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04-5734 (SFD) Geotechnical Investigation ReportSladden Engineering 6782 Stanton Ave., Suite A,'Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369 ' 39-725 Garand Ln., Suite G, Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895 September 29, 2003 Project No. 544-3407 ' 03-09-624 ' Mr. Andrew Levine Mr: Patrick Mundt 73-318B Shadow Mountain Drive. Palm Desert, California 92260 Project: Proposed Single Family Residence Lot 12 — Polo Estates ' La Quinta, California ' Subject: Geotechnical Investigation ' Presented herewith is the report of our Geotechnical Investigation conducted for the construction of the proposed single family residence to be located at Lot 12 on Vista Montana Road within the La Quinta Polo Estates development in the City 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 single family residence and the related site improvements: This report presents the results of our. field investigation and laboratory testing along with ' conclusions and recommendations for foundation design and site preparation. This report completes our initial scope of services as described in our proposal dated September 5, 2003.1 ' 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 QPpFE;SSIp� �0�,��,.ANpF9s icy Brett L. Anders Jz Principal Engineer w Cr No: C 45389 tc EXP• 9130106 SER/pc GEOTECHNICAL INVESTIGATION PROPOSED SINGLE FAMILY RESIDENCE LOT 12 — POLO ESTATES LA QUINTA, CALIFORNIA tSeptember 29, 2003 TABLE OF CONTENTS INTRODUCTION:: ........... ....... ........: :.::................:..............:.. 1. 1 SCOPEOF WORK.................................:..:...:.......:....:.:...............:.:.....:.............................::..:... 1 PROJECTDESCRIPTION.............::.....:............:.:.................................................................... 1 GEOLOGY, AND SEISMICITY.. ... ...................... ........... 2 1 SUBSURFACECONDITIONS .. .... ............................... .................... ......................... 2 LIQUEFACTION ............ .............................. :................................. :...:...................................... 3 CONCLUSIONS AND RECOMMENDATIONS..::......:::.........::.::.:...............:..:..........:........... 3 ' Foundation Design ......... ***................................................................................................... 4 Settlements............................ :..... .......:.....:........... 4 Lateral Design ....:...... ................... .................... ......................:................................. 5 ' Retaining Walls ......... .......................... 5 ExpansiveSoils .......... ..............................................................:................... 5 Concrete Slabs -on -Grade ..:.... ......... .............i .:.. ....................................... 5 Soluble Sulfates ............::...... 5 ' Tentative Pavement Design.. ..:................... ..::.... .......:. .....::.:.................................. 5 Shrinkage and Subsidence............:...............:........:....:...:......:.:.......................................... 6 General Site Grading.........:,.. ::...:.:,.:....:.... .::... ............. . .:....... :........:.....:......... 6 1. Site Clearing... .............. :.: ................. 6 2. Preparation of Buildingrand Foundation Areas...:.......: .... ...:..... .:....:........:......... 6 3. Placement of Compacted Fill......,:.....................................:..:.:................................. 6 ' 4. Preparation of Slab and Pavement Areas.. ........................... 7 5. Testing and Inspection ..:........ .................... ......... ............................................. 7 GENERAL..........................:...:.:.:.......:..::.:......,.........................:...:.....:.......:....:.......:.:.......... 7 REFERENCES......:......... .......: ...:. .................. :: : 1 8 APPENDIX A - Site Plan and Boring,Logs ' Field Exploration APPENDIX B - Laboratory Testing Laboratory Test Results ' APPENDIX C - 1997 UBC Seismic Design Criteria, 1 September 29, 2003 -1- Project No. 544-3407 ' 03-09-624 INTRODUCTION ' This report presents the results of our Geotechnical Investigation performed in order to provide recommendations for site preparation and the design and construction of the foundations for the proposed single family residence., The project site is located at Lot 12 on Vista Montana Road within ' the La Quinta Polo Estates in the City of La Quinta, California. The preliminary plans indicate that the proposed project will include a single-family residence along with various associated site improvements. Associated improvements will include paved roadways, concrete driveways and patios, underground utilities, and landscape areas. ' SCOPE