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10-1171 (SFD) Geotechnical InvestigationA CITY OF LA QUINTA BUILDING & SAFETY DEPT. APPROVED FOR CONSTRUCTION OFC 14 MO SLADDEN ENGINEERING DATE ` ►1 BY Soil Engineers and Geologists Buena Park • Palm Desert • Beaumont • Victorville • Hemet GEOTECHNICAL INVESTIGATION PROPOSED CUSTOM RESIDENCE THE MADISON CLUB- LOT 22A LA QUINTA, CALIFORNIA CITY OF LA QUINTA BUILDING & SAFETY DEPT. A PPROVD FOR CONSTRUCTION DATE 8YJ -Prepared By- Sladden Engineering 45090 Golf Center Parkway, Suite F Indio, California 92201 (760) 772-3893 Sladden Engineering *D Sladden Engineering 45090 Golf Center Parkway, Suite F, Indio, California 92201 (760) 863-0713 Fax (760) 863-0847 6782_Stanton Avenue, Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 800 E. Florida Avenue, Hemet, CA 92543 (951) 766-8777 Fax (951) 766-8778 October 22, 2010 Mr. Bob Lothenbach c/o Design Mind Studio, Inc. 75175 Merle Drive, Suite 200 Palm Desert, California 92211 Subject: Geotechnical Investigation Project: Proposed Custom Residence The Madison Club- Lot 22A La Quinta, California Project No. 544-10168 10-10-244 Sladden Engineering is pleased to present the results of our geotechnical investigation for the proposed custom residence to be constructed within The Madison Club development in the City of La Quinta, California. Our services were completed in accordance with our proposal for geotechnical engineering services dated September 8, 2010 and your authorization to proceed with the work. The purpose of our investigation was to explore the subsurface conditions at the site in order to provide recommendations for foundation design and site preparation. Evaluation of environmental issues and hazardous wastes was not included within the scope of services provided. The opinions, recommendations and design criteria presented in this report are based on our field exploration program, laboratory testing and engineering analyses. Based on the results of our investigation, it is our professional opinion that the proposed project is feasible provided the recommendations presented in this report are implemented in the design and carried out through construction. 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 ENGINEERING No. C 4MM a Exp. 93 M12 Matthew J. Cohrt Brett L. Anderson Project Geologist Principal Engineer 4 Cfyl4y`Q 1 g p g �! ►7r ... . 11C0 SER/mc Copies: 6/Addressee Sladden Engineering GEOTECHNICAL INVESTIGATION PROPOSED CUSTOM RESIDENCE THE MADISON CLUB- LOT 22A LA QUINTA, CALIFORNIA October 22, 2010 TABLE OF CONTENTS INTRODUCTION...... .................. ................................................................. PROJECTDESCRIPTION ............................................ --................................................ ....... ........ ........ 1 SCOPEOF SERVICES ............................................ ---- ...... ........... ............................................ ....... . 2 SITECONDITIONS................................................................................................................................. 2 GEOLOGICSETTING .................... ....................................................................... ...................... .... ....... 3 SUBSURFACE CONDITIONS................................................................................................................3 SEISMICITY AND FAULTING..............................................................................................................4 CBC DESIGN PARAMETERS... .............................................................................................................. 5 GEOLOGICHAZARDS...........................................................................................................................5 CONCLUSIONS...................................................................................................................................... 7 EARTHWORKAND GRADING.......................................................................................................... 8 Stripping.................................... ...................................................................... 8 Preparation of Building Areas........................----............................................................................ 8 Compaction....................................................................................................................................... 8 Shrinkage and Subsidence.............................................................................................................. 9 FOUNDATIONS SPREAD FOOTINGS............................................................................................... 9 SLABS-ON-GRADE......................................................................................................................... ......10 SOLUBLESULFATES.............................................................................................................................10 UTILITY TRENCH BACKFILL..............................................................................................................10 EXTERIOR CONCRETE FLATWORK.................................................................................................11 DRAINAGE.............................................................................................................................................11 LIMITATIONS.........................................................................................................................................12 ADDITIONAL SERVICES.....................................................................................................................12 REFERENCES.........................................................................................................................................13 FIGURES - Site Location Map Regional Geologic Map Borehole Location Plan APPENDIX A - Field Exploration APPENDIX B- Laboratory Testing Sladden Engineering October 22, 2010 - 1 - Project No. 544-10168 10-10-244 INTRODUCTION This report presents the results of the geotechnical investigation performed by Sladden Engineering (Sladden) for the proposed custom residence to be constructed on Lot 22A within The Madison Club development in the City of La Quinta, California. The site is located within the NW 1/4 of Section 10, Township 6 South, Range 7 East (SBBM) at approximately 33.66438 north latitude and 116.247830 west longitude. The approximate location of the site is indicated on the Site Location Map (Figure 1). Our investigation was conducted in order to evaluate the engineering properties of the subsurface materials, to evaluate their in -situ characteristics, and to provide engineering recommendations and design criteria for site preparation, foundation design and the design of various site improvements. This study also includes a review of published and unpublished geotechnical and geological literature regarding seismicity at and near the subject site. PROJECT DESCRIPTION Based on our preliminary conversations, it is our understanding that the proposed project will consist of constructing a new custom residence on the lot. Sladden anticipates that the proposed project will also include new concrete flatwork and associated site