railroads, highways, and airfield pavements. For construction loads, a minimum cover of 1,220 mm (4 ft) is recommended. (2) Spacing. When multiple lines of pipe are installed in the same excavation, a minimum spacing between pipes of one-half the pipe diameter or 900 mm (3 ft), whichever is less, should be used for adequate compaction of the backfill material. These minimum spacings are for compacted backfill and may be less when using slurry or flowable backfills. 4-4. Loadings Earth loads and live loads (highway, railways, runways, and impact) for corrugated metal pipe are defined in ASTM A 796 and ASTM B 790 for steel and aluminum, respectively, as vertical pressures. Horizontal pressures are controlled by backfill requirements. The applications of these pressures are similar to those presented in Figure 5-2. 4-5. Methods of Analysis The design of corrugated steel pipe is covered in ASTM A 796, and the design of corrugated aluminum pipe is covered in ASTM B 790. The designer should consider the design criteria for ring buckling strength, wall crush- ing strength, handling stiffness, and joint integrity. The section properties for corrugated metal pipe and seam strength requirements are provided in ASTM A 796 for steel and ASTM B 790 for aluminum. When corrugated metal pipe is used, an analysis of seam separation should be performed, except when helical lock seam pipe is used. a. Thrust in pipe wall. Thrust in pipe walls must satisfy three criteria: required wall area as determined from ring compression or thrust, critical buckling stress, and required seam strength. (I) Wall thickness. The minimum wall thickness is based on the yield stress of the pipe material, and assumes a factor of safety of 2. This design is defined in ASTM A 796 or ASTM B 790 for steel and aluminum, respectively. (2) Allowable wall stress. The critical buckling wall stress can be determined by using formulas presented in ASTM A 796 and ASTM B 790, for steel and aluminum, respectively. If the critical buckling stress is less than the yield stress of the wall material, recalculate the required wall thickness using the calculated buckling stress. (3) Longitudinal seam stress. Because there are no seams in helical lock seam and welded seam pipe, these criteria do not apply. For pipe fabricated with longitudinal seams (riveted, spot-welded, or bolted), seam strength should be sufficient to develop the thrust in the pipe wall. The factor of safety for longitudinal seams is 3. Also, these joints must be hydrostatically tested for acceptance. Seam strengths for various seam connections are given in ASTM A 796 and B 790 for steel and aluminum pipe, respectively. b. Handling stiffness. The handling stiffness of cor- rugated metal pipe should be checked to ensure that the pipe can be handled without damage during construction. The required flexibility factors for steel and aluminum pipe are given in ASTM A 796 and ASTM B 790, respectively. 4-6. Joints Special attention should be given to the joint between a corrugated metal pipe and any concrete structure. The EM 1110-2-2902 Change 1 31 Mar 98 gaskets and bands discussed below are used to develop leak -resistant joints in corrugated metal pipe. A typical hugger band installation is shown in Figure 4-2, and a typical corrugated band joint is shown in Figure 4-3. Joints through levees must be tested for watertightness, and require the use of corrugated bands. a. Gaskets. For sleeve type gaskets, use ASTM D 1056, Grade 2C2. Sleeve type gaskets should be one- piece construction, closed -cell neoprene, skin on all four sides. The thickness should be 9.53 mm (3/8 in.) and 13 mm (1/2 in.) less than the width of the connection band required. 0-ring gaskets should meet the requirements of ASTM C 361. b. Coupling bands. Corrugated bands and sleeve type gasket are required when watertightness is a concern. For helical pipe, the ends should be reformed so the pipes can be coupled. Flat bands with sleeve or O-ring type gaskets, or hat -channels with mastic bands are not accept- able for watertight joints as they are susceptible to pulling apart. Bands with annular corrugations and rod and lug connectors, semi -corrugated bands and bands with angular corrugations, and angle iron bolt connectors are acceptable connectors. 4-7. Camber Where considerable foundation settlement is likely to occur, camber should be used to ensure positive drainage and to accommodate the extension of the pipe due to settlement. 4-5 EM 1110-2-2902 Change 1 31 Mar 98 Bolt bar and strip Commector Sealant strip CONNECTION DETAIL OF SINGLE HARNESS PROD AND LUG NOT SHOWN) SECTION CONNECTION DETAIL OF ROD AND LUG Figure 4-2. Semi -corrugated band Figure 4-3. Corrugated band 4-6 Chapter 5 Concrete Culverts 5-1. Features Affecting Structure Shape and Capacity The following information applies to the design of rein- forced concrete culverts. Typical conduit shapes used for culverts are shown in Figure 5-1. a. Location. Ideally, the axis of a culvert should coincide with that of the natural streambed and the struc- ture should be straight and short. This may require modi- fication of the culvert alignment and grade. Often it is more practical to construct the culvert at right angles to the roadway. However, the cost of any change in stream channel location required to accomplish this should be balanced against the cost of a skewed alignment of the culvert, and changes in channel hydraulics should be considered. b. Grade and camber. The culvert invert gradient should be the same as the natural streambed to minimize erosion and silting problems. Foundation settlement should be countered by cambering the culvert to ensure positive drainage. c. Entrance and outlet conditions. It is often neces- sary to enlarge the natural channel a considerable distance downstream of the culvert to prevent backwater from entering the culvert. Also, enlargement of the culvert entrance may be required to prevent ponding above the culvert entrance. The entrance and outlet conditions of the culvert structure directly impact its hydraulic capacity. Rounding or beveling the entrance corners increases the hydraulic capacity, especially for short culverts of small cross section. Scour problems can occur when abrupt changes are made to the streambed Flow line at the entrance or outlet of the culvert. 5-2. Materials Table 5-1 lists the applicable standards for the materials used in the design of reinforced concrete culverts. 5-3. Installation a. Foundation material. Materials to be used for the culvert pipe foundation should be indicated on the drawings. Refer to the geotechnical foundation report for the project. EM 1110-2-2902 31 Oct 97 b. Bedding materials. Bedding class and materials for culverts should be indicated on the drawings. Bed - dings shown in the American Concrete Pipe Association's Concrete Pipe Design Manual (1992) are acceptable. When designing the bedding for a box culvert, assume the bedding material to be slightly yielding, and that a uni- form support pressure develops under the box section. 5-4. Loadings Assume that design loads for concrete culvert pipe are calculated as vertical pressures and that the horizontal pressures are controlled by the backfill requirements. Refer to Chapter 2 for typical loading calculations. Con- centrated live loads for highway or railroad loadings should be applied as required by the standards of the affected authority and in accordance with Chapter 2 of this manual. a. Railroad, highway, and aircraft loads. Culverts designed for loadings from railroads, highways, or aircraft need to satisfy the criteria of the affected authority. This manual presents data closely related to the requirements of the American Railway Engineering Association (AREA) (1996) and the American Association of State Highway Transportation Officials (AASHTO) Standard Specifications for Highway Bridges (AASHTO 1996). The method used to combine wheel live loads and earth loads on culverts is shown in Figure 5-2. The procedure presented in the Concrete Pipe Design Manual (American Concrete Pipe Association 1992) should be used to dis- tribute aircraft wheel loads through pavement stabs to the top of the culvert. Railroad or highway loads may be ignored when the induced vertical stress fields are equal to or less than 4.8 kPa (100 psf), a depth of 2.4 in (8 ft) for highway loadings, or 9 in (30 ft) for railroad loadings. Note that the railroad and highway loads as shown are in accordance with ASTM A 796 and include an impact factor of 50 percent, which is higher than the impact loads required by AREA or AASHTO criteria. b. Special point loads. Pressure bulb charts are acceptable for determining the nominal vertical stress fields from relatively small footings. Pressure bulbs for continuous and circular/square footings are shown in Figures 5-3 and 5-4. respectively. Consult a geotechnical engineer for lateral loads from surface surcharge loadings. 5-1 EM 1110-2-2902 31 Oct 97 CIRCULAR ARCH 'rcular Cage Outs Middle Elliptical Cage Inner Cog oner Circular oge ^ `-, Cove Outer Middle Co( Alddle Cage Inner Cage r-near..,• �ivrrnuwnv Figure 5-1. Precast culvert sections 5-2 VERTICAL ELLIPTICAL Inner Cage i HORIZONTAL ELLIPTICAL Wall EM 1110-2-2902 31 Oct 97 4800 (16) Med V'9 Load applied on Assum;� 4200 (14) E 3600 (12) a 3000 (10) a 2400 (8) 1800 (6) 1200 (4) 0 a 600 (2) 0 24 48 72 96' (500) (1000) (1500) (2000) Unit Load, kPa (Ibf./ft 2) Combined H2O highway live load and dead load Is a minimum at about I500mm (5 ft.) of cover, applied through a pavement 300mm (l ft.) thick. 12 000 (40) 9000 (30) a ti 4 0 a 6000 (20) i Cooper E80 Figure 5-2. Highway and railroad loads (ASTM A 796) 5-3 EM 1110-2.2902 31 Oct 97 Table S-1 Materials for Reinforced Concrete Culverts Materials Standard Description Reinforced concrete ASTM C 76 M or AASHTO M 170 - Covers the use of reinforced concrete pipe for conveyance of circular D-load rated Reinforced Concrete Culvert, Storm sewage, industrial waste, storm -water drainage, and culverts for Drain and Sewer Pipe pipe with diameters from 305 to 3,660 mm (12 to 144 in.). Reinforced concrete ASTM C 655 M or AASHTO M 242 - circular D4oad rated Reinforced Concrete D-Load Culvert, tested Storm Drain and Sewer Pipe Reinforced concrete ASTM C 506 or AASHTO M 206 - arch Reinforced Concrete Arch Culvert, Storm Drain and Sewer Pipe Reinforced concrete ASTM C 507 or AASHTO M 207 - elliptical Reinforced Concrete Elliptical Culvert, Storm Drain and Sewer Pipe Reinforced concrete ASTM C 361 M - Reinforced Concrete pressure pipe Low -Head Pressure Pipe Reinforced concrete ASTM C 789 M or AASHTO M 259 box Precast Reinforced Concrete Box Sections for Culverts, Storm Drains and Sewers Similar to ASTM C 76 except that pipe may be accepted based on the factory D-load testing of nonstandard pipe classes. Covers pipe with equivalent circular diameters of 380 through 3,350 mm (15 through 132 in.). Uses classes of pipe for horizontal elliptical pipe with equivalent diameters of 450 through 3,660 mm (18 through 144 in.) and vertical elliptical pipe with equivalent diameters of 910 through 3,660 mm (36 through 144 In.). Covers the use of pressure pipe for water heads up to 38 m (125 ft) in sizes from 305 through 2,740 mm (12 through 108 in.) in diameter. Covers the use of box culvert with more than 610 mm (2 ft) of earth cover over culverts that are intended for highway five loads. These sections range in size from 910-mm span by 610-mm rise (3-ft span by 2-ft rise) to a 3,050-mm span by 3,050-mm rise (10-ft span by 10-ft rise). Reinforced concrete ASTM C 850 M or AASHTO M 273 - Applies to box sections with highway loadings with direct earth box less than 0.6 m Precast Reinforced Concrete Box cover of less than 610 mm (2 ft). These sections range in size (2 ft) cover HS-20 Section for Culverts, Storm from a 910-mm span by 610-mm rise (3-ft span by 2-h rise) to a Drains and Sewers 3,660-mm span by 3,660-mm rise (12-ft span by 12-ft rise). 