OF WORK t The purpose of our investigation was to determine certain engineering characteristics of the near surface soils on the site in order to develop recommendations for foundation design and site preparation. Our investigation included field exploration, laboratory testing, literature review, ' engineering analysis and the preparation of this report. Evaluation of hazardous materials or other environmental concerns was not within the scope of services provided. Our investigation was performed in accordance with contemporary geotechnical engineering principles and practice. We make no other warranty, either express or implied. " ' PROJECT DESCRIPTION The site is located at Lot 12 on Vista Montana Road within the La Quinta Polo Estates in the City of La Quinta, California. It is our understanding that the project will consist of a single-family residence along with various associated site improvements." It is our understanding that the proposed residence will be of relatively lightweight wood -frame construction and will be supported by ' conventional shallow spread footings and concrete slabs on grade. The associated improvements will include concrete walkways, patios, driveways, landscape areas and various underground utilities. The majority of the subject site is presently vacant and the ground surface is covered with short grass and weeds. The lot to the south of the site remains vacant and there are existing residences to the west of the site across Vista Montana Road. 'The site appears to have, been leveled in conjunction with the initial development of the La Quinta Polo Estates project. Based upon our previous experience with lightweight residential structures,. we expect that isolated column loads will be less than 20 kips and wall loading'will be less than to ' 2.0 kips per linear foot. Grading is expected to include minor cuts and fills to match the nearby elevations and to construct slightly elevated building pads to accommodate site drainage, This does not include removal and recompaction of the bearing soils within the building area., If the. anticipated foundation loading or t site grading varies substantially from that assumed the recommendations included in this report should be reevaluated. 1 Sladden Engineering September 29, 2003 -2- Project No. 544-3407 03-09-624 GEOLOGY AND SEISMICITY The project site is located within the central Coachella Valley that is part of the broader Salton Trough geomorphic province. The Salton Trough is a northwest trending depression that extends from the Gulf of California to the Banning Pass. Structurally the Salton Trough is dominated by several northwest trending faults, most notable of which is the San Andreas system. A relatively thick sequence of sedimentary rocks 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 and minor marine deposits. The mountains surrounding the Coachella Valley are composed primarily of Precambrian metamorphic and Mesozoic granitic rock. The Coachella Valley is situated in one of the more seismically active areas of California. The San Andreas fault zone is considered capable of generating a maximum credible earthquake of magnitude 8.0 and due to its proximity to the project site the distance of approximately 8.9 kilometers should be considered in design fault for the project. Seismic activity along the nearby faults continues to affect the area and the Coachella Valley is considered one of the more seismically active regions in California. - A computer program and pertinent geologic literature were utilized to compile data related to earthquake fault zones in the region and previous seismic activity that may have affected the site. E.Q. Fault Version 3.00 (Blake) provides a compilation of data related to earthquake faults in the region. The program searches available databases and provides both distances to causitive faults and the corresponding accelerations that may be experienced on the site due to earthquake activity along these faults. The attenuation relationship utilized for this project was based upon Joyner & Boore (1987) attenuation curves. The information generated was utilized in our liquefaction evaluation The site is not located in any Earthquake Fault zones as designated by the State but is mapped in the County's Liquefaction and Ground Shaking Hazard Zone V. Several significant seismic events have occurred within the -Coachella Valley during the past 50 years. The events include Desert Hot Springs - 1948 (6.5 Magnitude), Palm Springs - 1986 (5.9 Magnitude), Desert Hot Springs - 1992 (6.1 Magnitude), Landers - 1992 (7.5 Magnitude) and Big Bear - 1992 (6.6 Magnitude). SUBSURFACE CONDITIONS The soils underlying the site consist primarily of fine grained silty sands with scattered generally thin sandy clayey silt layers. As.is typical for the area, the silty