improvements. For our analyses we expect that the proposed residence will consist of a relatively lightweight one- or two-story, wood -frame structure supported on conventional shallow spread footings and concrete slabs -on -grade. Grading plans and finished floor elevation were not available at the time of this report. However, based on the previous rough grading conducted at the site and documented by Sladden Engineering, we expect that grading will be limited to minor cuts and fills in order to accomplish the desired pad elevations and provide adequate gradients for site drainage. We do not expect the removal and recompaction of foundation bearing soil will be required provided that eh residence falls within the previously rough graded building envelope. Upon completion of precise grading plans, Sladden should be retained in order to ensure that the recommendations presented within in this report are incorporated into the design of the proposed project. Structural foundation loads were not available at the time of this report. Based on our experience with relatively lightweight structures, we expect that isolated column loads will be less than 30 kips and continuous wall loads will be less than 3.0 kips per linear foot. If these assumed loads vary significantly from the actual loads, we should be consulted to verify the applicability of the recommendations provided. Sladden Engineering October 22, 2010 - 2 - Project No. 544-10168 10-10-244 SCOPE OF SERVICES The purpose of our investigation was to determine specific engineering characteristics of the surface and near surface soil in order to develop foundation design criteria and recommendations for site preparation. Exploration of the site was achieved by drilling three (3) exploratory boreholes to depths of approximately 21.5 and 51.5 feet below (existing) ground surface (bgs). Specifically, our site characterization consisted of the following tasks: ■ Site reconnaissance to assess the existing surface conditions on and adjacent to the site. • Advancing three (3) exploratory boreholes to depths of approximately 21.5 and 51.5 feet bgs in order to characterize the subsurface soil conditions. Representative samples of the soil were classified in the field and retained for laboratory testing and engineering analyses. • Performing laboratory testing on selected samples to evaluate their engineering characteristics. ■ Reviewing geologic literature and discussing geologic hazards. • Performing engineering analyses to develop recommendations for foundation design and site preparation. • The preparation of this report summarizing our work at the site. SITE CONDITIONS The site is located on Lot 22A within the Madison Club development in the City of La Quinta, California. The undeveloped lot is formally identified as APN: 767-670-018 and occupies approximately 0.81 acres. The proposed building area was previously rough graded. As such, previous grading has created a relatively flat building area. The site is bounded by vacant land to the north and south, a golf coarse fairway to the immediate west and Ross Avenue to the east. At the time of our investigation, the site was undeveloped and covered in turf. Based on our review of the USGS (1980), the site is situated at an approximate elevation of 5 feet above mean sea level (AMSL). No natural ponding of water or surface seeps were observed at or near the site during our investigation conducted on September 29, 2010. Site drainage appears to be controlled via sheet flow and surface infiltration. Regional drainage is provided by the Whitewater River that is located approximately five (5) miles northeast of the site. Sladden Engineering October 22, 2010 -3- Project No. 544-10168 10-10-244 GEOLOGIC SETTING The project site is located within the Colorado Desert Physiographic Province (also referred to as the Salton Trough) that is characterized as a northwest -southeast trending structural depression extending from the Gulf of California to the Banning Pass. The Salton Trough is dominated by several northwest trending faults, most notably the San Andreas Fault system. The Salton Trough is bounded by the Santa Rosa — San Jacinto Mountains on the southwest, the San Bernardino Mountains on the north, the Little San Bernardino - Chocolate — Orocopia Mountains on the east, and extends through the Imperial Valley into the Gulf of California on the south. A relatively thick sequence (20,000 feet) of sediment have been deposited in the Coachella Valley portion of the Salton Trough from Miocene to present times. These sediments are predominately terrestrial in nature with some lacustrian (lake) and minor marine deposits. The major contributor of these sediments has been the Colorado River. The mountains surrounding the Coachella Valley are composed primarily of Precambrian metamorphic and Mesozoic "granitic" rock. The Salton Trough is an internally draining area with no readily available outlet to Gulf of California and with portions well below sea level (-253' msl). The region is intermittently blocked from the Gulf of California by the damming effects of the Colorado River delta (current elevation +30'msl). Between about 300AD and 1600 AD (to 1700 ?) the Salton Trough has been inundated by the River's water, forming ancient Lake Cahuilla (max. elevation +58' msl). Since that time the floor of the Trough has been repeatedly flooded with other "fresh" water lakes (1849, 1861, and 1891), the most recent and historically long lived being the current Salton Sea (1905). The sole outlet for these waters is evaporation, leaving behind vast amounts of terrestrial sediment materials and evaporite minerals. The site has been mapped by Rogers (1965) to be immediately underlain by undifferentiated Quaternary - age lake deposits and alluvium (Ql-Qal). The regional geologic setting for the site vicinity is presented on the Regional Geologic Map (Figure 2). SUBSURFACE CONDITIONS The subsurface conditions at the site were investigated by drilling three (3) exploratory boreholes to depths of 21.5 and 51.5 feet bgs in order to observe the subsurface soil conditions. The approximate locations of the boreholes are illustrated on the Borehole Location Plan (Figure 3). The boreholes were advanced using a truck -mounted Mobile B-61 drill -rig equipped with 8-inch outside diameter (O.D.) hollow stem augers. A representative of Sladden was on -site to log the materials encountered and retrieve samples for laboratory testing and engineering analysis. During our field investigation, fill soil consisting of silt sand and sandy silt (SM-ML) was encountered to an approximate maximum depth of ten (10) feet bgs. Underlying the fill soil and extending to maximum depths explored, lacustrine and alluvial deposits were encountered. Generally, the underlying earth materials observed within the bores appeared to have adequate strength for the anticipated foundation loads at relatively shallow exploration depths. Detailed descriptions of the subsurface materials encountered are included in Appendix A of this report. Sladden Engineering October 22, 2010 - 4 - Project No. 544-10168 10-10-244 Groundwater was not encountered to a maximum explored depth of 51.5 feet bgs during our field investigation conducted on September 29, 2010. As such, it is our opinion that groundwater should not be a