5-5. Methods of Analysis 4 = Ap H + Ep <_ = 0.33 (5'2) Wheel loads for highway HS 20 live loads may be distrib- Cc (-FT, uted in accordance with ASTM C 857. This standard includes roof live loads, dead loads, and impact loads. where a D-load pipe. Precast concrete sections (ASTM C 76, ASTM C 655, ASTM C 506, and ASTM C 507) are designed for D-loads related to the pipe class. Precast concrete sections (ASTM C 361, ASTM C 789, and ASTM. C 850) are designed in accordance with the pre- scriptive procedures defined within the applicable ASTM. Therefore, bedding factors should be selected from Table 5-2 for trenches and calculated by using Equations 5-1 and 5-2. When the pipe is in an embankment, use Table 5-3 to calculate the load factor & The value for Cc in Equation 5-2 should be taken from Figure 5-5. Use the Bf calculated by this procedure to calculate the D-load of the pipe. The hydraulic factor for precast concrete pipe should be one for culverts. Bf = CA (5 1) CN-X4 5-4 CA = conduit shape constant from Table 5-3 CN = parameter that is a function of the distribution of the vertical load and vertical reaction from Table 5-3 X = parameter that is a function of the area of the vertical projection of the pipe over which active lateral soil pressure is effective and is based on conduit shape from Table 5-3 A = the ratio of unit lateral soil pressure to unit vertical soil pressure based on conduit shape from Table 5-3 SouvAAaE �,.�I %tl coxrPni T2B6B 1B ��B 2B 30 I1B B 28 38 MINE 28 <B „■E SS BAi.L IMEMMM17B e £ r PRESSURE ISOBARS BASED ON THE BOUSSWESO EQUATION FOR SQUARE ANDLONGFOOTINGS, APPLICABLEONLVALONa LINE OAS SHOWN. �. Figure 5-3. Pressure bulb: square and continuous footings p = projection ratio, the vertical distance between the outside top of the pipe and the natural ground surface, divided by the outside horizon- tal diameter or span of the pipe Br C� = load coefficient for positive projection pipe from Figure 5-5 H = height of fill, in (ft), above top of pipe to top of fill BC = outside diameter or span of the conduit, in (ft) E = load coefficient based on conduit shape from Table 5-3 q = ratio of the lateral pressure to the total vertical load b. Box sections. Box sections are specified for the installed condition rather than a D-load rating, and these conditions are related to highway loadings and depth of EM 1110-2-2902 31 Oct 97 0 1 2 3 4 5 6 3 2 1 0 1 2 3 rib CONTW qS OF VERTICAL NORMAL STRESS BENEATH UNIFORMLY. LOADED CIRCULAR AREA ON LINEAR ELASTIC HALF -SPACE Figure 5-4. Pressure bulb: Circular area earth cover. ASTM C 789 has standard designs for AASHTO H 20 and HS 20 loadings when the depth of fill is more than 610 tutu ('Z ft) or for dead load only. ASTM C 850 provides standard designs for dead loads only or in combination with AASHTO H 20 or HS 20 loadings when earth cover is less than 610 into (2 ft). 5-6. Joints The three types of joints used in concrete culvert con- struction are the 0-ring gasket, the flat gasket, and the packed join[. Packed joints include mortar or mastic packing which should be used only when watertightness or joint movement is not a concern. Therefore, on culvert construction use a gasketed join[, and wrap the joint with a suitable filler fabric material to prevent soil migration into the pipe. Filter fabric requirements should be as stated in the geotechnical engineer's soils report for the project. a. Rubber gaskets for circular pipe. ASTM C 443 M requires this joint to hold an internal or external water pressure of 90 kPa (13 psi) for straight alignments and 70 kPa (]0 psi) for axially deflected alignments. 5-5 EM 1110-2-2902 31 OCII 97 Table 5-2 Design Value Parameters for Load Factor: Trenches shape Bedding Cradle Reinforcement Bedding Factor (Bd Circular (only) A (Concrete) As = 1.0% 4.8 0.4 3.4 0.0 (Plain Concrete) 2.8 All shapes B (Shaped) 1.9 All shapes C (Shaped) 1.5 Circular (only) D (Impermissible: Flat) 1.1 Table 5-3 Design Value Parameters for Load Factor: Embankments CN (Distribution Projection X (Lateral Projection Shape CA (Shape Factor) Bedding Class Factor) Ratio, p Factor) Circular: A - 0.33. E = 0.60 1.431 Class 8 (Shaped) 0.707 1.0 0.638 Class C (Shaped) 0.840 0.9 0.655 0.7 0.594 0.5 0.423 0.3 0.217 0.0 0.000 Horizontal Elliptical and Arch: A = 0.23, E = 0.35 1.337 Class B 0.630 0.9 0.421 Class C 0.763 0.7 0.369 0.5 0.268 0.3 0.148 Vertical Elliptical: A = 0.48. E - 0.73 1.021 Class B 0.516 0.9 0.718 Class C 0.615 0.7 0.639 0.5 0.457 0.3 0.238 b. External band gaskets for noncircular pipe. ASTM C 877 applies to arch, elliptical, and box pipe sec- tions. These sealing bands are adequate for external hydrostatic pressures of up to 90 kPa (13 psi). Joints on the installed pipe should be tested when watertightness is a concem. Sealing bands that meet this standard can be rubber and mastic or plastic film and mesh -reinforced mastic, c. Field pipe joint testing. When watertight joints ate required, one of the test methods referenced below should be used. (1) Low-pressure air test. ASTM C 924 covers exfd- lration testing of 100- to 610-mm (4- to 244n.) concrete pipe with gasketed joints and demonstrates the condition of the pipe prior to backfdling. (2) Infiltralion/exMivation test. ASTM C 969 covers the testing of concrete pipes up to 210 in (700 ft) in length between manholes. The infiltration test is used when the groundwater level is 1,800 mot (6 ft) above the crown of the pipe and allows a leakage including man- holes of 18.5 4(mmdiameter) (km) (24 hr) ((200 gal/ (in. -diameter) (mile) (24 hr)). The exfiltration test is used when the groundwater level is 910 mm (3 ft) below the invert of the pipe and allows a leakage including man- holes of 18.5 L/(mm-diameter) (km) (24 hr) ((200 gal/ (in. -diameter) (mile) (24 hr)) with an average head of 0.9 m (3 ft) or less. The Corps of Engineers exfrltralion test allows a leakage rate of 23.1 U(mm-diameter) (km) (24 hr) ((250 gaV(in: diameter) (mile) (24 hr)) for pipeline conslruction. This lest method does not apply to water retention structures. 1a 12 - e We", TgENC pNOPleTF o A� �TroN „o 10 - aq A M19 e,, 0 w as- �p1t�N �ECS\ON P Eh P d 2 - Kq=0.19 0 0 4 8 12 16 20 VALUES OF LOAD COEFFICIENT, C. Figure 5-5. Load coefficient C, for positive projection embankment condition EM 1110-2-2902 31 Oct 97 (3) Joint acceptance test. ASTM C 1103 covers the testing of joints by using air or water under low pressure to demonstrate the joint integrity of pipes with a diameter greater than 675 mm (27 in.). The internal pressure of the pipe should be maintained at 24 kPa (3.5 psi) above the design groundwater pressure of the pipe for 5 seconds. This test is used as a go/no-go test for the joint prior to backfilling the pipe. (4) Negative air test. ASTM C 1214 covers the test- ing of concrete pipe with a negative air pressure for 100- to 910-mm- (4- to 36-in.-) diameter pipe using gasketed joints. Testing times and air loss vary based on pipe diameter for the pressure to drop from 177.8 to 127 mm (7 to 5 in.) of mercury. 5-7. Camber Where considerable foundation settlement is likely to occur, camber should be used to ensure positive drainage and to accommodate the extension of the pipe due to settlement. 5-7 Chapter 6 Plastic Pipe for Other Applications 6-1. General a. Plastic pipes. Plastic pipes are available in both solid wall and profile wall thermoplastic acrylonitrile- butadiene-styrene (ABS), high -density polyethylene (HDPE), and polyvinyl chloride (PVC) pipes, as well as thermoset reinforced plastic mortar (RPM) pipes. They all possess the general attributes normally associated with plastics including light weight, long lengths, tight joints, and resistance to normal atmospheric corrosion. All these pipes are flexible, and in general the design considerations are similar to metal pipes. However, due to the visco- elastic nature of these materials, the time under load con- dition may require that long-term material properties be used in the design. Additionally, each specific grade of material, as well as the type of pipe (i.e., solid or profile) dictates the design properties. b. Selection considerations. Plastic pipes vary sig- nificantly in strength, stiffness, and performance. Differ- ences depend more on their design and intended use than on the specific pipe wall material. A thorough evaluation of the intended use and detailed material, jointing, and backfill specifications is necessary to ensure performance. Use of plastic pipes in drainage and subdrainage applica- tions is increasing. However, their use in low cover with heavy wheel loads or high cover applications is limited (refer to paragraph 6-3). Plastic pipe will not be used through embankments of dams and levees without approval from HQUSACE. Plastic pipes will typically be used for drainage piping behind structures. 6-2. Materials a. Plastic materials. The piping materials discussed in this chapter include ABS, HDPE, and PVC thermo- plastic pipes and RPM thermosetting resin pipes. Thermoplastic pipes include both solid wall (smooth, solid pipe wall extrusions), as well as profile wall (corrugated, ribbed, etc.) pipes that provide the indicated level of pipe stiffness while providing a limited wall area to carry ring compression. b. Profile wall pipe. These pipes are commonly more economical, especially in diameters exceeding 200 mm (8 in.). However, they provide 50 to 70 percent of the wall area when compared to equal stiffness solid wall pipes of the same material. This limits their EM 1110-2-2902 31 Oct 97 load -carrying capability in high cover applications and also limits beam strength. c. Reinforced plastic mortar. These pipes are strain sensitive. If the surface resin layer strain cracks, the reinforcing glass is exposed to corrosion. The manu- facturer will supply strain limits which are typically in the 0.5 to 1.0 percent range. Control of deflection and local- ized deformation are very important in design and construction. d. Plastic pipe systems. These systems are summa- rized in Table 6-1. Typical mechanical properties for plastic pipe design are shown in Table 6-2, and average values for the modulus of soil reaction are shown in Table 6-3. e. Applications. Intended applications are provided in the American Society for Testing and Materials (ASTM) or American Association of State Highway and Transportation Officials (AASHTO) specification. The highest (most stringent) use is summarized above. Gener- ally, piping systems can be downgraded in application and provide excellent performance, but they cannot be upgraded. Sanitary sewer pipes perform well in culvert, drainage, and subdrainage (if perforations are provided) applications. However, unperforated land drainage pipes do not perform well as culverts or sewers. (1) Culverts. For culvert applications, the exposed ends of some types of plastic pipes need protection from exposure to ultraviolet, thermal cycling, etc. Concrete or metal end sections, headwalls, or other end protection is recommended. (2) Pipe stiffness. Product specifications typically provide minimum pipe stiffness levels. Pipe stiffness and its relationship to AASHTO Flexibility Factor (FF) limits for adequate installation stiffness are provided in para- graph 6-5. In installations where poorly graded granular (SP, GP, etc.) or cohesive (CL or MQ backfill materials are to be used, specifying a stiffer pipe than required by the minimum design criteria is recommended (refer to paragraph 6-5). (3) Gravity flow. The listed materials, except as noted, are gravity flow piping systemslimited to applica- tions where internal hydrostatic heads will not exceed 7.6 in (25 ft) of water. f. Joints. The types of joints available for each system are shown in Table 6-4. When watertight joints 6-1 EM 1110.2-2902 31 Oct 97 Table 6.1 Plastic Pipe Systeme Standard Primary