sand and thin sandy silt layers are interbedded and vary in thickness. Silty. sands were the most prominent soils within our exploratory borings but several prominent sandy silt and clayey silt layers were also encountered. The silty sands. encountered near the existing ground surface appeared somewhat loose but the deeper silty sand and sandy silt layers appeared relatively firm. Sampler penetration resistance (as measured by field blowcounts) indicate that density generally increases with depth. The site soils were dry on the surface but moist below a depth of approximately 5 feet. J . Sladden Engineering 1 September 29, 2003 -3- Project No., 544-3407 03-09-624 Laboratory testing indicates that the surface soils within the upper 5 feet consist primarily of silty sands. Expansion testing indicates that the surface silty sands are generally non -expansive and are classified as "very low" expansion category soils in accordance with Table 18 -I -B of the 1997, Uniform Building Code. Groundwater was not encountered within our borings that extended to a depth of approximately 50 feet below the existing ground surface: Groundwater should not be a factor in design or construction. LIQUEFACTION Liquefaction occurs with sudden loss of soil strength due to rapid increases in pore pressures within cohesionless soils as a result, of repeated cyclic loading during seismic events. Several conditions must be present for liquefaction to occur including; the presence of relatively shallow groundwater, generally loose soils conditions, the susceptibility of soils to liquefaction based upon grain -size characteristics and the generation of significant and repeated seismically induced ground accelerations. Liquefaction affects primarily loose, uniform grained cohesionless sands with low relative densities. In the case of this project site, several of the factors required for liquefaction to occur are absent. As previously indicated, groundwater was not encountered within our borings that extended to a depth of approximately 50 feet below the existing ground surface. on the site. Due to the depth to groundwater, the potential for liquefaction affecting the site is considered negligible. CONCLUSIONS AND RECOMMENDATIONS Based upon our field investigation and laboratory testing, it is our opinion that the proposed residential development is feasible from a soil mechanic's standpoint provided that the recommendations included in this report are considered in building foundation design and site preparation. - Due to the somewhat loose condition of the surface soils, remedial grading is recommended for the building areas. We recommend that remedial grading within the proposed building areas include the overexcavation and recompaction of the primary foundation bearing soils. Specific recommendations for site preparation are presented in the Site Grading section of this report. Based upon the depth toygroundwater and the generally firm condition of the deeper sand layers, it is our opinion that the.potential for liquefaction.affecting the site is negligible. The remedial grading recommended for building areas will result in the construction of a uniform compacted soil mat beneath all footings. In our opinion, liquefaction related mitigation measures in addition to the site grading and foundation design recommendations included in this report should not be necessary. The site is located in one of the more seismically active areas -in California. Design professionals should be aware. of the site setting and the potential for earthquake activity during the anticipated life of the structure should be acknowledged. The accelerations that may be experienced on the site. (as previously discussed) should be considered in design. The seismic provisions included in the Uniform Building Code for Seismic Zone 4 should be considered the minimum design criteria. Pertinent 1997 UBC Seismic Design Criteria is summarized in Appendix C. 1 1 1 1 1 1 1 1 1 1. 1 1 1 4 September 29, 2003 -4- Project No. 544-3407 03-09-624 Caving did occur within'our borings and the.potential for caving should be expected 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 near surface silty sands will be classified by CalOSHA as Type C. Soil conditions should be verified in the field by a "Competent person". employed by the Contractor. The near surface soils encountered during our investigation were found to be non -expansive. Laboratory testing indicated an Expansion Index `of 0 for the -surface silty sands and sandy silts which corresponds with the "very low" expansion category in accordance with UBC Table 18 -I -B. The following recommendations present more detailed design criteria which have been developed on the basis of -our field and laboratory investigation. The recommendations are based upon non - expansive soils