factor during construction of the proposed project. SEISMICITY AND FAULTING The southwestern United States is a tectonically active and structurally complex region, dominated by northwest trending dextral faults. The faults of the region are often part of complex fault systems, composed of numerous subparallel faults which splay or step from main fault traces. Strong seismic shaking could be produced by any of these faults during the design life of the proposed project. We consider the most significant geologic hazard to the project to be the potential for moderate to strong seismic shaking that is likely to occur during the design life of the project. The proposed project is located in the highly seismic Southern California region within the influence of several fault systems that are considered to be active or potentially active. An active fault is defined by the State of California as a "sufficiently active and well defined fault' that has exhibited surface displacement within the Holocene epoch (about the last 11,000 years). A potentially active fault is defined by the State as a fault with a history of movement within Pleistocene time (between 11,000 and 1.6 million years ago). As previously stated, the site has been subjected to strong seismic shaking related to active faults that traverse through the region. Some of the more significant seismic events near the subject site within recent times include: M6.0 North Palm Springs (1986), M6.1 Joshua Tree (1992), M7.3 Landers (1992), M6.2 Big Bear (1992), M7.1 Hector Mine (1999) and M7.2 Baja California (2010). Table 1 lists the closest known potentially active faults that was generated in part using the EQFAULT computer program (Blake, 2000), as modified using the fault parameters from The Revised 2002 California Probabilistic Seismic Hazard Maps (Cao et al, 2003). This table does not identify the probability of reactivation or the on -site effects from earthquakes occurring on any of the other faults in the region. TABLE 1 CLOSEST KNOWN ACTIVE FAULTS Fault Name Distance (Km) Maximum Event San Andreas - Coachella 12.2 7.2 San Andreas - Southern 12.2 7.2 San Andreas - San Bernardino 17.6 7.5 Burnt Mountain 20.4 6.5 Eureka Peak 24.1 6.4 San Jacinto - Anza 30.7 7.2 San Jacinto - Coyote Creek 35.3 6.8 Pinto Mountain 36.3 7.2 Sladden Engineering October 22, 2010 - 5 - Project No. 544-10168 10-10-244 2007 CBC SEISMIC DESIGN PARAMETERS Sladden has reviewed the 2007 California Building Code (CBC) and summarized the current seismic design parameters for the proposed structure. The seismic design category for a structure may be determined in accordance with Section 1613 of the 2007 CBC or ASCE7. According to the 2007 CBC, Site Class D may be used to estimate design seismic loading for the proposed structures. The period of the structures should be less than 1/2 second. This assumption should be verified by the project structural engineer. The 2007 CBC Seismic Design Parameters are summarized below. Occupancy Category (Table 1604.5): II Site Class (Table 1613.5.5): D Ss (Figure 1613.5.1): 1.500g S1 (Figure 1613.5.1): 0.600g Fa (Table 1613.5.3(1)): 1.0 Fv (Table 1613.5.3(2)): 1.5 Sms (Equation 16-37 {Fa X Ss}): 1.500g Sm1 (Equation 16-38 {Fv X S1}): 0.900g SDS (Equation 16-39 (2/3 X Sms}): 1.00Og SD1 (Equation 16-40 {2/3 X Sm1}): 0.600g Seismic Design Category: D GEOLOGIC HAZARDS The subject site is located in. an active seismic zone and will likely experience strong seismic shaking during the design life of the proposed project. In general, the intensity of ground shaking will depend on several factors including: the distance to the earthquake focus, the earthquake magnitude, the response characteristics of the underlying materials, and the quality and type of construction. Geologic hazards and their relationship to the site are discussed below. I. Surface Rupture. Surface rupture is expected to occur along preexisting, known active fault traces. However, surface rupture could potentially splay or step from known active faults or rupture along unidentified traces. Based on our review of Rogers (1965), Jennings (1994), Hart and Bryant (1997), and RCLIS (2010), no known faults are currently mapped on or projecting towards the site. In addition, no signs of active surface faulting were observed during our review of non -stereo digitized photographs of the site and site vicinity (Google, 2010; Terra Server 2002). Finally, no signs of active surface fault rupture or secondary seismic effects (lateral spreading, lurching etc.) were identified on -site during our field investigation. Therefore, it is our opinion that risks associated with primary surface ground rupture should be considered "low". II. Ground Shaking. The site has been subjected to past ground shaking by faults that traverse through the region. Strong seismic shaking from nearby active faults is expected to produce strong seismic shaking during the design life of the proposed project. A probabilistic approach was employed to the estimate the peak ground acceleration (amax) that could be experienced at the site. Based on the USGS Probabilistic Hazard Curves (USGS, 2009) the site could be subjected to ground motions on the order of 0.5293g. The peak ground acceleration at the site is judged to have a 475 year return period and a 10 percent chance of exceedence in 50 years. Sladden Engineering October 22, 2010 - 6 _ Project No. 544-10168 10-10-244 III. Liquefaction. Liquefaction is the process in which loose, saturated granular soil loses strength as a result of cyclic loading. The strength loss is a result of a decrease in granular sand volume and a positive increase in pore pressures. Generally, liquefaction can occur if all of the following conditions apply: liquefaction -susceptible soil, groundwater within a depth of 50 feet or less, and strong seismic shaking. According to the County of Riverside, the site is situated within a "Moderate" liquefaction potential zone (RCLIS, 2010). Based on our review of groundwater maps of the site vicinity (>50 feet bgs; Tyley, 1975), and our experience in the project vicinity, risks associated with liquefaction and liquefaction related hazards should be considered negligible. IV. Tsunamis and Seiches. Because the site is situated at an inland location, and is not immediately adjacent to any impounded bodies of water, risk associated with tsunamis and seiches is considered negligible. V. Slope Failure Landsliding, Rock Falls. The site is situated on relatively level ground and not situated adjacent to any hillsides. Accordingly, risks associated with slope instability and rock falls hazards are considered "negligible". VI. Expansive Soil. Generally, the site soil consists of silty sand (SM). Based on the results of our laboratory testing (EI=15), the materials underlying the site are considered to have a "very low" expansion potential and the risk of structural damage caused by volumetric changes in the subgrade soil is considered "negligible". VII. Settlement. Settlement resulting from the anticipated foundation loads should be tolerable provided that the recommendations included in this report are considered in foundation design and construction. The estimated ultimate settlement is calculated to be less that approximately one inch when using the recommended bearing values. As a