Use Diameters Joints AASHTO M 294 Storm sewer when the 305 to 900 men Various - must be specified for Corrugated HDPE Pipe smooth interior wall (12 to 36 in.) degree of performance. (Profile Wall) (M 294-S) is specified, land drainage when it is not (M 294-C) ASTM D 2680 Sanitary sewer 200 to 380 mm Solvent weld (watertight) ABS Composite Pipe (8 to 15 in.) (Profile Wall) ASTM D 2680 Sanitary sewer 200 to 380 men Gasketed or solvent weld PVC Composite Pipe (8 to 15 in.) (watertight) (Profile Wall) ASTM D 3034 Sanitary sewer 100 to 380 ram Gasketed or solvent weld PVC Pipe (Solid Wall) (4 to 15 in.) (watertight) ASTM D 3262 Sanitary sewer 76 to 1,240 men Gasketed RPM Pipe (Solid Wall) (3 to 49 in.) ASTM F 667 Land drainage 200 to 610 men Various - must be specified for Corrugated HDPE Pipe (8 to 24 in.) degree of performance (Profile Wall) ASTM F 714 Sanitary sewer or 76 to 1,200 mm Fusion welded HDPE Pipe (Solid Wall) pressure (3 to 48 in.) ASTM F 794 Sanitary sewer 200 to 1,200 men Gasketed (watertight) PVC Pipe (Profile Wall) (8 to 48 in.) ASTM F 894 Sanitary sewer 460 to 2,450 men Gasketed or fusion welded Profile Wall HDPE Pipe (18 to 96 in.) (watertight) ASTM F 949 Sanitary sewer 200 to 1,200 mm Gasketed (watertight) Profile Wall PVC Pipe (8 to 48 in.) AASHTO M 304 Nonpressure storm drains, 100 to 1,200 mm Soiltight or watertight: bells, culverts, underdrains, and other (4 to 48 in.) external sleeves, internal sleeves, subsurface drainage systems and band couplers are required, gasketed joints meeting ASTM D 3212, solvent welded, or fusion welded joints may be used. Solvent welded and fusion welded joints are as strong as the pipe and provide excellent pull -apart strength for slope drain and other applications. However, PVC solvent welded joints should not be specified for installation in wet conditions or when temperatures are cold. Fusion welding requires special equipment and skill, and it can be time-consuming and, in remote areas or with large pipes, costly. g. Granular baclfill. Culvert and drainage applica- tions with granular backftils require soil -tight joints to prevent the migration of fine backfili materials into the pipe. Gasketed, solvent welded, or fusion welded joints are recommended unless each joint is wrapped with a geotextile. 6-2 6-3. Installation The strength of all plastic pipe systems depends on the quality and placement of the bedding and backfill mate- rial. Unless flowable concrete or controlled low -strength materials (CL, SPA) are used, ASTM D 2321 will be followed for all installations except for perforated pipes in subdrainage applications. a. Backfill materials. Using ASTM Class IVA materials (CL, NIL, etc.) is not recommended. Clayey and silty materials may provide acceptable performance only in low five load and low cover less than 3 in (10 ft) applications where they can be placed and compacted in dry conditions at optimum moisture levels. They do not apply where they may become saturated or inundated EM 1110-2-2902 31 Oct 97 Table 6-2 Mechanical Properties for Plastic Pipe Design Initial initial 50-Year 50-Year Minimum Minimum Minimum Minimum Strain Pipe Tensile Modulus Tensile Modulus of Limit Stiffness Type of Strength of Elasticity Strength Elasticity Percent kPa Pipe MPa (psi) MPa (psi) Standard Cell Class MPa (psi) MPa (psi) N (psi) Smooth 20.7 758 ASTM D 3350, 335434C 9.93 152 5 Varies Wall, PE (3,000) (110,000) ASTM F 714 (1,440) (22,000) Corrugated 20.7 758 ASTM D 3350, 335412C 6.21 152 5 Varies PE (3,D00) (110,000) AASHTO M 294 (900) (22,000) Ribbed, PE 20.7 758 ASTM D 3350, 335434C 9.93 152 5 320 (3,D00) (110,000) AASHTO M 278 (1,440) (22,000) (46) ASTM F 679 Ribbed, PE 20.7 758 ASTM D 3350, 335434C 9.93 152 5 320 (3,000) (110,000) AASHTO M 278 (1,440) (22,000) (46) ASTM F 679 Smooth 48.3 2,758 ASTM D 1754, 12454C 25.51 965 5 320 Wall, PVC (7,000) (400,000) AASHTO M 278 (3,700) (140,400) (46) ASTM F 679 Smooth 41.4 3,034 ASTM D 1784, 12364C 17.93 1,092 3.5 320 Well, PVC (6,000) (440.000) ASTM F 679 (2,600) (158.400) (46) Ribbed, 41.4 3,034 ASTM D 1784, 12454C 17.93 1,092 3.5 70 (10) PVC (6,000) (440,000) ASTM F 794 (2,600) (158,400) 320 (46) Ribbed, 48.3 2,758 ASTM D 1784, 12454C 25.51 965 5 348 PVC (7,000) (400,000) ASTM F 794 8 (3,700) (140.000) (50) ASTM F 949 PVC 48.3 2,758 ASTM D 1784, 12454C 25.51 965 5 1,380 Composite (7,000) (400,000) ASTM D 2680 (3,700) (140,000) (200) during service. When used, these materials must be approved by the geotechnical engineer. b. Pipe envelope. The pipe envelope and bedding and backfili terms are illustrated in Figure 6-1. c. Seepage control. When seepage along the pipe- line is a consideration, a drainage fill detail is required as discussed in paragraph 1-6.e. If flowable concrete, CLSM, or other such materials are used, note that these materials do not adhere to plastics and will not control seepage unless a sufficient number of rubber water stops (gaskets) are used. Piping systems intended for sanitary sewer applications offer water stop gaskets that seal to the outer pipe wall and bond to concrete. d. Subdrainage applications. For this application, open grade, nonplastic granular backfill materials compacted to 90 percent relative density in accordance with ASTM D 4254 and D 4253 will be used to fill the pipe zone above the invert. Granular backfill should be wrapped in a suitable geotextile to prevent the migration of soil fines into the granular material. e. Foundation. Foundation is the in situ material struck to grade or the trench bottom below the pipe and its bedding layer. The foundation supports the pipe and maintains its grade. Plastic pipes, due to their viscoelastic properties, do not provide the necessary long-term beam strength to bridge soft spots or settlement of the foundation. The foundation must carry the fill loads with 6-3 EM 1111G-2-2902 31 QC1 97 Table 6.3 Average Values of Modulus of Soil Reaction E (For Initial Flexible Pipe Deflection) E for Degree of Compaction of Bedding, in MPa (psi) Slight <85% Moderate, 85%- 95% High >95% Soil Type Pipe Bedding Material Proctor, 40% Proctor, 40%-70% Proctor, >70% (Unified Classification Systems) Dumped Relative Density Relative Density Relative Density Fine-grained soils (LL > 50)b Sells. with medium to high plasticity CH, MH, CH-MH No data available; consult a competent soils engineer; otherwise use E = 0 Fine-grained soils (LL < 50) Soils with medium to no plasticity, CL, 0.34 1.38 2.76 6.89 ML, ML-CL, with less than 25%coarse- (50) (200) (400) (1,000) grained particles Fine-grained soils (LL < 50) Soils with medium to no plasticity, CL, ML, ML-CL, with more than 25% 0,69 2.76 6.89 13.79 coarse -grained particles (100) (400) (1,000) (2,000) Coarss-grained soils with fines GM, GC, SM, SC contains more than 12% fines Coarse -grained soils 1.38 6.89 13.79 20.68 Little or no fines GW, GP, SW, SPc (200) (1,000) (2,000) (3,000) contains less than 12% fines Crushed rock 6.89 20.68 20.68 20.68 (1,000) (3,000) (3,000) (3,000) Note: Standard Proctors in accordance with ASTM D 698 are used with this table. Values applicable only for fills less than 50 it (15 m). Table does not include any safety factor. For use in predicting initial deflections only, appropriate Deflection Lag Factor must be applied for long-term deflections. °ASTM Designation D 2487, USBR Designation E-3. bLL = liquid limit. r0r any borderline soil beginning with one of these symbols (i.e. GM -GC, GC -SC). Table f.4 Requirements for Joints Type of Joint Standards Requirements Gravity -flow ASTM D 3212 Internal Pressure: Certified test reports are required for each diameter of pipe used. gasketed External Pressure: 7620 mm (25 it) water head for 10 minutes when subjected to 560 mm (22 in.) of mercury, 7620 mm (26 it) of water vacuum for 10 minutes. Pressure -rated ASTM D 3919, Internal Pressure: ASTM 0 3919, Requires pressure testing, ASTM C 900, same gaskated ASTM C 900, 4 requirements of D 3919, American Water Works Association (AWWA) C 950, same AWWA C 950 requirements as ASTM D 4161. External Pressure: ASTM D 3919, Vacuum tested to only 7620 mm (25 it) of water at any pressure rating, ASTM C 900, same requirements as D 3919, AWWA C 950, same requirement as ASTM D 4161. Pressure -rated ASTM D 4161 Internal Pressure: Tested to twice the rated pressure for pressure pipe or 200 kPa and nonpres- (29 psi) for non-pressurepipe. sure lasketed g External Pressure: Requires an external rating of 8230 tern (27 it) of water head for 10 minutes. Solvent joints --- Solvent cemented -pints for PVC (not recommended in wet conditions) and ABS pipes typically have lightness requirements. These joints are not recommended for ABS or PVC pipe as there are no standards for joint integrity. Butt -fused --- For HDPE solid -waft. No standards for joint integrity. Extrusion -welded --- For HDPE. No standards for pint integrity. (#I Final bockfill 0••'O °.o o'0 o Initial Backfill Pipe zone o 0 00 V 4" Hounching wd o 0 o co 0 0' o oe Bedding Foundotion Pipe zone TYPICAL PIPE BACKFILL Final bockfill Flowoble bockfill Foundation FLOWABLE PIPE BACKFILL Figure 6-1. Flexible pipe backfill EM 1110-2-2902 31 Oct 97 6-5 EM 1110-2-2902 31 Oct 97 a suitable limit on settlements which will be directly exhibited as grade changes that occur over the pipe as sags develop in the pipe. Where the foundation is inade- quate, it may be improved by overexcavation and replace- ment with compacted ASTM D 2321 backfill materials, surcharged to induce the settlement beforehand. Concrete cradles and other pipe supports should not be used. f. Bedding. Bedding is used to support the pipe directly over the foundation material. For plastic pipe, the bedding material is typically granular. The proper selec- tion of bedding material ensures the proper soil -pipe inter- action and the development of pipe strength. The strength of the plastic pipe is built in the trench. Concrete cradles should not be used under plastic pipe, because these pipes are subject to wall crushing at the springline or local buckling at the contact point between the pipe and the cradle. g. Haunching. Haunching the volume of backfill supports the pipe from the top of the bedding to the springline of the pipe. Compaction of the pipe haunch areas is critical to the successful installation of plastic pipes and prevents pipe sagging in the haunch area. Special construction procedures are necessary when installing plastic pipe in a trench box, as the haunching material can slough away from the pipe wall when the trench box is advanced. The designer should review the contractor's construction procedures when using a trench box. h. Initial backfill. Initial backfill is the material placed above the springline and 305 mm (12 in.) over the pipe. Completion of this zone with well -compacted gran- ular material ensures that the pipe strength is developed. i. Final backfill. Final backfill is the material that completes the pipe installation and brings the trench to final grade. Proper compaction is required in the trench to limit surface settlements. A minimum depth of final backfill over plastic pipe of 610 mm (2 ft) is recommended when installing plastic pipe under paved surfaces. Since these soils do not completely rebound, the surface pavement will crack and settle with time if less than minimum cover is used. Therefore, a well - compacted backfill is required for the pipe to function properly. j. Flowable backfill. Plowable backfill is used to replace the pipe zone materials described above. Plowable backfill places a CLSM around the pipe to 6-6 ensure good support for the pipe, yet uses a material that can be easily removed if the pipe needs to be replaced in the future. 