criteria. Foundation Design. The results of our investigation indicate that either conventional shallow continuous footings or isolated• pad footings, that are supported upon properly compacted soils, may be, expected to provide adequate support for the proposed structure foundations. Building pad grading should beperformed as described in the Site Grading Section of this report to provide for -uniform and firm bearing. conditions for the structure foundations. ; Footingsshould extend at least'12 inches beneath lowest adjacent grade. Isolated square or rectangular footings should be at least two feet square and continuous footings should be at least 12. inches wide: Continuous footings may be designed using,an allowable bearing value of 1500 pounds per square foot (psf) and isolated pad .footings may be designed using an allowable bearing pressure of 1800 psf. Allowable increases of 200 psf for each additional 1 foot of width and 250 psf for each additional 6 inches of depth may be utilizedif desired. The maximum allowable bearing pressure should be 2500 psf. The allowable bearing pressures are applicable to dead and frequently applied live' loads. The allowable bearing 'pressures may be increased by 1/3 to resist wind and seismic loading. Care should be taken to see that bearing or subgrade soils are not allowed to become saturated from the ponding of rainwater or irrigation. Drainage from the building area should be rapid and complete. The recommendations provided in the preceding paragraph are based on the assumption that all footings will be supported' upon properly 'compacted engineered fill soils. All grading should be performed under the testing and inspection of the Soils Engineer or ,his representative. Prior to the placement of concrete, ;we recommend that the footing excavations be inspected in order to`verify that they exterid -into 'compacted soil and are free of loose and disturbed materials. Settlements: Settlements resulting from the anticipated foundation loads should be minimal provided that the recommendations included in this -report are considered in foundation design and construction. The estimated ultimate settlements are calculated to be approximately one inch when using the recommended bearing values. As a practical matter, differential settlements between footings can be assumed as one-half of the total settlement. • Sladden Engineering September 29, 2003 -5- Project No. 544-3407 03-09-624 Lateral Design: Resistance to lateral loads can be provided by a combination of friction acting at'the base of the slabs or foundations and passive earth pressure along the sides of the foundations. A coefficient of.friction of 0.40 between soil and concrete may be used with consideration to dead load forces only. A passive earth pressure of 250 pounds per square foot, per foot of depth, may be used for the sides of footings which are poured against properly compacted native or approved non -expansive import soils. Passive earth pressure ' should be ignored within the upper 1 foot except where confined (such as beneath a floor slab). t Retaining Walls: Retaining walls may be necessary to accomplish the proposed construction. Lateral pressures for use in retaining wall design can be estimated using an equivalent fluid weight of 35 pcf for level free -draining native backfill conditions. For walls that are to be restrained at the top, the equivalent fluid weight should be increased to 55 pcf for level free - draining native backfill conditions. Backdrains should be provided for the full height of the walls. Expansive Soils Due to the prominence of `very low" expansion category soils near the surface, the expansion potential of the foundation bearing soils should not be a controlling factor in foundation or floor slab design. Expansion potential should be reevaluated subsequent to grading. Concrete Slabs -on -Grade: All surfaces to receive concrete slabs -on -grade should be underlain by a minimum compacted non -expansive fill thickness of 24 inches, placed as described in the Site Grading Section of this report. Where slabs are to receive moisture sensitive floor coverings or where dampness of the floor slab is not desired, we recommend the use of an appropriate vapor barrier or an adequate capillary break. Vapor barriers should be protected by sand in order to reduce the possibility of puncture and to aid in obtaining ' uniform concrete curing. Reinforcement of slabs -on -grade in order to resist expansive soil pressures should not be ' necessary. However, reinforcement will have a beneficial effect in containing cracking due to concrete shrinkage. Temperature and shrinkage related cracking should be anticipated in all concrete slabs -on -grade. Slab reinforcement and the .spacing of control joints should be ' determined by the Structural