practical matter, differential settlement between footings can be assumed as one-half of the total settlement. VIII. Subsidence. The site situated within a "Susceptible" subsidence zone (RCLIS, 2010). Land subsidence can occur in valleys where aquifer systems have been subjected to extensive groundwater pumping, such that groundwater pumping exceeds groundwater recharge. Generally, pore water reduction can result in a rearrangement of skeletal grains and could result in elastic (recoverable) or inelastic (unrecoverable) deformation of an aquifer system. Recent published literature indicates that the Upper Coachella Valley region between 1996 and 2005 has been subjected to groundwater withdrawal related subsidence (USGS, 2007). Although recent investigations have documented significant subsidence within the La Quinta area (USGS, 2007), no fissures or other surficial evidence of subsidence were observed at the subject site. With the exception of isolated tension zones typically manifested on the ground surface as fissures and/or ground cracks, subsidence related to groundwater depletion is generally areal in nature with limited differential settlement over short distances such as across individual buildings. Sladden Engineering October 22, 2010 - 7 - Project No. 544-10168 10-10-244 The Coachella Valley Water District has publically acknowledged regional subsidence throughout the southern portion of the Coachella Valley and has indicated a commitment to groundwater replenishment programs that are intended' to limit future subsidence. At this time, subsidence is considered a regional problem requiring regional mitigation not specific to the project vicinity. Locally, no fissures or other surficial evidence of subsidence were observed at or near the subject site. However, site specific effects resulting from long term regional subsidence is beyond the scope of our investigation. IX. Debris Flows. Debris flows are viscous flows consisting of poorly sorted mixtures of sediment and water and are generally initiated on slopes steeper than approximately six horizontal to one vertical (6H:1V)(Boggs, 2001). Because the building area is located on elevated topography risks associated with debris flows should be considered remote. X. Flooding and ,Erosion_ No signs of flooding or erosion were observed during our field investigation conducted on September 29, 2010. Accordingly, risks associated with flooding and erosion should be considered low. CONCLUSIONS Based on the results of our investigation, it is our professional opinion that the project is feasible from a soil mechanic's standpoint provided the recommendations of this report are incorporated in the design and carried out through construction. The main geotechnical concern in the construction of the proposed project is the presence of potentially compressible surface soil. The site surface soil is considered loose, potentially compressible and not suitable for support of shallow foundations or concrete slabs in its existing condition. Because of the somewhat loose and potentially compressible condition of the near surface soil, remedial grading including overexcavation or recompaction is recommended for the proposed building and foundation areas. We recommend that remedial grading within the proposed building area include overexcavation and recompaction of the foundation bearing soil. Specific recommendations for site preparation are presented in the Earthwork and Grading section of this report. Caving did occur to varying degrees within each of our exploratory bores and the surface soil may be susceptible to caving within deeper excavations. All excavations should be constructed in accordance with the normal CalOSHA excavation criteria. On the basis of our observations of the materials encountered, we anticipate that the subsoil will conform to that described by CalOSHA as Type B or C. Soil conditions should be verified in the field by a "Competent person" employed by the Contractor. The following recommendations present more detailed design criteria that have been developed on the basis of our field and laboratory investigation. Sladden Engineering October 22, 2010 - 8 - Project No. 544-10168 10-10-244 EARTHWORK AND GRADING All earthwork including excavation, backfill and preparation of the subgrade soil, should be performed in accordance with the geotechnical recommendations presented in this report and portions of the local regulatory requirements, as applicable. All earthwork should be performed under the observation and testing of a qualified soil engineer. The following geotechnical engineering recommendations for the proposed project are based on observations from the field investigation program, laboratory testing and geotechnical engineering analysis. a. Stripping. Areas to be graded should be cleared of any existing structures, vegetation, associated root systems, and debris. All areas scheduled to receive fill should be cleared of old fills and any irreducible matter. The strippings should be removed off site, or stockpiled for later use in landscape areas. Voids left by obstructions should be properly backfilled in accordance with the compaction recommendations of this report. b. Preparation of the Building Areas. Because the lot has been previously rough graded, the remedial grading required at this time should be minimal provided that the building falls within the previously assumed building envelope. The building area should be cleared of surface vegetation, scarified and moisture conditioned prior to precise grading. The exposed surface should be compacted to a minimum of 90 percent relative compaction is attained prior to fill placement. Any fill material should be placed in thin lifts at near optimum moisture content and compacted to at least 90 percent relative compaction. c. Compaction. Soil to be used as engineered fill should be free of organic material, debris, and other deleterious substances, and should not contain irreducible matter greater than three inches in maximum dimension. All fill materials should be placed in thin lifts, not exceeding six inches in their loose state. If import fill is required, the material should be of a low to non -expansive nature and should meet the following criteria: Plastic Index Less than 12 Liquid Limit Less than 35 Percent Soil Passing #200 Sieve Between 15% and 35% Maximum Aggregate Size 3 inches The subgrade and all fills should be compacted with acceptable compaction equipment, to at least 90 percent relative compaction. The bottom of the exposed subgrade should be observed by a representative of Sladden Engineering prior to fill placement. Compaction testing should be performed on all lifts in order to ensure proper placement of the fill materials. Table 2 provides a summary of the excavation and compaction recommendations. Sladden Engineering October 22, 2010 - 9 - Project No. 544-10168 10-10-244 Table 2 SUMMARY OF RECOMMENDATIONS *Remedial Grading Excavation and recompaction within the building envelope and extending laterally for 5 feet beyond the building limits and to a minimum of 3 feet below existing grade or 2 feet below the bottom of the footings, whichever is deeper. Native / Import Engineered Fill Place in thin lifts not exceeding 6 inches in the loose state, compact to a minimum of 90 percent relative