6.4. Loadings Vertical trench loads for plastic pipe are calculated as indicated in Chapter 2. The horizontal pressures are controlled by the granular backfill requirements. These loads are calculated as shown in Chapter 2. Concentrated live loads for plastic pipe are designed for highway or railroad loadings as required by standards of the affected authority. Normally, these pipes will require a casing pipe when crossing under highways and railroads, or the pipe may be encased in CLSM. 6-5. Methods of Analysis Plastic pipe analysis requires the designer to check values that include pipe stiffness, pipe deflection, ring buckling strength, hydrostatic wall buckling, wall crushing strength, and wall strain cracking. a. Pipe stiffness. When plastic pipe is installed in granular backfills, the stiffness of the plastic pipe selected will affect the end performance. Stiffness for plastic pipes is most widely discussed in terms of pipe stiffness (RAI) which must be measured by the ASTM D 2412 test. Most plastic pipe standards have specific, minimum required pipe stiffness levels. While pipe stiffness is used to estimate deflections due to service loads, stiffness is also the primary factor in controlling installation deflec- tions. AASHTO controls installation deflection with a flexibility factor (FF) limit indicated in Equations 6-1 and 6-2. 2 FF = « 1000 5 Cpp (6-1) E( PS = El 2 CPS (6 2) 0.149R3 D where D = mean pipe diameter, m (in.) E = the initial modulus (Young's modulus) of the pipe wall material, N/mZ (psi) l pipe wall moment of inertia, m4/m (in 4/in.) Cpp = Constant 0.542 metric (95 english) PS = pipe stiffness, N/m/m (lbs/inJin.) R = mean pipe radius, in (in.) Cps = Constant: 98946 metric (565 english) b. Deflection. (1) Excessive pipe deflections should not occur if the proper pipe is selected and it is properly installed and backfilled with granular materials. However, when pipes are installed in cohesive soils, the deflection can be exces- sive. Deflections occur from installation loadings (the placement and compaction of backfill) and service loads due to soil cover and live loads. (2) In installations, where heavy compaction equip- ment is often used, or when difficult to compact backfill materials (GP, SP, CL, ML, etc.) are used, specifying a minimum pipe stiffness of 317 kPa (46 psi) or twice that required by Equation 6-2, whichever is less, is desirable to facilitate backfill compaction and control installation deflections. (3) Deflections under service loads depend mostly on the quality and compaction level of the backfill material in the pipe envelope. Service load deflections are gener- ally evaluated by using Spangler's Iowa Formula. How- ever, it significantly overpredicts deflections for stiffer pipes (pipe stiffnesses greater than 4,790 N/m/m (100lb/in./in.) and underpredicts deflections for less stiff pipes (pipe stiffnesses less than 960 N/m/m (20 lb/in./in.). In both cases, the error is roughly a factor of 2.0. The form of the Iowa Formula easiest to use is shown in Equation 6-3. A (_ DL K P t 100 (6-3) 0.149 (PS) + 0.061 (E ) where AY/D = pipe deflection, percent DL = deflection lag factor = 1.0 minimum value for use only with granu- lar backfill and if the full soil prism load is assumed to act on the pipe = 1.5 minimum value for use with granular backfill and assumed trench loadings = 2.5 minimum value for use with CL, ML backfills, for conditions where the back - fill can become saturated, etc. EM 1110-2-2902 31 Oct 97 K = bedding constant (typically 0.11) P = service load pressure on the, crown of the pipe, N/m2 (psi) PS = pipe stiffness, N/m/m (lb/in./in.) E' = modulus of soil reaction as detetnined by the geotechnical engineer, N/m2 (psi) Note: Table 6-3 provides generally accepted values that may apply to specific site conditions and backfill mate- rials if they do not become saturated or inundated. b. Wall stress (crushing). Wall stress is evaluated on the basis of conventional ring compression formulas. Because of the time -dependent strength levels of plastic materials, long-term loads such as soil and other dead loads must be evaluated against the material's long-term (50-year) strength. Very short term loads, such as rolling vehicle loads, may be evaluated using initial properties. Use Equations 6-4 through 6-6 to evaluate wall stress. DPST (6-4) TST - 2 DPLT 6 5 TLT = 2 ( ) A > 2 I TST + TLT Ir106 (6-6) I\ fi f50 J where TST = thrust due to short-term loads D = pipe diameter or span, in (ft) PST = short-term loading pressuree at the top of the pipe, N/m2 (psl) TLT = thrust due to long-term loads PLT = long-term loading pressure at the top of the pipe, N/m2 (Psf) A = required wall area using a minimum factor of safety of 2.0 (A/10 6 in 2/ft) 6-7 EM 1110-2-2902 31 Oct 97 f = initial tensile strength level, N/m2 (psi) (Table 6-2) f50 = 50-year tensile strength level, N/m2 (psi) (Table 6-2) c. Ring buckling. The backfilled pipe may buckle whether the groundwater table is above the bottom of the pipe or not. The critical buckling stress may be evaluated by the AASHTO formula shown in Equation 6-7. K EI Pcr = C (6-8) where Pcr = critical buckling pressure, N/m2 (psf) C = ovality factor at: 0 % deflection, C = 1.0; 1%n, 0.91; 2%, 0.84; 3%, 0.76; 4%, 0.70, and 5°%, 0.64 fcr 0.77 R BMrE/ (6-7) K = constant 1.5 (]0)-12 metric, 216 non-Sl = _ A 0.149R3 v = Poisson's ratio for the pipe wall material (typically 0.33 to 0.45) other factors same as where Equation 6-7 (2) A factor of safety of 2.0 is typically applied for fcr = maximum, critical stress in the pipe wall, N/m2 round pipe. However, note that 5 percent pipe deflection (psi), using a factor of safety of 2.0 reduces Pcr to 64 percent of its calculated value. R = mean pipe radius, m (in.) A = pipe wall area, mm2/m (in.2/in.) B = water buoyancy factor = 1 - 0.33 hKlh ha, = height of water surface above the top of the pipe, m (ft) h = height of cover above the top of the pipe, m (ft) Ms = Soil modulus (of the backfill material, N/m2 (psi)), as determined by a geotechnical engineer E = 50-year modulus of elasticity of the pipe wall material, N/m2 (psi) (Table 6-2) / = pipe wall moment of inertia, mm4/m (in.4/in.) d. Hydrostatic buckling. (1) When pipes are submerged but not adequately backfilled, such as service lines laid on the bottom of a lake, the critical hydrostatic pressure to cause buckling can be evaluated by the Timoshenko buckling formula provided in Equation 6-8. The variable C is used to account for decrease in buckling stress due to pipe out of roundness Pcr. 6-8 (3) Equation 6-8 can be conservatively applied to hydrostatic uplift forces acting on the invert of round pipes. e. Wall strain cracking. Wall strain cracking is a common mode of failure in plastic pipe, especially RPM and reinforced thermosetting resin (RTR) pipes, the two common forms of fiberglass pipe. Refer to ASTM D 3839 for the standard practice to install these pipes and to ASTM D 3262 for the minimum allowable strain limits for these pipes. The manufacturer of the pipe material must provide the maximum allowable wall strain limit based upon ASTM D 3262. Also, AASHTO provides information on the allowable long-term strain limits for many plastics. Excessive wall strain in fiberglass pipe will lead to an accelerated premature failure of the pipe. The typical long-term strain value for HDPE and PVC is 5 percent at a modulus of 2,760 MPa (400,000 psi), or 3.5 percent for PVC with a modulus of 3,030 MPa (440,000 psi). Refer to Equation 6-9. 0.03 �Y Eb _ [max D S Elimit (6-9) D I - 0.02AY FS D where Eb = bending strain due to deflection, percent t� = pipe wall thickness, m (in.) D = mean pipe diameter, m (in.) AYID = pipe deflection, percent cli,U = maximum long-term strain limit of pipe wall, percent FS = factor of safety (2.0 recommended) f. Flowable bacoll. This material has a compres- sive strength less than 3A MPa (500 psi). Flexural EM 1110-2.2902 31 OCt 97 strength is not a concern since cracking of the backfrll material does not control the design of the pipe. A cracked backfdl material would still form an arch over the pipe and provide adequate support. 6.6. Joints Requirements for joints are provided in Table 6-4. 6-7. Camber Where considerable foundation settlement is likely to occur, camber should be used to ensure positive drain- age and to accommodate the extension of the pipe due to settlement. 6-9 Chapter 7 Ductile Iron Pipe and Steel Pipe for Other Applications 7-1. General a. Ductile iron pipe (DIP). Ductile iron pipe has replaced cast iron pipe in use and application. Ductile iron pipe is used under levees and for water mains and other installations where fluids are carried under pressure. It is also suitable for pressure sewers and for gravity sewers where watertightness is essential. It can resist relatively high internal and external pressures and corro- sion in most soils. However, it is subject to corrosion caused by acids, highly septic sewage, and acid soils. It is generally available in sizes up to about 1,625 mm (64 in.). Flexible bolted joints are required under levees and in other locations where differential settlement is anticipated. 6. Steel pipe. Steel pipe should be used for dis- charge lines from pumping stations for flood protection work. In general, these pipes should be carried over rather than through the levee. Steel pipe should be designed in accordance with American Water Works Association (AWWA) MI I (AWWA 1985). 7-2. Materials The standards listed in Table 7-1 may be referenced by designers using these materials. EM 1110-2-2902 31 Oct 97 7-3. Installation Ductile iron pipe is normally installed in the trench condi- tion. When using first-class beddings and a backfill compacted to 90 percent standard proctor, American Association of State Highway and Transporation Officials (AASHTO) T-99 or better, the values shown below apply. When other beddings and backfill conditions are used, refer to American Society for Testing and Materials (ASTM) A 746 for loading constants. 7-4. Loadings Because ductile iron pipe is normally installed only in the trench condition, this is the only loading condition dis- cussed in this chapter. 7-5. Methods of Analysis Equation 7-1 for bending stress and Equation 7-2 for deflection are used to calculate the maximum trench load the pipe can withstand for earth and live loads in terms of the vertical field stress as N/m2 (psi). It is recommended that a Type 4 (ASTM A 746) bedding be used and that actual pipe beddings and backfills be verified by a geo- technical engineer. Table 7-1 Materials for Ductile Iron and Steel Pipe Materials Standard Notes Ductile Iron ASTM A 746 - Ductile Iron Sewer Pipe This standard covers ductile iron pipe with push -on Pipe joints. Loading covered for this pipe is a trench condition for cement -mortar -lined or asphaltic4ined pipe. AWWA C150/A21.50 American National Standard for the .-- Thickness Design of Ductile -Iron Pipe AW WA C110/A21.10, American National Standard for Ductile- There is a compatible standard from Amencan Sod - Iron and Gray -Iron Fittings 3 in. through 48 in. (75 mm thru ety of Mechanical Engineers (ASME). 