Engineer. Soluble Sulfates: The soluble sulfate concentrations of the surface soils were determined to be less than 107 parts per million, which is considered non -corrosive with respect to concrete. The use of Type V cement and specialized sulfate resistant concrete mix designs should not be necessary for any concrete in contact with the native soils. ' Tentative Pavement Design= All paving should be underlain by a minimum compacted fill thickness of 12 inches (excluding aggregate base). This may be performed as described in the Site Grading Section of this report. R -Value testing was not conducted during our ' investigation but based upon the sandy nature of . the surface soils, an R -Value of approximately 50 appears appropriate for preliminary pavement design. The following preliminary onsite pavement section is based upon a design R -Value of 50. ' Onsite Pavement (Traffic Index = 5.0) Use 3.0 inches of asphalt on 4.0 inches of Class 2 base material Sladden Engineering September 29, 2003 -6- Project No. 544-3407 ' 03-09-624 ' Aggregate base should conform to the requirements for Class 2 Aggregate base in Section 26 of CalTrans Standard Specifications, January 1992: Asphaltic concrete should conform to Section 39 of the : CalTrans Standard Specifications. The recommended sections should be provided with a uniformly compacted subgrade and. precise controlof thickness and elevations during placement. Pavement and slab designs are tentative and should be confirmed at the completion of site grading when the subgrade soils are in-place. This wi11 include sampling and testing of the actual subgrade soils and an analysis based upon the specific traffic information 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 20 to 25. percent. Subsidence of the surfaces that are scarified and compacted should be between 0.1 and 0.3 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. These values for shrinkage and subsidence are exclusive of losses that will occur due to the stripping of the organic material from the site and the removal of oversize material. General Site Grading: All grading should be performed in accordance with the grading ordinance of the City of La Quinta, California. The following recommendations have been developed on the basis of our field and laboratory, testing and are intended to provide a uniform compacted mat of soil beneath the building slabs and foundations. 1. Site Clearing: Proper site clearing will be very important. Any existing vegetation, slabs, foundations, abandoned underground utilities or irrigation lines should be removed from the proposed building areas and the resulting excavations should be properly backfilled. Soils that are disturbed during site clearing should be removed and replaced as controlled compacted fill under the direction of the Soils Engineer. 2. Preparation of Building and Foundation Areas: In order to provide adequate and uniform bearing conditions, we recommend overexcavation throughout the.proposed building areas. The building areas should be overexcavated to a depth of at least 2 feet below existing grade or 2 feet below the bottom of the footings, whichever is ,deeper. The exposed soils should then be scarified to a depth of .1 foot, moisture conditioned and recompacted to' at least 90 percent relative compaction. The excavated material may then be replaced as engineered fillmaterial as recommended below. 3. Placement of Compacted Fill: Within the building pad areas, fill materials should be spread in thin lifts, and .compacted at near optimum moisture content to a minimum of 90 percent relative compaction. Imported fill material shall have -an Expansion Index not exceeding 20. The contractor shall notify the Soils Engineer at least 48 hours in advance of importing soils in order to provide sufficient time" for the evaluation of proposed import materials. The contractor shall be responsible for delivering material to the site which complies with the project specifications. Approval by the Soils Engineer will be based upon material delivered to the site and not the preliminary evaluation of import sources. Sladden Engineering September 29, 2003 -7- Project No. 544-3407 03-09-624 Our observations of the materials encountered during our investigation indicate that compaction within the native soils will be most readily obtained by means of heavy rubber tired equipment and/or.sheepsfoot compactors. A uniform and near optimum moisture content should be maintained during fill placement and compaction. 4. Preparation of Slab and Paving Areas All surfaces- to receive asphalt concrete paving or exterior concrete slabs -on -grade, should be underlain by a minimum compacted fill thickness of 12 inches. This may be accomplished by a combination of overexcavation, scarification and recompaction of the surface, and replacement of the excavated material as controlled compacted fill. Compaction of the slab and pavement areas should be to a minimum of 90 percent relative compaction. 