compaction within 2 percent of the optimum moisture content. *Actual depth may vary and should be determined by a representative of Sladden Engineering in the field during construction. e. Shrinkage and Subsidence. Volumetric shrinkage of the material that is excavated and replaced as controlled compacted fill should be anticipated. We estimate that this shrinkage could vary from 15 to 25 percent Subsidence of the surfaces that are scarified and compacted should be between 1 and 3 tenths of a foot. This will vary depending upon the type of equipment used, the moisture content of the soil at the time of grading and the actual degree of compaction attained. FOUNDATION: CONVENTIONAL SPREAD FOOTINGS Load bearing walls may be supported on continuous spread footings and interior columns may be supported on isolated pad footings. All footings should be founded upon properly engineered fill and should have a minimum embedment depth of 12 inches measured from the lowest adjacent finished grade. Continuous and isolated footings should have a minimum width of 12 inches and 24 inches respectively. Continuous and isolated footings placed on such materials may be designed using an allowable (net) bearing pressure of 1800 and 2000 pounds per square foot (psf) respectively. Allowable increases of 250 psf for each additional 1 foot in width and 250 psf for each additional 6 inches in depth may be utilized, if desired. The maximum allowable bearing pressure should be 3,000 psf. The maximum bearing pressure applies to combined dead and sustained live loads. The allowable bearing pressure may be increased by one-third when considering transient live loads, including seismic and wind forces. All footings should be reinforced in accordance with the project structural engineer's recommendations. Based on the allowable bearing pressures recommended above, total settlement of the shallow footings are anticipated to be less than one -inch, provided foundation preparations conform to the recommendations described in this report. Differential settlement is anticipated to be approximately half the total settlement for similarly loaded footings spaced up to approximately 40 feet apart. Lateral load resistance for the spread footings will be developed by passive soils pressure against the sides of the footings below grade and by friction acting at the base of the concrete footings bearing on compacted fill. An allowable passive pressure of 300 psf per foot of depth may be used for design purposes. An allowable coefficient of friction 0.45 may be used for dead and sustained live loads to compute the frictional resistance of the footing placed directly on compacted fill. Under seismic and wind loading conditions, the passive pressure and frictional resistance may be increased by one-third. Sladden Engineering October 22, 2010 -10 - Project No. 544-10168 10-10-244 All footing excavations should be observed by a representative of the project geotechnical consultant to verify adequate embedment depths prior to placement of forms, steel reinforcement or concrete. The excavations should be trimmed neat, level and square. All loose, disturbed, sloughed or moisture - softened soils and/or any construction debris should be removed prior to concrete placement. Excavated soil generated from footing and/or utility trenches should not be stockpiled within the building envelope or in areas of exterior concrete flatwork. SLABS -ON -GRADE In order to reduce the risk of cracking and settlement, concrete slabs -on -grade must be placed on properly compacted fill as outlined in the previous sections. The slab subgrades should remain near optimum moisture content and should not be permitted to dry. Prior to concrete pour, all slab subgrades should be firm and unyielding. Disturbed soils should be removed and then replaced and compacted to a minimum of 90 percent relative compaction. Slab thickness and reinforcement should be determined by the structural engineer we recommend a minimum floor slab thickness of 4.0 inches. All slab reinforcement should be supported on concrete chairs to ensure that reinforcement is placed at slab mid -height. Slabs with moisture sensitive surfaces should be underlain with a moisture vapor retarder consisting of a polyvinyl chloride membrane such as 10-mil Visqueen, or equivalent. All laps within the membrane should be sealed and at least 2 inches of clean sand should be placed over the membrane to promote uniform curing of the concrete. To reduce the potential for punctures, the membrane should be placed on a pad surface that has been graded smooth without any sharp protrusions. If a smooth surface can not be achieved by grading, consideration should be given to placing a 1-inch thick leveling course of sand across the pad surface prior to placement of the membrane. SOLUBLE SULFATES Soluble sulfate concentrations were determined to be "moderate" (1,540 ppm) based upon our laboratory testing. Based upon our preliminary testing the use of Type V and/or sulfate resistant mix design may be necessary. However, the soil should to be retested for soluble sulfate concentration after grading and compaction work is completed. Soluble sulfate content of the surface soil should be reevaluated after grading and appropriate concrete mix designs should be established based upon post -grading test results. UTILITY TRENCH BACKFILL All utility trench backfill should be compacted to a minimum relative compaction of 90 percent. Trench backfill materials should be placed in lifts no greater than six inches in their loose state, moisture conditioned (or air-dried) as necessary to achieve near optimum moisture conditions, and then mechanically compacted in place to a minimum relative compaction of 90 percent. A representative of the project soil engineer should test the backfill to verify adequate compaction. Sladden Engineering October 22, 2010 -11 - Project No. 544-10168 10-10-244 EXTERIOR CONCRETE FLATWORK To minimize cracking of concrete flatwork, the subgrade soil below concrete flatwork areas should first be compacted to a minimum relative compaction of 90 percent. A representative of the project geotechnical consultant should observe and verify the density and moisture content of the soil prior to concrete placement. DRAINAGE All final grades should be provided with positive gradients away from foundations to provide rapid removal of surface water runoff to an adequate discharge point. No water should be allowed to be pond on or immediately adjacent to foundation elements. In order to reduce water infiltration into the subgrade soil, surface water should be directed away from building foundations to an adequate discharge point. Subgrade drainage should be evaluated upon completion of the precise grading plans and in the field during grading. Sladden Engineering October 22, 2010 -12 - Project No. 544-10168 10-10-244 LIMITATIONS The findings and recommendations presented in this report are based upon an interpolation of the soil conditions between the exploratory boring locations and extrapolation of these conditions throughout the proposed building area. Should conditions encountered during grading appear different than those indicated in this report, this office should be notified. The use of this report by other parties or for other projects is not