1220 mm for Water and Other Liquids AWWA C115/A21.15, American National Standard for Flanged There is a compatible standard fr= ASME. Ductile -Iron Pipe with Threaded Flanges Steel Pipe AISI 1989, Welded Steel Pipe -Steel Plate --- Engineering Data -Vol. 3 7-1 EM 1110-2-2902 31 Oct 97 Pv = 3 D2 D t2 t f 8— Et + 0.732 D 1 t (7-1) where (for bedding Type 4 per ASTM A 746 similar to first-class bedding) P, = trench load, earth plus live, N/m2 (psi) f = design maximum stress, 330 N/m2 (48,000 psi) D = outside diameter, mm (in.) t = net pipe thickness, mm (in.) Kb = bending moment coefficient, 0.157 Kx = deflection coefficient, 0.096 E = modulus of elasticity, 165,475 MPa (24,000,000 psi) e = modulus of soil reaction, 3.5 MPa (500 psi) PV = #D) 8E + 0.732 Et x F (7-2) 1 tm 7-2 where tm = minimum manufacturing thickness, t+2turn, t+0.08in AX/D = design deflection/diameter, 0.03 for con- crete lined, 0.05 for asphaltic or plastic lined 7-6. Joints Use the materials referenced above for the type of joint used. The two available types are push -on and flanged. Joints can be restrained for thrust forces by using thrust blocks, restrained joints, or tie rods. Thrust restraint is required at tees, closed valves, reducers, dead ends, or wyes. 7-7. Camber Where considerable foundation settlement is likely to occur, camber should be used to ensure positive drainage and to accommodate the extension of the pipe due to settlement. Chapter 8 Pipe Jacking 8-1. General Pipe jacking is a method of installing a pipe under road- ways, railways, runways or highways without using an open cut trench. The pipe jacking procedure uses a casing pipe of steel or reinforced concrete that is jacked through the soil. Sizes range from 460 to 2,740 min (18 to 108 in.). Maximum jacking loads are controlled by pumping bentonite or suitable lubricants around the out- side of the pipe during the jacking operation. Typically, jacks are oversized so they can be operated at a lower pressure and maintain a reserve jacking capacity. It is common to use a 24-hour operation when pushing pipe, reducing the possibility that the pipe will freeze or "set' in the ground. Another common practice is to place 38-mm- (1.5-in:) diameter grout plugs in each section of pipe up to 1,220-mm (48-in.) diameter and three plugs in each section of pipe over 1,370 mm (54 in.) in diameter. These plugs are used to pump lubricants around the outside of the pipe during the jacking operation and to pump grout around the outside of the pipe after the push is completed. Refer to Figure 8-1 for casing pipe details. In accordance with the intent of EM 1110-2-1913 and para 1-6.e., a drainage detail shall be provided that is adequate to prevent formation of excess seepage gradients and piping in the region of the landside toe of levees underlain by pipes installed by jacking or other "trench - less" methods. The detail may consist of buried drainage features with suitable filter, drainage collection and dis- charge elements, an inverted filter and weight berm above the toe of the levee and the pipe installation pit, or a combination of these. 8-2. Materials a. Steel pipe. New and unused sections of steel pipe are used for the casing pipe. Steel casing pipe sections are then joined with full circumferential welds and pushed through the soil. Typical nominal wall thicknesses for steel casing pipe indicated in Table 8-1 should be coordi- nated with the appropriate highway or railroad authorities as necessary. b. Concrete pipe. The minimum recommended com- pressive strength for jacked concrete pipe is 35 MPa (5,000 psi). Typical axial jacking loads for concrete pipe are shown in Table 8-2. Concrete pipe should have full circumferential reinforcement and supplemental joint EM 1110-2-2902 31 Oct 97 reinforcement when ASTM C 761vI pipe is used. Provisions for intermediate jacking rings should be incorporated in the design when pushes are longer than 105 m (350 ft), and joints should be cushioned with plywood, manila rope, jute, or oakum. Pipe alignment for jacked pipe should be straight. Bell and spigots should be concentric with the pipe wall, and the outside wall should be straight walled with no bells. 8-3. Installation a. Excavation. Pipe jacking operations require the excavation of a suitable jacking pit. Pits need to be shored because the side walls are normally cut vertical to conserve space. Pits should be large enough to accom- modate the backstop, jacking equipment, spacer, muck removal equipment, and lubricant pump and lines. They should also have minimal walking room on each side of the jacking equipment. All equipment is normally cen- tered along the center line of the casing pipe. b. Backstop. The backstop is a rigid plate placed between the jack and the back wall of the pit that is used to distribute the jacking load into the ground. The load required to push the pipe through the ground depends on the method and lubricants used and equipment capacity. Small -diameter pipe can be jacked using a shoe on the front of the pipe. Large -diameter pipe can use an auger on the front of the pipe to cut the face material away and then push the muck through the pipe for removal. On pipe in nonrunning soils and that is large enough for workers to enter, hand excavation at the face of the pipe is possible. C. Set. The casing pipe can "set' or freeze in the d ei ther when inadequate jacking force is available or when operation is stopped for a period of time. To prevent this set condition from occurring, the operation can use lubricants, oversized jacks, and a continuous operation. 8-4. Loadings on Installed Pipe a. Prism weight. The earth load on a jacked pipe is normally the prism weight of soil above the crown of the pipe. However, the full prism load does not occur unless the soil is saturated. b. Cohesion of soil overburden. Cohesion of the overburden soil is used to reduce the earth load on the installed casing pipe as indicated by Equation 8-1. Typi- cal values of cohesion are shown in Table 8-3. 8-1 EM 1110-2.2902 31 OCt 97 Spacers Steel casing p pe Stainless steel band or clamp (Typ.) Carrier pipe Type of joint 1100mm 4' A 590m 2' ax. ax. Wood skids SKID DETAILS NO SCALE Stainless steel band Carri Largest outside diameter of bell Tc joint or gland 150mm (6") 13mm 18-25mm Steel Carrier pipe casing pipe Wood skids Spacers Bc SECTION f� NO SCALE 25mm (1) Stainless 30 Mil membrane steel band or clamp PVC finer material with suitable corrosion Casing pipe 2D E proof fastener a T E N � Carrier pipe < L 30 Mil membrane END SEAL DETAIL PVC liner material FOR CASING PIPE NO SCALE mm CLEARANCE DISTANCE er pipe size EC TC Or less (") ("-1'� 200mm 18mm 25-37mm 250mm l gmm 25-37mm 300mm 18mm 25-37 345mm 25mm 25-37mm (14") (1") (1"-1 ") 400mm 25mm 50-75mm Figure 8-1. Casing pipe details 8-2 Figure 8-1. Casing pipe details 8-2 EM 1110-2-2902 31 Oct 97 Table 8-1 Recommended Steel Pipe Nominal Wall Thicknesses Pipe OD Railroad Highway Nominal Actual Bare Coated Bare Coated mm (in.) mm (in.) mm (in.) mm (in.) mm (in.) mm (in.) 200 (8) 220 (8.625) 6(0.250) 4.5 (0.188) 6(0.250) 4.5 (0.188) 250 (10) 270 (10.75) 6(0.250) 4.5 (0.188) 6(0.250) 4.5 (0.188) 300 (12) 320 (12.75) 6(0.250) 4.5 (0.188) 6(0.250) 4.5 (0.188) 350 (14) 350 (14) 7(0.281) 5 (0.219) 6(0.250) 5 (0.219) 400 (16) 400 (16) 7(0.281) 5 (0.219) 6(0.250) 5 (0.219) 460 (18) 460 (18) 8 (0.312) 6 (0.250) 6(0.250) 6 (0250) 510 (20) 510 (20) 9 (0.344) 7 (0.281) 8(0.312) 6 (0.250) 610 (24) 610 (24) 10 (0.406) 9 (0.344) 8(0.312) 6 (0.250) 760 (30) 760 (30) 12 (0.469) 10 (0.406) 9(0.375) 9 (0.375) 910 (36) 910 (36) 13 (0.532) 12 (0.469) 13 (0.500) 11 (0.438) 1070 (42) 1070 (42) 14 (0.563) 13 (0.500) 13 (0.500) 13 (0.500) 1220 (4e) 1220 (48) 16 (0.625) 14 (0.563) 16 (0.625) 14 (0.563) 1370 (54) 1370 (54) 17 (0.688) 16 (0.625) 16 (0.625) 16 (0.625) 1520 (60) 1520 (60) 19 (0.750) 17 (0.688) 16 (0.625) 16 (0.625) 1680 (66) 1680 (66) 20 (0.813) 19 (0.750) 16 (0.625) 16 (0.625) 1830 (72) 1830 (72) 22 (0.e75) 20 (0.813) 19 (0.750) 19 (0.750) Note: Recommended minimum thicknesses are for a 1.4-m (4.5-ft) ground cover. Table 8.2 Table 8-3 Typical Pushing Requirements for Concrete Pipe Cohesion of Various Soils Sandy Soil Hard Soil Pipe No Excavation Excavation OD at Face at Face mm (in.) kN (tons) kN (tons) 50 (18) 8.90 (1.0) 3.56 (0.40) 610 (24) 12.45 (1.4) 4.63 0.52) 760 (30) 17.79 (2.0) 6.76 (0.76) 910 (36) 17.79 (2.0) 6.76 (0.76) 1070 (42) 20.46 (2.3) 7.83 (0.88) 1220 (48) 24.02 (2.7) 8.90 (1.0) 1370 (54) 26.69 (3.0) 9.79 (1.1) 1520 (60) 29.36 (3.3) 10.68 (1.2) 1680 (66) 32.03 (3.6) 12.45 (1.4) 1830 (72) 34.69 (3.9) 13.34 (1.5) 1980 (78) 38.25 (4.3) 14.23 (1.6) 2130 (84) 40.92 (4.6) 15.12 (1.7) 2290 (90) 43.59 (4.9) 16.01 (1.8) 2440 (96) 46.26 (5.2) 16.90 (1.9) 2740 (108) 55.16 (6.2) 20.46 (2.3) From: Horizontal Earth Boring and Pipe Jacking Manual No. 2, National Utility Contractors Association, Arlington, VA. Material Cohesion, Wm` (psi) Clay Son 1,915 (40) Medium 11,970 (250) Hard 47,980 (1,000) Sand Loose Dry 0 (0) Silty 4,788 (100) Dense 14,364 (300) Topsoil Saturated 4,788 (100) wt=CtwB'2-2cCtLit (8-1) C. Earth load. Equation 8-2 is used to calculate the load the casing pipe needs to support. It includes the effects of cohesion in the overburden soil. 8-3 EM 1110-2-2902 31 Oct 97 Cr = 1 -[e I/a 2 Kµ' H I '�� (8-2) 2 Kp' where Wr = earth load under tunneled or jacked conditions, N/m (lbf/ft) Cr = load coefficient for tunneled or jacked pipe 8-4 W = unit weight of soil, N/m3 (pcf) Br = maximum width of bore excavation, in (ft) c = cohesion of soil above the excavation, N/mZ (psf) (Table 8-3) Kp' = 0.165 (sand/gravel), 0.150 (saturated top soil), 0.130 (clay), and 0.110 (saturated clay) H = height of fill, in (ft) Appendix A References A-1. Required Publications EM 1110-2-1603 Hydraulic Design of Spillways EM 1110.2-1913 Design and Construction of Levees EM 1110.2-2102 Waterstops and Other Joint Materials EM 1110-2-2104 Strength Design for Reinforced -Concrete Hydraulic Structures EM 1110-2-2400 Structural Design of Spillways and Outlet Works EM 1110-2-2901 Tunnels and Shafts in Rock Note: Specifications are grouped by issuing agency and then arranged in numerical order by specification designation. American Association of State Highway & Transporta- tion Officials (AASHTO) 1996 American Association of State Highway & Transportation Officials. 1996. Standard Specifications for Highway Bridges, Sixteenth Edition, Washington, DC. American Association of State Highway & Transpor- tation Officials (AASHTO) American Association of State Highway & Transportation Officials, M36/M36M, Standard Specification for Corru- gated Steel Pipe, Metallic -Coated, for Sewers and Drains, Washington, DC. American Association of State Highway & Transpor- tation Officials (AASHTO) American Association of State Highway & Transportation Officials, MI70/M170M, Standard Specification for Rein- forced Concrete Culvert, Storm Drain, and Sewer Pipe, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M190, Standard Specification for Bituminous EM 1110-2-2902 31 Oct 97 Coated Corrugated Metal Culvert Pipe and Pipe Aches, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M1961M196M, Standard Specification for Cor- rugated Aluminum Pipe for Sewers and Drains, Washing- ton, DC. American Association of State Highway & Transporta. tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M206/M206M. Standard Specification for Rein- forced Concrete Arch Culvert Storm Drain and Sewer Pipe, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M207/M207M, Standard Specification for Rein- forced Concrete Elliptical Culvert, Storm Drain and Sewer Pipe, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway 6t Transportation Officials, M218, Standard Specification for Steel Sheet, Zinc -Coated (Galvanized) for Corrugated Steel Pipe, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M242/M242M, Standard Specif eation for Rein- forced Concrete D-Load Culvert, Storm Drain, and Sewer Pipe, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M245/M245M, Interim Specification for Corru- gated Steel Pipe, Polymer Precoated for Sewers and Drains, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M246/M246M, Standard specifications for Steel Sheet, Metallic -Coated and Polymer Pre coated for Corru- gated Steel Pipe, Washington, DC. A-1 EM 1110-2-2902 Change 1 31 Mar 98 American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M259IM259M, Standard Specification for Pre- cast Reinforced Concrete Box Sections for Culverts, Storm Drains, and Sewers, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M273IM273M, Standard Specification for Pre- cast Reinforced Concrete Box Sections for Culverts, Storm Drains, and Sewers with less than 2 ft (0.6 m) of Cover Subjected to Highway Loadings, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M274, Steel Sheet Aluminum -Coated (Type 2) for Corrugated Steel Pipe, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M278IM278M, Standard Specification for Class PS 50 Polyvinyl Chloride (PVC) Pipe, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, M294, Standard Specification for Corrugated Polyethylene Pipe 12 in. to 36 in. Diameter, Washington, DC. American Association of State Highway & Transportation Officials (AASHTO) American Association of State Highway & Transportation Officials, M304, Poly (Vinyl Chloride) (PVC) Profile Wall Drain Pipe and Fittings Based on Controlled Inside Diameter, Washington, DC. American Association of State Highway & Transporta- tion Officials (AASHTO) American Association of State Highway & Transportation Officials, T99, Standard Method of Test for the Moisture -Density Relations of Soils Using a 5.5 lb (2.5 kg) Rammer and a 12 in. (305 mm) Drop, Washington, DC. American Concrete Institute American Concrete Institute, Building Code Requirements for Reinforced Concrete (ACI318), Detroit, MI. A-2 American Concrete Pipe Association 1992 American Concrete Pipe Association. 