5. Testing and Inspection= During grading tests and observations should be performed 'by the Soils 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 applicable ASTM test standards. The minimum acceptable degree of compaction shall be 90 percent of the maximum dry density 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. GENERAL The findings and recommendations' presented in this report are based upon an interpolation of the soil conditions between 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. This report is considered to be applicable for use by Mr. Andrew Levine and Mr. Patrick Mundt for the specific site and project described herein. 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 operations by a representative of Sladden Engineering. All recommendations are considered to be tentative pending our review of the grading operations 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. r + September 29, 2003 =8- Project No. 544-3407 ' 03-09-624 REFERENCES r ti ASCE Journal of Geotechnical Engineering Division, Apri11974. ' Boore, Joyner and Fumal (1994) Estimation of Response Spectra and Peak Accelerations from North American Earthquakes, U. S. Geological Survey, Open File Reports 94-127 and 93-509. �. Finn, W: E. Liam, (1996) Evaluation ofLiquefaction Potential for Different Earthquake Magnitudes ' and Site Conditions, National Center for Earthquake Engineering Research Committee. Joyner and Boore, (1988) Measurements, Characterization and Prediction of Strong Ground Motion, ' ASCE Journal of Geotechnical Engineering, Special Publication No. 20. t Lee & Albaisa (1974) "Earthquake Induced Settlements in Saturated Sands'_ ' Seed and Idriss (1982) Ground Motions and Soil Liquefaction During Earthquakes, Earthquake Engineering Research Institute Monograph. Seed, Tokimatsu, Harder and Chung, (1985), Influence of SPT Procedures in Soil Liquefaction Resistance Evaluations, ASCE Journal of Geotechnical Engineering, Volume 111, No. 12, December.- Rogers, ecember. Rogers, Thomas H., Geologic Map of California, Santa -Ana Map Sheet. Riverside. County, 1984; Seismic Safety"Element of the Riverside County General Plan ` f r ` •�7• i Sladden Engineering r ', APPENDIX A' FIELD EXPLORATION For our field investigation, 6 exploratory borings were excavated on September 12-2003, using a truck mounted hollow stem auger rig (Mobile B-61) in the approximate locations indicated on the site plan included in this appendix. Continuous log of the materials encountered were made on the site by a representative of Sladden Engineering. Boring logs are included'in this appendix. Representative .undisturbed samples were obtained within our boring by driving a thin-walled steel penetration sampler (California split spoon sampler) or a Standard Penetration Test (SPT) sampler with a 140 pound hammer dropping approximately 30 inches (ASTM D1586). The number of blows required to drive the samplers 18 inches was recorded (generally in 6 inch increments). Blowcounts are indicated on the boring log. 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. T -f 7 A VE 48 48 3-D TopoQuads Copyright ID 1999 DeLorme Yarmouth, ME 04096 Source Data: tiSGS 1000 n Scale: I :15,000 Detail: 13-0 Datum: WGS84 4. Hi Vicinity Map Proposed Single Family Residence Lot 12 - Polo Estates North Vista Montana Road La uinta, California Sladden Engineering Project Number: 544-3404 Date: 9-30-03 - 1 M 1� w!"! %��:.. 29' AVE �Tnaiier f' :. ,.•. x 1•'11 h'll i' o • u Tral! r Park • II •. :�vl yr _ 666 'frai:ar 'PA'k �! " n `r � FIItIW I •.• •.n I• O I 1i'._ :'lit J 'r _ ` �, 1 y': - .„ ;Well. J'II. • `�`��. �J OLF.� - hV � U111r n• 1 , � 3z !b'.•D 33x.We1 4 .50 NM33 (Y 9 rJ _ w.water -•� 1 Js. V� AVENUE+ WAIT <, SITE ..g ..._. e .,,ta..b ate P,I :u tyq�� • .e P � 1 .i\ TI::IP ,•� Va1M� i.n .0 P� r,ix 11 5? -1 i� - AVENu �^ n 4 • L� x Pump _ .i .. � •��-. i • r, n O t/I �' y 9 A X19: _ 7 A V NUE 9C _ __ _—_ _ —i.�___.___=.r ___ A _ _ .;•. T -f 7 A VE 48 48 3-D TopoQuads Copyright ID 1999 DeLorme Yarmouth, ME 04096 Source Data: tiSGS 1000 n Scale: I :15,000 Detail: 13-0 Datum: WGS84 4. Hi Vicinity Map Proposed Single Family Residence Lot 12 - Polo Estates North Vista Montana Road La uinta, California Sladden Engineering Project Number: 544-3404 Date: 9-30-03 - 1 M 1� w!"! %��:.. 29' AVE �Tnaiier f' :. ,.•. x 1•'11 h'll i' o • u Tral! r Park • II •. :�vl yr _ 666 'frai:ar 'PA'k �! " n `r � FIItIW I •.• •.n I• O I 1i'._ :'lit J 'r _ ` �, 1 y': - .„ ;Well. J'II. • `�`��. �J OLF.� - hV � U111r n• 1 , � 3z !b'.•D 33x.We1 4 .50 NM33 (Y 9 4 APPENDIX B LABORATORY TESTING Representative bulk and relatively undisturbed soil samples were obtained in the field and returned 1 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 Log. 