authorized. The recommendations of this report are contingent upon monitoring of the grading operation by a representative of Sladden Engineering. All recommendations are considered to be tentative pending our review of the grading operation and additional testing, if indicated. If others are employed to perform any soil testing, this office should be notified prior to such testing in order to coordinate any required site visits by our representative and to assure indemnification of Sladden Engineering. We recommend that a pre -job conference be held on the site prior to the initiation of site grading. The purpose of this meeting will be to assure a complete understanding of the recommendations presented in this report as they apply to the actual grading performed. ADDITIONAL SERVICES Once completed, final project plans and specifications should be reviewed by use prior to construction to confirm that the full intent of the recommendations presented herein have been applied to design and construction. Following review of plans and specifications, observation should be performed by the Soil Engineer during constructionto document that foundation elements are founded on/or penetrate into the recommended soil, and that suitable backfill soil is placed upon competent materials and properly compacted at the recommended moisture content. Tests and observations should be performed during grading by the Soil Engineer or his representative in order to verify that the grading is being performed in accordance with the project specifications. Field density testing shall be performed in accordance with acceptable ASTM test methods. The minimum acceptable degree of compaction should be 90 percent for subgrade soils and 95 percent for Class II aggregate base as obtained by the ASTM D1557-91 test method. Where testing indicates insufficient density, additional compactive effort shall be applied until retesting indicates satisfactory compaction. Sladden Engineering October 22, 2010 - 13 - Project No. 544-10168 10-10-244 REFERENCES Blake, T., 2000, EQFAULT and EQSEARCH, Computer Programs for Deterministic and Probabilistic Prediction of Peak Horizontal Acceleration from Digitized California Faults. Boggs, S. Jr., (2001), "Principles of Sedimentology and Stratigraphy", Prentice Hall, third edition California Building Code (CBC), (2007), California Building Standards Commission. Cao T., Bryant, W.A., Rowshandel B., Branum D., Wills C.J., (2003), "The Revised 2002 California Probabilistic Seismic Hazard Maps". GoogleEarth.com, 2010, Vertical Aerial Photograph for the La Quinta area, California, Undated, Variable Scale. Hart, E. W., and Bryant, W. A., Revised 1997, Fault -Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zones Maps: State of California, Department of Conservation, Division of Mines and Geology Special Publication 42. 38 Pages. Supplements 1 and 2 were added on 1999. Jennings, Charles W. (Compiler), 1994, Fault Activity Map of California and Adjacent Areas, California Division of Mines and Geology, Geologic Data Map No. 6 Riverside County Land Information Systems (RCLIS),available at http://www.tlma.co.riverside.ca.us/gis/gisdevelop.html. Rogers T.H (compiler), Jenkins, O.P (edition) (1965), Geologic Map of California, Santa Ana Sheet, sixth printing 1992, California Division of Mines and Geology, 1: 250,000. TerraSever, Inc., 2002, Aerial Photographs and Topographic Maps at Various Scales. Available at www.terraserve.cont Tyley, S.J., (1974) Analog Model Study of the Ground -Water Basin of the Upper Coachella Valley, California, Geological Survey Water-Suppley Paper 2027. United States Geological Survey (USGS) (1980) Indio 7.5 Minute Quadrangle Map, 1:24000. United States Geological Survey (USGS) (2007), "Detection and Measurement of Land Subsidence Using Global Positioning System and Interferometric Synthetic Aperture Radar, Coachella Valley, California, 1996-2005", Scientific Investigations Report 2007-5251. United States Geological Survey (USGS) (2009), "Seismic Hazard Curves and Uniform Response Spectra, Version 5.0.9a", updated 10/21/2009. Sladden Engineering FIGURES SITE LOCATION MAP REGIONAL GEOLOGIC MAP BOREHOLE LOCATION PLAN Sladden Engineering F � � I _ i �. '• or 33'WaR •'� •,• 40-. — lam.= - 35 apt AVENU ! !'J„g� - ' .. A1%&PAOE -. • J .. .. .. N � .. =_lam - � I '-- -• L s _ ..d .. - . 1. G srrEFli A.7cNrlF / D y i L I I 8 13 1,3 4 _ I`1 -2911 ` �� f{ v • Y \_ Ot r - 15 I � f. Y wvaH r 3. e � Cp�chalsa Yalld>.! - 3 1 I • 'i 14 F � r -\- i. _� S7 2y • _ AVF.! F .- .. ._a'.T. �.J• • We ra.� �- 2v Source: USGS (1980) SITE LOCATION MAP FIGURE Project Number: 544-10168 Report Number: 10-10-244 8ladden Engineering Date: October 22, 2010 CIF � ' osf i` .C� - r � t• gs' - v x, . ,_• U, L- Y Po D �o DC YWater r ..Sring- 1 -- C 3 s 1 '� • qr 1 (�Gl• • 1 f a .� {ry�� G 1 %�, 4 �C• .� a r Palm rip s J <<�--� F s i� - •�� crtnl:� .C` :dR .Cel* hClGS r°c5'a4rt5 'fq Qs i � - _ SITE " L'-` � :`t 7 r � � f _ ;fir � • tiL3J ; 7 ''� ''-+_ ' +. + r-�G3YS�ACKG�JtJf)�1 _ - 7 I lW. e j[�� L AR lJ8 E 7t {�1 'Ln •� •ai L - � l C. � w iiCl i. iS g fair lot 5 • EJ1AlT!Fi _ s�r.rrI.. - at EXPLANATION OF SITE UNITS 1 ,_,� AN 40 y t • " '� C c"a A Elul;um Qtwt<wnary l:Lkc^ elr mi ,. 1�� r'. J , : ti.` cA r w�c '�` 'ter - LVg ,�s �n Vu 0 Mile Cdk1l.ftr."F v �_- y 4 Source: Rogers (1965) _ r ! :�' "�rlks' _ ., .,�.'::, 4 �} A .'{ire/• 1 � REGIONAL GEOLOGIC MAP FIGURE Proiect Number: 544-10168 2 Report Number: 10-10-2,44 Sudden Engineering pate: October 22, 2010 it 4 IN m-A ------------ -- -7:- X Of B P, ca Ivj .06,1 in P 0 W 5 14 UP. B 0 P�F Lai Y AT-T i!A (D CU 2 1 - P 0 W ID d-5 0, 0d p811eA01 6 P Ef BH-3 Approximate Borehole Location and Designation BOREHOLE LOCATION PLAN FIGURE Project Number: 544-10168 3 Report Number: 10-10-244 Sladden Engineering Date: October 22, 2010 APPENDIX A FIELD EXPLORATION Sladden Engineering APPENDIX A FIELD EXPLORATION For our field investigation three (3) exploratory borings were excavated utilizing a truck mounted hollow stem auger rig (Mobile B-61). Continuous logs of the materials encountered were made by a representative of Sladden Engineering. Materials encountered in the boreholes were classified in accordance with the Unified Soil Classification System which is presented in this appendix. Representative undisturbed samples were obtained within our borings by driving a thin -walled steel penetration sampler (California split spoon sampler) or a Standard Penetration Test (SPT) sampler with a 140 pound automatic -trip hammer dropping approximately 30 inches (ASTM D1586). The number of blows required to drive the samplers 18 inches was recorded in 6-inch increments and blowcounts are indicated on the boring logs. The California samplers are 3.0 inches in diameter, carrying brass sample rings having inner diameters of 2.5 inches. The standard penetration samplers are 2.0 inches in diameter with an inner diameter of 1.5 inches. Undisturbed samples were removed from the sampler and placed in moisture sealed containers in order to preserve the natural soil moisture content. Bulk samples were obtained from the excavation spoils and samples were then transported to our laboratory for further observations and testing. Sladden Engineering UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS TYPICAL NAMES CLEAN GRAVELS