1992. Concrete Pipe Design Manual, Vienna, VA. American Iron and Steel Institute 1993 American Iron and Steel Institute. 1993. Handbook of Steel Drainage and Highway Construction Products, Washington, DC. American Iron and Steel Institute 1989 American Iron and Steel Institute. 1989. Welded Steel Pipe --Steel Plate Engineering Data, Volume 3, Washing- ton, DC. American Railway Engineering Association (AREA) 1996 American Railway Engineering Association (AREA). 1996. AREA Manual, Washington, DC. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A307, Stan- dard Specification for Carbon Steel Bolts and Studs, 60,000 Psi Tensile Strength, Philadelphia, P.A. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A6191 A619M, Standard Specification for Steel, Sheet, Carbon, Cold -Rolled, Drawing Quality, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A7421 A742M, Standard Specification for Steel Sheet, Metallic Coated and Polymer Precoated for Corrugated Steel Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A746, Stan- dard Specification for Ductile Iron Gravity Sewer Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A7601 A760M, Standard Specification for Corrugated Steel Pipe. Metallic -Coated for Sewers and Drains, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A7621 A762M, Standard Specification for Corrugated Steel Pipe, Polymer Precoated for Sewers and Drains, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A7961 A796M Standard Practice for Structural Design of Corru- gated Steel Pipe, Pipe -Arches, and Arches for Storm and Sanitary Sewers and Other Buried Applications, Phila- delphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A798, Stan- dard Practice for Installing Factory -Made Corrugated Steel Pipe for Sewers and Other Applications, Philadel- phia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A807, Stan- dard Practice for Installing Corrugated Steel Structural Plate Pipe for Sewers and Other Applications, Philadel- phia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A8491 A849M, Standard Specification for Post Applied Coatings, Pavings, and Linings for Corrugated Steel Sewer and Drainage Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A8851 A885M, Standard Specification for Steel Sheet, Zinc and Around Fiber Composite Coated for Corrugated Steel Sewer, Culvert, and Underdrain Pipe, Philadelphia, PA. * American Society for Testing and Materials (ASTM) American Society for Testing and Materials, A9291 A929M, Standard Specification for Steel Sheet, Metallic - Coated by the Hot -Dip Process for Corrugated Steel Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, B7441 B744M, Standard Specification for Aluminum Alloy Sheet for Corrugated Aluminum Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, B7451 B745M, Standard Specification for Corrugated Aluminum Pipe for Sewers and Drains, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, B788, Stan- dard Practice for Installing Factory -Made Corrugated Aluminum Culverts and Storm Sewer Pipe, Philadelphia, PA. EM 1110-2-2902 Change 1 31 Mar 98 American Society for Testing and Materials (ASTM) American Society for Testing and Materials, B789, Stan- dard Practice for Installing Corrugated Aluminum Struc- tural Plate Pipe for_Culverts and Sewers, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, B790, Stan- dard Practice for Structural Design of Corrugated Alumi- num Pipe, Pipe -Arches and Arches for Culverts, Storm Sewers, and Buried Conduits, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials. C761C76M, Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials. C78IC78M, Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with triple -Point Loading), Philadel- phia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C3611 C361M, Standard Specification for Reinforced Concrete Low -Head Pressure Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C4431 C443M Standard Specification for Joints ,for Circular Concrete Sewer and Culvert Pipe Using Rubber Gaskets, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C4971 C497M, Standard Test methods for Concrete Pipe, Man- hole Sections, or Tile, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C50& C506M, Standard Specification for Reinforced Concrete Arch Culvert, Storm Drain, and Sewer Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C5071 C507M, Standard Specification for Reinforced Concrete Elliptical Culvert, Storm Drain, and Sewer Pipe, Philadel- phia, PA. A-3 EM 1110-2-2902 31 Oct 97 American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C6551 C655M, Standard Specification for Reinforced Concrete D-Load Culvert, Storm Drain, and Sewer Pipe, Philadel- phia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C7891 C789M, Standard Specification for Precast Reinforced Concrete Box Sections for Culverts, Storm Drains, and Sewers, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C8501 C850M, Standard Specification for Precast Reinforced Concrete Box Sections for Culverts, Storm Drains, and Sewers with less than 2 ft (0.6 m) of Cover subjected to Highway Loadings, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C857/ C857M, Standard Practice for Minimum Structural Design Loading for Underground Precast Concrete Utility Struc- tures, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C8771 C877M, Standard Specification for External Sealing Bands for Noncircular Concrete Sewer, Storm Drain, and Culvert Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C900, Stan- dard Test Method for Pullout Strength of Hardened Con- crete, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C9241 C924M, Standard Practice for Testing Concrete Pipe Sewer Lines by Low -Pressure Air Test Method, Philadel- phia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C9691 C969M, Standard Practice for Infiltration and Exfiltration Acceptance Testing of Installed Precast Concrete Pipe Sewer Lines, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C11031 C1103M, Standard Practice for Joint Acceptance Testing of Installed Precast Concrete Pipe sewer Lines, Philadel- phia, PA. A-4 American Society for Testing and Materials (ASTM) American Society for Testing and Materials, C12141 C1214M, Testing Concrete Pipe Sewerlines by Negative Air Pressure, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D698, Test Method for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,000 ft-Ibf/h,3) (600 kN- m1m3), Philadelphia, PA. Amhrican Society for Testing and Materials (ASTM) American Society for Testing and Materials, D1056, Standard Specification for Flexible Cellular Materials - Sponge or Expanded Rubber, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D1754, Standard Test Method for Effect of Heat and Air on Asphaltic Materials, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D1784, Standard Specification for Rigid Poly0myl) Chloride) (PVC) Compounds and Chlorinated PolyVinyl Chloride) CPVC) Compounds, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D2262, Standard Test Method for Tearing Strength of Woven Fabrics by the Tongue (Single Rip) Method (Constant Rate of Traverse Tensile Testing Machine), Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D2321, Standard Practice for Underground Installation of Ther- moplastic Pipe for Sewers and Other Gravity -Flaw Appli- cation, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D2412, Standard Test Method for Determination of External Loading Characteristics of Plastic Pipe by Parallel -Plate Loading, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D2487-93, Standard Classification of Soils for Engineering Purposes (Unified Soil Classification System), Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D2680, Standard Specification for Acrylonitrile- Butadiene-Styrene (ABS) and Poly(Vinyl Chloride) (PVC) Composite Sewer Piping, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D3034, Standard Specification for Type PSM Poly(Vinyl Chloride) (PVC) Sewer Pipe and Fittings, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D3212, Standard Specification for Joint for Drain and Sewer Plastic Pipes Using Flexible Elastomeric Seals, Philadel- phia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D3262, Standard Specification for 'Fiberglass' (Glass -Fiber - Reinforced Thermosetting Resin) Sewer Pipe, Philadel- phia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D3350, Standard Specification for Polyethylene Plastics Pipe and Fittings Materials, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D3550, Standard Practice far Ring -Lines Barrel Sampling of Soils, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D3839, Standard Practice for Underground Installation of Fiber- glass' (Glass Fiber Reinforced Thermosetting Resin) Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D3919, Standard Practice for Measuring Trace Elements in Water by Graphite Furnace Atomic Absorption Spectrophotome- try, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D4253, Standard Test Method for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table, Philadelphia, PA. EM 1110-2-2902 31 Oct 97 American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D4254, Standard Test Method for Minimum Index Density and Unit Weight of Soils and Calculation of Re!ative Density, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, D4161, Standard Specification for 'Fiberglass' (Glass Fiber -Reinforced Thermosetting Resin) A& Joints Using Flexible Elastomeric Seals, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, F667, Large Diameter Corrugated Polyethylene Tubing and Fittings, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, F679, Standard Specification for Poly(Vinyl Chloride) (PVC) Large -Diameter Plastic Gravity Sewer Pipe and Fittings, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, F714, Standard Specification for Polyethylene (I'E,I Plastic Pipe (SDR-PR) Based on Outside Diameter, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, F794, Standard Specification for Poly(Vinyl) Chloride) (PVC) Profile Gravity Sewer Pipe and Fittings Based on Controlled Inside Diameter, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, F894, Standard Specification for Polyethylene (PE) Large Diameter Profile Wall Sewer and Drain Pipe, Philadelphia, PA. American Society for Testing and Materials (ASTM) American Society for Testing and Materials, F949, Standard Specification for Poly(Vnyl Chloride) (PVC) Corrugate Sewer Pipe with a Smooth Interior and Fittings, Philadelphia, PA. American Water Works Association 1985 American Water Works Association. 1985. AWWA M11, Steel Pipe --A Guide for Design and Installation, Denver, CO. A-5 EM 1110-2-2902 31 Oct 97 American Water Works Association 1989 American Water Works Association. 