GW WELL GRADED GRAVEL -SAND MIXTURES w GRAVELS WITH LITTLE OR NO v� FINES GP POORLY GRADED GRAVELS, GRAVEL -SAND o MIXTURES Ci z MORE THAN HALF COARSE FRACTION GM SILTY GRAVELS, POORLY -GRADED GRAVEL - IS SAND SILT MIXTURES LARGER THAN No.4 SIEVE GRAVELS WITH OVER p SIZE 12% FINES GC CLAYEY GRAVELS, POORLY GRADED GRAVEL - SAND -CLAY MIXTURES SW WELL GRADED SANDS, GRAVELLY SANDS _ w SANDS CLEAN SANDS WITH LITTLE OR NO FINES SP POORLY GRADED SANDS, GRAVELLY SANDS xMORE SM SILTY SANDS, POORLY GRADED SAND -SILT THAN HALF COARSE FRACTION w IS MIXTURES SMALLER THAN N0.4 SANDS WITH OVER SIEVE SIZE 12% FINES SC CLAYEY SANDS, POORLY GRADED SAND -CLAY MIXTURES INORGANIC SILTS & VERY FINE SANDS, ROCK ML FLOUR, SILTY OR CLAYEY FINE SANDS, OR CLAYEY SILTS WITH SLIGHT PLASTICITY SILTS AND CLAYS INORGANIC CLAYS OF LOW TO MEDIUM a a LIQUID LIMIT LESS THAN 50 CL PLASTICITY, GRAVELLY CLAYS, SANDY O CLAYS. SILTY CLAYS. CLEAN CLAYS OL ORGANIC CLAYS AND ORGANIC SILTY CLAYS Cn W OF LOW PLASTICITY z�� ¢ w o INORGANIC SILTS, MICACEOUS OR o MH DIATOMACIOUS FINE SANDY OR SILTY SOILS, z z ELASTIC SILTS x SILTS AND CLAYS: LIQUID LIMIT GREATER THAN CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT w 50 CLAYS OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS HIGHLY ORGANIC SOILS Pt PEAT AND OTHER HIGHLY ORGANIC SOILS EXPLANATION OF BORE LOG SYMBOLS _California Split -spoon Sample ®Unrecovered Sample mStandard Penetration Test Sample Note: The stratification lines on the borelogs represent the approximate . Groundwater depth boundaries between the soil types; the transition may be gradual. A-1 BORE LOG SLADDEN ENGINEERING Drill Rig: Mobil B-61 Date Drilled: 9/29/2010 Elevation: 5 Feet (AMSL) Boring No: BH-1 axi � O O Ll. 0 0 o y Description M p x ' Q v U] CO OG W o 0 0 0 U 10/17/22 1 15 41.0 9.8 120.0 2 Silty Sand (SM); light olive brown, moist, medium dense, fine- 4 grained (Fill). 12/23/33 51.0 11.4 123.5 6 Sandy Silt (ML); dark olive brown, moist, hard, low plasticity (Fill). 8 8/11/19 26.8 11.5 10 ; Silty Sand (SM); dark yellowish brown, moist, medium dense, fine- 12 ; ; grained (Fill). 14 3/7/11 34.6 14.9 93.0 16 Silty Sand (SM); light yellowish brown, moist, medium dense, fine- grained with shell fragements (Ql-Qal). 18 3/4/4 51.0 14.5 20 Interbedded Silty Sand and Sandy Silt (SM/ML); light yellowish 22 ``'``` :---`` brown, moist, loose/medium stiff, fine-grained/low plasticity, thinly I:I:I:+:!•; laminated (Ql-Qal). 24 ' 7/8/9 74.0 14.6 92.3 26 Sandy Silt (ML); light yellowish brown, dry, stiff, low plasticity (Ql- Qal). 28 5/7/7 36.4 8.0 30 Silty Sand (SM); olive brown, moist, medium dense, fine-graind (Q1- 32 •' Qal). 34 7/12/12 19.7 5.0 102.4 36 Silty Sand (SM); olive brown, moist, medium dense, fine-graind (Ql- Qal). 38 6/7/11 29.4 8.8 40 Silty Sand (SM); olive brown, moist, medium dense, fine-graind (Ql- 42 Qal). 44 14/19/22 13.3 2.9 108.4 46 Silty Sand (SM); olive brown, moist, medium dense, fine-graind (Ql- Qal). 48 Silty Sand (SM); yellowish brown, moist, medium dense, fine-graind 11J13/13 15.2 3.6 50 (Ql-Qal). Completion Notes: PROPOSED LOTHENBACH RESIDENCE Termianted at --51.5 Feet bgs. LOT 22A WITHIN MADISON CLUB, LA QUINTA, CALIFORNIA Project No: 544-10168 Page 1 No Bedrock Encountered. No Groundwater or Seepage Encountered. Report No: 10-10-244 BORE LOG SLADDEN ENGINEERING Drill Rig: Mobil B-61 Date Drilled: 9/29/2010 Elevation: 5 Feet (AMSL) Boring No: BH-2 x to o 2 S o � a , v ,3 Description d U v v y o x A v v, oo ra w o 0 Q U Silty Sand (SM); light olive brown, moist, fine-grained (Fill). 7 9/21/46 63.4 13.6 122.2 4 - 6 Sandy Silt (ML); olive brown, moist, hard, low plasticity with shell fragments (Fill). - 8 8/12/12 28.7 9.4 10 Silty Sand (SM); dark olive brown, moist, medium dense, fine- 12 grained (Ql-Qal). 14 2/3/3 34.0 11.1 89.3 16 Silty Sand (SM); light yellowish brown, moist, very loose, fine- grained, with shell fragments (Ql-Qal). -18 3/3/3 85.5 30.2 - 20 - Sandy Silt (ML); light yellowish brown, moist, medium stiff, low plasticity (Ql-Qal). 22 24 Termianted at -21.5 Feet bgs. No Bedrock Encountered. 26 No Groundwater or Seepage Encountered. 28 30 32 34 36 38 40 - 42 44 46 48 50 Completion Notes: PROPOSED LOTHENBACH RESIDENCE LOT 22A WITHIN MADISON CLUB, LA QUINTA, CALIFORNIA Project No: 544-10168 Page 2 Report No: 10-10-244 BORE LOG SLADDEN ENGINEERING Drill Rig: Mobil B-61 Date Drilled: 9/29/2010 Elevation: 5 Feet (AMSL) Boring No: BH-3 x to C) C14 U En W Description �2 M x 12 U') .0 0-0 L1 M U Silty Sand (SM); light olive brown, moist, fine-grained (Fill). 2 - 4 7/11/18 65.4 15.4 119.3 6 - Sandy Silt (ML); dark olive brown, moist, very stiff, low plasticty - with shell fragements (Fill). 8 - 6/10/13 21.7 8.8 10- Silty Sand (SM); light yellowish brown, moist, medium dense, fine- 12- grained (QI-Qal). 14- 3/3/7 71.1 32.4 83.0 16- Sandy Silt (ML); olive brown, moist, medium stiff, low plasticity (Ql- Qal). -18- _20— - Silty Sand (SM); light yellowish brown, moist, loose, fine-grained (Ql- 3/4/3 47.6 15.5 Qal). 22-::.;:' 24- Termianted at -21.5 Feet bgs. No Bedrock Encountered. -26- No Groundwater or Seepage Encountered. -28- -30- -32- 34- -36- -38- -40- -42- -44- -46- -48- F50 I Completion Notes: PROPOSED LOTHENBACH RESIDENCE LOT 22A WITHIN MADISON CLUB, LA QUINTA, CALIFORNIA Project No: 544-10168 Page 1 3 F Report No: 10-10-244 APPENDIX B LABORATORY TESTING Sladden Engineering APPENDIX B LABORATORY TESTING Representative bulk and relatively undisturbed soil samples were obtained in the field and returned to our laboratory for additional observations and testing. Laboratory testing was generally performed in two phases. The first phase consisted of testing in order to determine the compaction of the existing natural soil and the general engineering classifications of the soils underlying the site. This testing was performed in order to estimate the engineering characteristics of the soil and to serve as a basis for selecting samples for the second phase of testing. The second phase consisted of soil mechanics testing. This testing including consolidation, shear strength and expansion testing was performed in order to provide a means of developing specific design recommendations based on the mechanical properties of the soil. CLASSIFICATION AND COMPACTION TESTING Unit Weight and Moisture Content Determinations: Each undisturbed sample was weighed and measured in order to determine its unit weight. A small portion of each sample was then subjected to testing in order to determine its moisture content. This was used in order to determine the dry density of the soil in its natural condition. The results of this testing are shown on the Boring Logs. Maximum Density -Optimum Moisture Determinations: Representative soil types were selected for maximum density determinations. This testing was performed in accordance with the ASTM Standard D1557-91, Test Method A. The results of this testing are presented graphically in this appendix. The maximum densities are compared to the field densities of the soil in order to determine the existing relative compaction to the soil. Classification Testing: Soil samples were selected for classification testing. This testing consists of mechanical grain size analyses. This provides information for developing classifications for the soil in accordance with the Unified Soil Classification System which is presented in the preceding appendix. This classification system categorizes the soil into groups having similar engineering characteristics. The results of this testing is very useful in detecting variations in the soil and in selecting samples for further testing. SOIL MECHANIC'S TESTING Expansion Testing: One (1) bulk sample was selected for Expansion testing. Expansion testing was performed in accordance with the UBC Standard 18-2. This testing consists of remolding 4-inch diameter by 1-inch thick test specimens to a moisture content and dry density corresponding to approximately 50 percent saturation. The samples are subjected to a surcharge of 144 pounds per square foot and allowed to reach equilibrium. At that point the specimens are inundated with distilled water. The linear expansion is then measured until complete. Direct Shear Tests: One (1) bulk sample was selected for Direct Shear Tests. This test measures the shear strength of the soil under various normal pressures and is used to develop parameters for foundation design and lateral design. Tests were performed using a recompacted test specimen that was saturated prior to tests. Tests were performed using a strain controlled test apparatus with normal pressures ranging from 800 to 2300 pounds per square foot. Sladden Engineering Consolidation Test: One (1) relatively undisturbed sample was selected for consolidation testing. For this test, a one -inch thick test specimen was subjected to vertical loads varying from 575 psf to 11520 psf applied progressively. The consolidation at each load increment was recorded prior to placement of each subsequent load. The specimens were saturated at 575 psf or 720 psf load increment. Sadden Engineering Sladden Engineering 450 Egan Avenue, Beaumont CA 92223 (951) 845-7743 Fax (951) 845-8863 Maximum Density/Optimum Moisture ASTM D698/D1557 Project Number: 544-10168 Project Name: Lothenbach Residence Lab ID Number: LN6-10380 Sample Location: BH-1 Bulk 1 @ 0-5' Description: Gray Brown Sandy Silt (ML) Maximum Density: 120 pef Optimum Moisture: 12.5% Sieve Size % Retained 3/4" 3/8" #4 145 140 ' 135 • 130 - a 125 • a d A 120 - A s. A 115 110 105 - 100 October 8, 2010 ASTM D-1557 A Rammer Type: Machine _4_ <----- Zero Air Voids Lines, _ sg =2.65, 2.70, 2.75 I, k , 0 5 10 15 Moisture Content, % 20 25 Buena Park • Palm Desert • Hemet Sudden Engineering 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 Job Number: Job Name: Lab ID Number: Sample ID: Soil Description Expansion Index ASTM D 4829 544-10168 Lothenbach Residence LN6-10380 BH-1 Bulk 1 @ 0-5' Gray Brown Sandy Silt (ML) Wt of Soil + Ring: 561.3 Weight of Ring: 191.4 Wt of Wet Soil: 369.9 Percent Moisture: 10.9% Wet Density, pcf: 118.0 Dry Denstiy, pcf: 106.4 Saturation: 1 50.4 Expansion Rack # 1 Date/Time 10/4/2010 1 11:20 AM Initial Reading 0.0000 Final .Reading 0.0153 Expansion Index (Final - Initial) x 1000 15 October 8, 2010 Buena Park • Palm Desert • Hemet Sladden Engineering 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 Direct Shear ASTM D 3080-04 (modified for unconsolidated condition) Job Number: 544-10168 Job Name Lothenbach Residence Lab ID No. LN6-10380 Sample ID BH-1 Bulk 1 @ 0-5' Classification Gray Brown Sandy Silt (ML) Sample Type Remolded @ 90% of Maximum Density October 8, 2010 Initial Dry Density: 107.8 pcf Initial Mosture Content: 12.6 % Peak Friction Angle (0): 30' Cohesion (c): 270 psf Test Results 1 2 3 4 Average Moisture Content, % 20.8 20.8 20.8 20.8 20.8 Saturation, % 99.7 99.7 99.7 ! 99.7 99.7 Normal Stress, kps 0.739 1.479 2.958 5.916 Peak Stress, kps 0.658 1.140 1.952 3.618 6.0 5.0 x 4.0 W L 3.0 2.0 1.0 0.0 L 0 ■ Peak Stress Linear (Peak Stress) 1 2 3 Normal Stress, kps 4 5 6 Buena Park • Palm Desert • Hemet Sladden Engineering 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 Gradation ASTM C117 & C136 Project Number: 544-10168 October 8,2010 Project Name: Lothenbach Residence Lab ID Number: LN6-10380 Sample ID: BH-1 Bulk 1 @ 0-5' Soil Classification: ML Sieve Sieve Percent Size, in Size, mm Passing 2" 50.8 100.0 1 1 /2" 38.1 100.0 1 " 25.4 100.0 3/4" 19.1 100.0 1 /2" 12.7 100.0 3/8" 9.53 100.0 #4 4.75 100.0 #8 2.36 99.9 #16 1.18 99.6 #30 0.60 99.3 #50 0.30 96.7 #100 0.15 83.0 #200 0.075 55.7 100.0 - r - - - ---- 90.0 80.0 70.0 bD 60.0 W 50.0 40.0 30.0..��. 0.0 100.000 10.000 1.000 0.100 0.010 0.001 Sieve Size, mm Buena Park • Palm Desert • Hemet Siadden Engineering 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 Gradation ASTM C117 & C136 Project Number: 544-10168 Project Name: Lothenbach Residence Lab ID Number: LN6-10380 Sample ID: BH-1 R-4 @ 15' October 8, 2010 Soil Classification: SM Sieve Sieve Percent Size, in Size, mm Passing 1 " 25.4 100.0 3/4" 19.1 100.0 1 /2" 12.7 100.0 3/8" 9.53 100.0 #4 4.75 100.0 #8 2.36 100.0 #16 1.18 99.9 #30 0.60 99.8 #50 0.30 98.4 # 100 0.15 74.2 #200 0.074 34.6 too *-► 90 80 70 60 cd 50 P-4 0 _ 40 30 20 - - 0 100.000 10.000 1.000 0.100 0.010 Sieve Size, mm 0.001 Buena Park • Palm Desert • Hemet Sladden Engineering 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 Gradation ASTM C117 & C136 Project Number: 544-10168 Project Name: Lothenbach Residence Lab ID Number: LN6-10380 Sample ID: BH-1 R-10 @ 45' October 8, 2010 Soil Classification: SM Sieve Sieve Percent Size, in Size, mm Passing 111 25.4 100.0 3/4" 19.1 100.0 1 /2" 12.7 100.0 3/8" 9.53 100.0 #4 4.75 100.0 #8 2.36 100.0 #16 1.18 100.0 #30 0.60 99.6 #50 0.30 84.2 #100 0.15 41.7 #200 0.074 13.3 100 - , r 90 80 - - -� — 70 60 50 a 40 30 20 10 04-- 100.000 10.000 1.000 0.100 Sieve Size, mm 0.010 0.001 Buena Park • Palm Desert • Hemet Sladden Engineering 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 Gradation ASTM C117 & C136 Project Number: 544-10168 Project Name: Lothenbach Residence Lab ID Number: LN6-10380 Sample ID: BH-2 S-2 @ 10' October 8, 2010 Soil Classification: SM Sieve Sieve Percent Size, in Size, mm Passing 111 25.4 100.0 3/4" 19.1 100.0 1 /2" 12.7 100.0 3/8" 9.53 100.0 #4 4.75 100.0 #8 2.36 100.0 #16 1.18 99.9 #30 0.60 99.7 #50 0.30 97.7 #100 0.15 78.8 #200 0.074 28.7 100 -s -0 0 �s•�—� 90 0 T 100.000 10.000 1.000 0.100 0.010 0.001 Sieve Size, mm Buena Park • Palm Desert • Hemet Sladden Engineering 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 544-10168 October 8, 2010 Job Name: Lothenbach Residence Lab ID Number: LN6-10380 Initial Dry Density, pcf-. 122.5 Sample ID: BH-1 R-2 @ 5' Initial Moisture, %: 11.4 Soil Description: Gray Brown Sandy Silt (ML) Initial Void Ratio: 0.361 Specific Gravity: 2.67 1 0 -1 -2 y •3 ti bD x -4 -5 U ° -6 -7 -8 -9 -10 % Change in Height vs Normal Presssure Diagram 0 Before Saturation A After Saturation 9 Rebound —N— Hydro Consolidation 0.1 1.0 10.0 100.0 Normal Load (ksf) Buena Park • Palm Desert • Hemet *D Sladden Engineering 6782 Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369 45090 Golf Center Pkwy, Suite F, Indio, CA 92201 (760) 863-0713 Fax (760) 863-0847 450 Egan Avenue, Beaumont, CA 92223 (951) 845-7743 Fax (951) 845-8863 Date: October 8, 2010 Account No.: 544-10168 Customer: Mr. Bob Lothenbach Location: Lot 22A, Madison Club, La Quinta Corrosion Series pH per CA 643 BH-1 @ 0-5' 8.4 Analytical Report Soluble Sulfates per CA 417 ppm 1540 Soluble Chloride per CA 422 ppm 750 Min. Resistivity per CA 643 ohm -cm 420 C Rpt 544-10168 100810