1989. AWWA C 300, Standard for Reinforced Concrete Pressure Pipe, Steel Cylinder Type, for Water and Other Liquids, Denver, CO. American Water Works Association 1992 American Water Works Association. 1992. AWWA C 301, Standard for Prestressed Concrete Pressure Pipe, Steel Cylinder Type, for Water and Other Liquids, Denver, CO. American Water Works Association 1987 American Water Works Association. 1987. AWWA C 302, Standard for Reinforced Concrete Pressure Pipe, Noncylinder Type, for Water and Other Liquids, Denver, CO. American Water Works Association 1992 American Water Works Association. 1992. AWWA C 304, Design of Prestressed Concrete Cylinder Pipe, Denver, CO. American Water Works Association American Water Works Association. AWWA C 950, Standard for Glass Fiber Reinforced Thermosetting Resin Pressure Pipe, Denver, CO. American Water Works Association American Water Works Association, C1101A21.10, Amer- ican National Standard for Ductile -Iron and Grey -Iron Fittings 3 in. through 48 in. (75 mm through 1200 mot), for Water and Other Liquids, Denver, CO, 80235 American Water Works Association American Water Works Association, C1151A21.15, Amer- ican National Standard for Flanged Ductile -Iron Pipe with Threaded Flanges, Denver, CO, 80235 American Water Works Association American Water Works Association, C1501A21.50, Amer- ican National Standard for the Thickness Design of Duc- tile Iron Pipe, Denver, CO. A-2. Related Publications EM 1110-2-2105 Design of Hydraulic Steel Structures EM 1110-2-3104 Structural and Architectural Design of Pump Stations A-6 Abbett 1956 Abbett, Robert W., ed. 1956. American Civil Engineering Practice, Vol II, Wiley, New York, NY, pp 18-64 and 19-08. American Concrete Pipe Association 1988 American Concrete Pipe Association. 1986. Concrete Pipe Handbook, Vienna, VA. American Concrete Pipe Association 1993 American Concrete Pipe Association. 1993. Concrete Technology Handbook, Vienna, VA. American Society of Civil Engineers (ASCE) 1975 American Society for Civil Engineers (ASCE). 1975. Pipeline Design for Hydrocarbon Gases .and Liquids, New York, NY. American Society of Civil Engineers (ASCE) 1984 American Society for Civil Engineers (ASCE). 1984, Pipeline Materials and Design, New York, NY. American Society of Civil Engineers (ASCE) 1990 American Society for Civil Engineers (ASCE). 1990. Pipeline Design and Installation, New York, NY. American Society of Civil Engineers (ASCE) 1992 American Society for Civil Engineers (ASCE). 1992. Standard Practice for Direct Design of Buried Concrete Pipe Using Standard Installations, New York, NY. American Society of Civil Engineers (ASCE) 1993 American Society for Civil Engineers (ASCE). 1993. Steel Penstocks, ASCE Manual Report or! Engineering Practice, No. 79, New York, NY. Civil Engineering Research Foundation 1992 Civil Engineering Research Foundation. 1992. "Current State of Life Cycle Design for Local Protection Struc- tures, A Literature Search," Washington, DC. Howard 1977 Howard, Amster K. 1977, Modulus of Soil Reaction (E') Values for Buried Flexible Pipe, Journal of the Geotech- nicol Engineering Division, American Society of Civil Engineers, Vol 103(G7), Proceedings Paper 12700. Krynine 1938 Krynine, D. P. 1938. Pressures Beneath a Spread Founda- tion, Transactions, American Society of Civil Engineers (ASCE), New York, NY. EM 1110-2-2902 31 Oct 97 Leonards 1962 Rowe 1957 Leonards, G. A., ed. 1962. Foundation Engineering, Rowe, R. R. 1957. Rigid Culverts Under High Overfills, McGraw-Hill, New York, NY. Transactions, American Society of Civil Engineers (ASCE), New York, NY. Metcalf and Eddy 1928 Metcalf, L. and Eddy, H. P. 1928. American Sewerage Practice, Vol 1, Second Edition, McGraw-Hill, New York, NY. National Utility Contractors Association National Utility Contractors Association. Horizontal Earth Boring and Pipe Jacking Manual No. 2, Arlington, VA. Newmark 1942 Newmark, Nathan M. 1942. Influence Charts for Compu- tation of Stresses in Elastic Foundations. University of Illinois Bulletin Series, No. 338, Urbana, IL. Portland Cement Association 1975 Portland Cement Association. 1975. Concrete Culverts and Conduits, Skokie, IL. Roark 1989 Roark, R. J. 1989. Formulas for Stress and Strain, McGraw-Hill, New York, NY. Spangler 1948 Spangler, M. G. 1948. Underground. Conduits --An Appraisal of Modern Research, Transactions, American Society of Civil Engineers (ASCE), New York, NY, p 316. Szechy 1973 Szechy, K. 1973. The Art of Tunneling, Hungarian Aca- demy of Sciences, Budapest, Hungary. Water Pollution Control Federation 1974 Water Pollution Control Federation. 1974. Design and Construction of Sanitary and Storm Sewers, Manual of Practice, No. 9. (American Society of Civil Engineers (ASCE) Manual of Engineering Practice, No. 37.), New York, NY. A-7 Appendix B Design Examples Design examples for conduits, culverts, and pipes are presented in this appendix. Each equation in this manual is used in the order presented in its chapter. Once a variable is defined, that value is used throughout the remaining calculations. The design method for corrugated EM 1110-2-2902 31 Oct 97 metal pipe from ASTM A 796 is included for Chapter 4. This method also applies to corrugated aluminum pipe using the ASTM B 790 method of design. At the end of this appendix is a demonstration of a finite element method computer code used to analyze concrete rectangular and oblong shapes. B-1 EM 1110-2-2902 31 Oct 97 Chapter 2: Cast -in -Place Conduits for Dams Prism Loads Unit Weight of Soil, Water, and Saturated Soil yf = 21,210 N/m3 (135 pcf) - Saturated soil yd = 18,850 N/m3 (120 pcf) - Dry soil yw = 9,800 N/m3 (62.5 pcf) - Water Height of Soil, Water and Saturated Soil above the Crown of the Conduit. Hd = 2.44 m (8 ft) - Dry soil column Hw = 15.24 m (50 ft) - Water column HS = 6.10 m (20 ft) - Saturated column Vertical Pressures Vertical pressures for the given soil condition; dry soil, dry and saturated soil, or reservoir condition (saturated soil under water). Wwl = Yd ' Hd or Ww2=Yd'Hd+II, 'Hs or Ww3 = T. ' Hw + (Y ,s - Y.) ' Hr Wwt = 45,994 N/m2 (960 psf) Ww2 = 1,753,754 N/m2 (3,660 psf) Ww3 = 218,953 N/m2 (4,572 psf) Internal Water Pressure N/m2 (psf) N/m2 (psf) N/m2 (psf) (2-1) Dry (2-1) Dry and saturated (2-1) Reservoir HG = 36.6 m (120 ft) - Hydraulic gradient r + 1.22 m (4 ft) - Internal radius of conduit (+ or -) depending on the position of interest - top or bottom of the conduit wt = 1K, • (Hg + r) N/m2 (psf) w, = 370,636 N/m2 (7,738 psf) B-2 EM 1110-2-2902 31 Oct 97 Concentrated Live Loads Vertical Pressure P = 44,480 N (10,000 lb) y = 0.305 m (1 ft) - Y - Cartesian coordinate z = 0.610 m (2 ft) - Z - Cartesian coordinate x = 0.915 m (3 ft) - X- Cartesian coordinate R = x2 + zz + y2 m (ft) - Radial distance from point load R = 1.141 m (3.742 ft) 3 W,, = 3 • P • z N/m2 (psf) - Vertical pressure from a concentrated load 2 •t< - R' w, = 2,490 N/mZ (52 psf) Horizontal Pressure r = 0.610 m (2 ft) - Surface radius from point load µ = 0.3 Poisson's ratio: 0.5 for saturated cohesive soils, 0.2 to 0.3 for other soils Pr - P 3 • r2 • z (I - 2 • µ) Nsm (psf) 22 • t<� R5 - (R + z) R� PC = 1,074 N/m2 (23 psf) Trench Backfili Loads Trench with No Superimposed Fill, Condition 1 Vertical Trench Load Values for Ku and g are KY = 0.15 Granular w/o cohesion KW = 0.1924, g = 15,700 N/m3 (100 pcf) H = 2.44 m (8 ft) Sand and gravel 18,850 (120) 0.165 Saturated topsoil 17,280 (I10) 150 Ordinary clay 15,710 (100) 0.130 Bd = 1.52 m (5 ft) Saturated clay 20,420 (130) 0.110 Maximum design load 22,000 (140) 0.110 (2-3) (2-4) B-3 EM 1110-2-2902 31 Oct 97 1 - expl L -2 • Kpi • B 1 Cd = d Trench coefficient 2 • Kµ cd = 1.274 Dimensionless Bc=1.22m(4ft) Wel = Cd • yd • Bd N/m (lbf/ft) Or We2 = Yd'Bc -H N/m (lbf/ft) Wel = 55,483 N/m (3,812 lbf/ft) We2 = 56,113 N/m (3,840 Ibf/ft) Horizontal Trench Pressure 0 = 30 ° = Internal friction angle in degrees H=6.1m(20ft) yd = 18,850 N/m3 (120 pcf) for dry soil r Pet=Yd'H•2f tan2r450 - N/m2 (psf) Pet = 38,828 NLL/m2 (800 psf) Trench with Superimposed Fill, Condition II Vertical Trench Load (2-7) (2-5) (2-6) (2-8) Hf= 3 m (10 ft) - Height of superimposed fill above the top of the trench Hh = 1.5 m (5 ft) - Height of effective fill in trench HP = 1.2 m (4 ft) - Height of projected conduit above the natural ground Ww3 = Cd ' Yd ' Bd + ( Hf •' 1.5 • Yd • Bc • Hh - Cd • Yd • Bd ) N/m (Ibf/ft) (2-9) He + HP) or We4 = yd • B, • Hh + ( Hf J • (1.5 • Yd • Bc • Hh - Yd ' Bc • Hh) N/m (Ibf/ft) (2-10) IHc+HP B-4 Wei = 53,946 N/m (3,724 Ibf/ft) We4 = 41,584 N/m (2,900 lbf/ft) Horizontal Trench Pressure r Pea = Y ' Hh • I tang (45 deg - J . f LL l 2)J qeH • 10.5 • Y ' Hh - Y ' Hh • rtan2(45 • deg - z Pea = 11,362 N/m (242 Ibf/ft) Embankment Condition III Vertical Loads in Wm (Ibf/ft) using yd = 18,850 Wm3 (120 pcf) dry soil: Case 1: We5 = 1.5 ' Yd ' Bc ' He Case 2: We6 = Yd 'Bc • He Vertical Loads in N/m2 (psf) Case 1: We7 = 1.5 ' Yd ' He Case 2: We8 = Yd • He We5 = 210,423 N/m (14,400 lbf/ft) We6 = 140,282 N/m (9,600 Ibf/ft) We7 = 172,478 N/m2 (3,600 psf) We8 = 114,985 N/m2 (2,400 psf) Horizontal Loads in N/m2 (psf) Case 1: Pea = 0.5 • Yd • H,. N/m2 (psf) Case 2: Pe5 = Yd ' H, N/m2 (1,200 psf) Pe4 = 57,493 N/m2 (1,200 psf) Pe5 = 114,985 N/m2 (2,400 psf) EM 1110-2-2902 31 Oct 97 (2-11) (2-12) (2-13) (2-14) (2-15) (2-16) (2-17) B-5 EM 1110-2-2902 31 Oct 97 Notes on Loading Conditions for Embanionents Case 1: pd we = 0.3 and ka = 0.50 Case 2: pl we = 1.00 and ka = 1.00 B-6 E3 EM 1110-2.2902 Change 1 31 Mar 98 Chapter 3: Circular Precast Concrete Pipe for Small Dams and Major Levees D-Load Analysis Load Factor for Trench Condition Bedding Type Load Factor Ordinary 1.5 First Class 1.9 Concrete Cradle 2.5 Load Factors for Embankment Condition Projection Ratio P 0.0 0.3 0.5 0.7 0.9 1.0 X = 0.811 X, = 0.505 B = 1.431 ! ( l X -I 3J Concrete Cradle Xa 0.150 0.743 0.856 0.811 0.678 0.638 Type of Bedding XP Impermissible 1.310 Ordinary 0.840 First Class 0.707 Concrete Cradle 0.505 B!= 6.098 W, = 145,940 N/m (10,000 plf) W = 175,130 N/m (12,000 plf) H!= 1.3 Factor of Safety S; = 1,200 mm (411) ASTM C76 Class and Do of Class Doo] 1 40 (800) II 50 (1,000) III 65 (1,350) IV 100 (2,000) V 140 (3,000) Other Projection Bedding 0.000 0.217 0.423 0.594 0.655 0.638 (3-1) B-7 EM 1110-2.2902 Change 1 31 Mar 98 W, H, W,(HQ Dr?ha= B(Ij • -x= B�(S)(3.2) Do o, = 57 N/m/mm (1,172 plf/ft) ASTM C76M Class III B-8 Chapter 4: Corrugated Metal Pipe for Rural Levees Design In accordance with ASTM A 796 or ASTM B 790 Earth Load (EL) H=3m(1Oft) w = 18,850 N/mz (120 pcf) EL = H • w N/mz (psf) EL = 56,550 N/m2 (1,220 psf) Live Load (LL) Live Loads Under Highways and Railroads Height of Cover, m (ft) Highway, N/m2 (psf) Railroad. N/mz (psf) 0.3 (1) 86,180 (1,800) 0.6(2) 38,300 (800) 181,940 (3,800) 0.9(3) 28,730 (600) 1.2(4) I9,150 (400) 1.5 (5) 11,970 (250) 114,910 (2,400) 1.8 (6) 9,580 (200) 2.1 (7) 8,380 (175) 2.4(8) 4,790 (100) 76,610 (1,600) 3.0(10) 52,670 (1,100) 3.7 (12) 38,300 (800) 4.6(15) 28,730 (600) 6.1 (20) 14,360 (300) 9.1 (30) 4,790 (100) LL = 38,200 N/m2 (800 pst) Live load includes impact P = EL + LL N/m2 (psf) P = 94,850 N/m2 (2,000) psf) - Total load on conduit EM 1110-2-2902 31 Oct 97 B-9 EM 1110-2-2902 31 Oct 97 Required Wall Area S = 1.2 m (4 it) - Span of conduit T = (F 2 S) Thrust per length of conduit T = 56,910 N/m (4,000 lbf/ft) - Thrust per length of conduit SF = 2 Factor of Safety fy = 227,530,000 N/mz (33,000 psi) - Steel yield strength A = T • SF •1000 mmz/mm (in.z/ft) Required area of wall Jy A = OM2 mmz/mm (0.2424 in Z/ft) - Required area of wall Critical Buckling Stress k = 0.22 Soil stiffness factor for granular side fill material E = 2 • 1011 N/mz (29,000,000 psi) Modulus of elasticity of steel fu = 3.10 • 10 N/mz (45,000 psi) Ultimate strength of metal r = 4.3713 ram (0.1721 in.) Radius of gyration (from ASTM) s = 1,220 mm (48 in.) Conduit span z Jc1 = Ju — f° Buckling strength of conduit wag 48•E ( k s z r ) or 12•E _ Jc2 K_ 22 r fc = ifs< k •F .Jc1 Jc2J fc = 2.72 • 10s N/mz (39,523 psi) - This value is greater than the yield strength of the material; therefore, the wall area calculated is adequate. If this value were less than the yield strength then the wall area would need to be recalculated with the lesser value. B-10 EM 1110-2-2902 31 Oct 97 Required Seam Strength SF, = 3 Safety factor for seams SS = T • SF, Required seam strength in Win (Ibf/ft) SS = 170,730 N/m2 (12,000 Ibf/ft) - Check values with tables in ASTM A 796 or ASTM B 790 Handling and Installation Strength - 39,198 mm4/mm (2.392 in 4/ft) - Moment in Inertia of the section selected from the ASTM FF = S 2 . 1,000,000 mm/N (FF/106 in.Ab) E •! FF = 0.00019 mm/N (0.00003 in.Abf) - Flexibility factor shall not exceed the value in the ASTM Flexibility Factors Trench Embankment Depth of Corrugation, mm (in.) FF, mm/N (in./lb) FF mm/N (in.lb) 6 (1/4) 0.255 (0.043) 0.255 (0.043) 13 (1/2) 0.343 (0.060) 0.255 (0.043) 25 (1) 0.343 (0,060) 0.188 (0.033) 50 (2 (round pipe)) 0.114 (0,020) 0.114 (0.020) 50 (2 (arch)) 0.171 (0.030) 140 (5-I/2 (round)) 0.114 (0.020) 0.114 (0.020) 140 (5-1/2 (arch)) 0.171 (0.030) Minimum Cover Design d = 13 mm (1/2 in.) - Depth of corrugations AL = 142,340 N (32,000 lb) - Maximum highway axle load Highway Loadings Class Maximum Axle load. N Ob) H 20 142,340 (32,000) HS 20 I42,340 (32,000) H 15 106,760 (24,000) HS 15 106,760 (24,000) B-11 EM 1110-2-2902 31 Oct 97 H�a = if 0.23 < if 0.45 > 0.55 • S E d 8 AE d 4 AE d Hmia = 0.3 m (t ft) - minimum cover for highway loads and is never less than 0.3 m (1 ft) Check the requirements for railroad and aircraft loads. Pipe -Arch Bearing Design Maximum height of fill over arch pipe assuming 191,520 N/mz (2 tsi) bearing capacity for the soil r, = 0.46 m (1.5 ft) - corner radius of pipe -arch 66.7 • r Hmx = ` S • 0.3048 m (Hmax/0.3048 = ft) Maximum cover H=x = 7.79 m (25 ft) B-12 EM 1110-2-2902 31 Oct 97 Chapter 5: Culverts Use the same design procedure as developed in Chapter 3 for precast pipe. Use the bedding load factors as defined in American Concrete Pipe Association Concrete Pipe Design Manual (1992). Circular Concrete Culvert, Class B Bedding, Embankment Condition B = CA (5-1) i CN _ xq CA = 1.431 CN = 0.707 x = 0.594 A = 0.33 P=0.7 C,=3 H=8 BC=4 ft E = 0.50 q = C� B + EP� 50.33 q _ 0.33(0.7) (2 + 0.5(0.7)) = 0,191 2 0.33 (5-2) 3 Bedding factor Bf 1.431 Bf 2.387 [0.707 - 0.594 (0.181)] - D0 01 Calculation WT Hf Do.ol = S Bf Si=B,=4ft Hf= 1.0 Bf= 2.387 WT = 1.5 y Br Hh: y = 120 pcf Hh=8+4=10ft 2 WT = 1.5(120)(4)(10) = 7200 lbf/ft D 7200 (1) = 754 lb 0.01 = 4 (2.387) ftlfr Use Class I, C76 B-13 EM 1110-2-2902 31 Oct 97 Chapter 6: Plastic Pipe for Other Applications Pipe Stiffness D = 0.250 m (10 in.) - Pipe diameter R = � R = 0.125 m (5 in.) - Pipe radius 1 = 8 mm (0.134 5 in.) - Wall thickness F.p = 3.03 • 109 N/m2 (440,000 psi) - Initial modulus of elasticity (plastic) I = 13 • 10-9 m4/m (in 4/in.) Moment of inertia 12 I = 4.27 • 10-8 m4/m (0.0026 in.4in.) 2 FF = D s 1000 < = 0.542 m/N (95 in./Ib) E•I FF = 0.4934 m/N (85 in.lb) PS = E I > = 98,946/D N/m/m (565/D lb/in./in.) 0.149 R3 PS = 444,237 >_ 9 p46 = 395,784 OK Deflection DL = 2.5 Deflection lag factor for long-term prediction K = 0.11 Bedding constant E' = 6.89 • 106 N/m2 (1,000 psi) - Soil modulus P = 69,000 N/m2 (10 psi) - Service pressure at the crown of the pipe 4Y DL•K•P 100 percent D 0.149 • (PS) + 0.061 • (El) AY = 3.90% - Pipe deflection D B-14 (6-1) (6-2) (6-3) EM 1110-2-2902 31 Oct 97 Wall Stress (Crushing) PST = 68,950 N/m2 (1,440 pst) - Short-term pressure at the crown of the conduit PLT = 68,950 N/m2 (1,440 pst) - Long-term pressure at the crown of the conduit f = 3.03 • 109 N/m2 (440,000 psi) Initial tensile strength of the pipe material f5o = 1.09 • 109 N/m2 (158,400 psi) - 50-year tensile strength of the pipe material D = 0.3 m (1 ft) - Diameter of pipe TST = D ' PZTTST = 10,343 N/m (720 lbf/ft) - Short-term wall thrust (64) TLT = D ' P2TTLT = 10,343 N/m (720 Ibf/ft) - Long-term wall thrust (6-5) A 2 2 • TST TLT 106 A = 25.8 mm2/m (0.0124 in 2/ft) - Wall area (6-6) Ai f50 Ring Buckling H = 3 m (10 ft) - Height of soil above the crown of the pipe Ha, = 6 m (20 ft) - Height of water above the crown of the pipe R = 0.3 m (12 in.) - Mean radius h B = 1 - 0.33 � Buoyancy factor B = 0.34 E = 9.65 • 101 N/m2 (140,000 psi) - 50-year Modulus of elasticity MS = 11.72 • I06 N/m2 (1,700 psi) - Soil modulus A = 3,050 mm2/m (1.44 in2/fI) - Wall area ! = 42,610 mm4/m (0.0026 in.4/in.) - Moment of inertia of the wall section fcr = 0.77 • R B • M s E • ! N/m2 (fa* 12 (psi)) -Wall buckling stress (6-7) A 0.149 • R3 B-15 EM 1110-2-2902 31 Oct 97 fcr = faFS = 2 fc = 7.6424 2 Hydrostatic Buckling v = 0.39 Poisson's ration K = 1.5 (10)-12 SI, 216 non-SI 106 N/m2 (1,096 psi) Pc, = C( KEl . 0.7 N/m2 (psf) - Buckling stress (I - v2)R3 C = Ovality = 0.7 for 4 percent deflection Pc, = 1,886 N/m2 (37.3 psf) - Field stress or radial pressure from the water Wall Strain Cracking t. = 6 mm (0.25 in.) - Thickness of pipe wall D = 250 mm (10 in.) - Pipe diameter Ay = 3.9% Ratio of pipe deflection to pipe diameter D 0.03 DY Eb = tmax D mmtmm (inJin.) - Wall strain < strain limit/2 D eb = 0.003 < 0.05/2 = 0.025 OK B-16 (6-8) (6-9) Chapter 7: Ductile Iron Pipe and Steel Pipe for Other Applications Earth Load Limited by: Bending Stress f = 3.31 • 108 N/m' 48,000 psi) - Design stress t = 6 mm (0.25 in.) - Wall thickness D = 250 turn (10 in.) - Pipe diameter E = 165.5 • 109 N/m2 (24.000,000 psi) - Modulus of elasticity E' = 3.45 • 106 N/mZ (500 psi) - Soil modulus DIPRA Type 4 bedding Kb = 0.157 Bending moment coefficient Kx = 0.096 Deflection coefficient D.dD = 0.03 Deflection limit Pv = 2 3[� - �] jKb - Kx 8_t + 0.732 D 1 t Pvj = 458,267 N/m2 (10,279) psf) Deflection PV - (��D� 8E + 0.732 Etx 77M Py2 = 578,439 N/m2 (12,061 psf) EM 1110-2-2902 31 Oct 97 (7-1) (7-2) B-17 EM 1110-2-2902 31 Oct 97 Chapter 8: Pipe Jacking Br = 1.2 m (4 ft) - Diameter of pipe w = 18,850 N/m3 (120 pcf) - Unit weight of soil KM = 0.130 Soil constant H = 15 m (50 ft) - Height of soil c = 4,790 N/m2 (100 psf) - Cohesion ezp -2 ' KN B H (8-2) 2 K Cr = 1 - Load coefficient 11 • C, = 0.8509 Load coefficient Wr = Ct • w • BIZ - 2 • c • C, • Bt N/m (lbf/ft) - Earth load on pipe (8-1) W, = 13,314 N/m (953 lbf/ft) B-18 EM 1110-2-2902 31 Oct 97 Rectangular Condult (Trench) - Cast -In -Place Vertical Pressure , We = 18.9 (3) 11A dinary Damp = 57.6 kPa 0,200 psf) 18.9 kPa 1120 pcf) PeT = 57.6 = 19.2 kPa (400 psf) 3 Pe. = 4.5 m (19.2) = 28.8 kPa 3.0 m (600 psf) ��.��,��u Ws = Welght of Structure BOX kN-m (plf) Next calculate FEWs and dlstrlbute to design sectlon. Use load factors from EM 1110-2-2104. Other Computer programs that can be used to analyze this shaped culvert Include CANDE (Culvert Analysts Design), CORTCUL (Design or Investigation of Orthogonal Culverts) Standard reinforcement for rectangular sectlon Is Included In ASTM C789 and C850. 192 kPa D 19.2 kPa 8.8 (6.5) 8B (6.5) (400 psf) (1200 psf) (400 psf) 8.8 (6.5 8.8 (6.5) C� 9.8 (72J 3. (lOA) 9.8 (72) !32 (9.7) 28B kPa 57.5 kPa 28.8 kPo 122 (9.0) 122 (9.0) (600 psf) (1200 )Sr) (600 psf) 122 (90) 122 (9.0) (WS/U-V) LOADING DIAGRAM MOMENT DIAGRAM kN—m (K—ft) 8-19 EM 1110-2-2902 31 Oct 97 Oblong Condult (Trench) - Cost -In -Place Vertical Pressure We = 18.9 (3) = 57.6 kPa (I,200 psf) Ordinary Damp Clay Per = 57.6 = 19.2 kPa (400 psf) 3 Pet, = IIJ m (192) = 77.0 kPa 3.0 m (I500 psf) W.7 - (Pe r+Pet,) - 45.6 kPa n -50 2 (950 psf) Ws = Welght of Structure kN-m (plf) •189 (120 3 m (l0'-0") OBLONG PIPE Moments and shears for this sectlon were calculated using the computer program STAAD W. Other finite element computer programs work as well. 57.5 kPo 45.6 kPa 45 6 kPa (950 psf) (950 psf) 1Ws 45.6 kPa 45.6 kPa (950 psf) 575 k�° (950 psf) Ws/3m s LOADING DIAGRAM 171W 3J (23) 3J (23) MOMENT DIAGRAM kN-m (K-ft) Appendix C Evaluation and Inspection of Existing Systems This appendix will be completed when data become avail- able in the future. The outline below presents a list of key features that need to be considered when evaluating and inspecting existing systems. C-1. Site Inspection a. Surface settlement. b. Surface water. c. Dip in pavement. d. Settlement of manholes or control structure. C-2. Interior Inspection a. Visual inspection. b. Camera inspection. C. Smoke testing. d. Infiltration. e. Exf[ltration. f. Piping. C-3. Failures a. Leaking joints. b. Separated joints. c. Crushed pipe wall. d. Perforated pipe wall. e. Misaligned pipe sections. f. Root penetration of pipe. g. Material deposition. h. Change in loading condition. EM 1110-2-2902 31 Oct 97 C-1 Appendix D Repair of Existing Systems This appendix will be completed when data become available in the future. The outline below lists some methods to repair existing systems. D-1. Pipe Replacement D-2. Slip Lining EM 1110-2-2902 31 Oct 97 D-3. In -Place Fracturing and Replacement D-4. Concrete Relining D-5. Plastic Relining and Grouting D-6. Jacking Pipe D-1 EM 1110-2-2902 31 Oct 97 Appendix E Metric Conversion Data Sheet Multiply By To obtain Mass kg (force/ 9.806 650 N Quantity Unit Symbol pound- 0.453 592 kilogram length meter m mass (Ibm) (kg, mass) Force mass kilogram kg pound -force 4.448 222 N time second s (lbf Ibf/ft 14.593 903 N/m force newton N = kg m/s2 Torque lb -in. 0.112 985 N-m stress pascal Pa = N/m2 lb-lt 1.355 818 N-m Pressure and Density energy joule J = N-m foot of water 2.988 980 kPa g/cm3 62.427 900 Pet g/Cm3 9.806 650 kN/m3 Metric Conversions kg/cm2 98.066 500 kPa 2 MPa, N/mm Multiply By To Obtain ksi pcf 6.894 757 16.018 460 kg/m3 pcf 157.087 616 N/m3 Area and Volume psf 47.880 260 Pa psi 6.894 757 kPa ft2 0.092 903 m2 it, 0.028 136 847 m3 gal 0.003 785 412 m3 in.2 - 645.160 000 mm2 Section Modulus in.3 16 387.064 mm3 Moment of Inertia in.4 416 231.430 mm4 Length foot (ft) 304.800 millimeters (mm) inch (in.) 25.400 millimeters (mm) E-1 , / f 2007, and creates a new investment option - Certificate of Deposit Account Registry Service or (Cedars) program. Banking officials from El Paseo Bank and Palm Desert National Bank will be at the meeting to make an educational presentation. Staff has been working with the State Board of Equalization on increasing our quarterly sales tax estimates based upon the November 2006" opening of the new Costco and Sams Club. By including these stores in the City quarterly sales tax estimate, the City will receive these sales tax revenues faster. PUBLIC WORKS The October 2006 lunch meeting of the Building Industry Association (BIA) centered on "rainfall intensity and underground retention in La Quinta." The BIA membership in attendance was supportive of the revisions City staff made to date to the Draft Engineering Bulletins and the Draft Developer Engineering Handbook in ddressing the BIA's comments. The BIA membership also brought other minor issues with regard to hydrology. These issues will also be ad ressed by staff. The appeal regarding suitability of an alternate material (5-gauge galvanized metal plate) for an underground retention facility as applied to the Washington Park Development was heard this week. On a vote of 2 to 1, the Appeals Board gave "conceptual" approval of the metal product for use in underground retention applications, provided that the designer could assure isolation from highly corrosive soils and that it could be adequately maintained. The pre -construction meeting for the Madison Avenue pavement rehabilitation was held on October 30, 2006. The contractor is planning on switching two-way traffic to the north bound lanes of Madison Street on November 6, 2006, and starting pavement grinding operations that week. The City is negotiating a contract to reconstruct landscape and retaining wall improvements at the Monticello Development that were impacted by the Jefferson Avenue widening project.