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 t determine the existing relative compaction to the soil. This is shown on the Boring Log, and is useful in estimating the strength and compressibility of the soil. Classification Testing: Soil samples were selected for classification testing. This testing consists of ' mechanical grain size analyses and Atterberg Limits determinations. These provide information for developing classifications for the soil in accordance with the Unified Classification System. This classification system categorizes the soil into groups having similar engineering characteristics. The ' results of this testing are very useful in detecting variations, in the soils and in selecting samples for further testing. a SOIL MECHANIC'S TESTING Direct Shear Testing: One bulk sample was selected for Direct Shear Testing. This testing measures the shear strength of the soil under various normal pressures and is used in developing parameters for foundation design and lateral design. Testing was performed using recompacted test specimens, which were saturated prior to. testing. Testing was performed using a strain controlled test apparatus with normal pressures raning from 800 to 2300 pounds per square foot. Expansion Testing= - One 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. t Consolidation Testing: Eight relatively undisturbed samples were selected for consolidation testing. For this testing one -inch thick test specimens are subjected to vertical loads varying'frorn 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 the 575 psf or 720 psf load increment. ' Sep -25-03.01=54P Sladden Engineering 714-523-1369 P_01 F' ANAHEIM TEST LABORATORY ' 3008 S. ORANGE AVENUE SANTA ANA, CALIFORNIA 92707. J PHONE (714) 549-7267 � 1 n TO: SLADDEN ENGINEERING• s -, 6782 STANTON AVE. SUITE A' ' ' BUENA PARK, CA; 90621 c +` DATE.` 9/23/03 P.O. No. Chain of Custody Shipper No. ATTN: BRETT/DAVE- ., Lob. No. A-3826 ' Speciticotion: . ' ' Motetim' SOIL PROJECT: #544 -3407 - 544-3407 BULK'1 @ 0-5,. BULK' 1 ' ANAL•YTICAL REPORT ' CORROSION SERIES SUMMARY OF DATA pH SOLUBLE SULFATES'.SOLUBLE CHLORIDES MIN., RESISTIVITY per CA. 417' per_CA..422 sper CA. 643. ,. ' . ppm fi -ppm, ohm -cm 7.0 ,107 262 1,153 ULLY S M1.Fc?M 74REP w2 v D Chid C ` t f , r :fi September 29, 2003 -14- Project No. 544-3407 j 03-09-624 1997 UNIFORM BUILDING CODE SEISMIC'DESIGN INFORMATION The International Conference of Building Officials 1997 -Uniform Building Code contains substantial revisions and additions to the earthquake engineering section in Chapter 16. Concepts contained in the code that will be relevant to construction of the proposed structures are summarized below. Ground shaking is expected. to be the primary hazard most,.likely to affect the site, based upon proximity to significant faults capable of generating large earthquakes. Major fault zones considered to be most likely to create strong ground shaking at the site are listed below. Based on our field observations and understanding of local geologic conditions, the soil profile type judged applicable to this site is SD, generally described as stiff'or dense soil. The site is located within UBC Seismic Zone 4. The following table presents additional coefficients and factors relevant to seismic mitigation for new construction upon adoption of the 1997,code. 'Approximate Distance Fault Type Fault Zone From Site (1997 UBC) r San Andreas 8.9 km A San Jacinto 31.3 km A Based on our field observations and understanding of local geologic conditions, the soil profile type judged applicable to this site is SD, generally described as stiff'or dense soil. The site is located within UBC Seismic Zone 4. The following table presents additional coefficients and factors relevant to seismic mitigation for new construction upon adoption of the 1997,code. r Sladden Engineering 'Near -Source Near -Source Seismic Seismic Seismic Acceleration . Velocity ` Coefficient Coefficient Source Factor, Na " Factor; N, ..Ca - C" San Andreas 1.05 1.3 0.44Na 0.64N, - San Jacinto 1.0 -1.0 0.44Na 0.64N,. r Sladden Engineering J. E Q F A U L T *, Version 3.00 I DETERMINISTIC.ESTIMATION OF PEAK ACCELERATION. FROM DIGITIZED FAULTS 0B NUMBER: 544-3407 DATE: 09-25-2003 9B NAME: Lot 12 - Polo Estates Vista Montana Road La Quinta, Cal-ifornia 4LCULATION NAME: Test Run Analysis B,ULT-DATA-FILE NAME: CDMGFLTE.DAT ITE COORDINATES: SITE LATITUDE: 33.6826 SITE LONGITUDE: 116.2548 :ARCH RADIUS: 100 mi PTENUATION RELATION: 5) Boore et al. (1997) Horiz. — SOIL (310) UNCERTAINTY (M=Median, S=Sigma).: M Number of Sigmas: 0.0 DISTANCE MEASURE: cd 2drp SCOND: 0 f. Basement Depth: 5.00 km Campbell SSR: Campbell SHR: COMPUTE,PEAK HORIZONTAL ACCELERATION , kULT-DATA FILE USED: CDMGFLTE.DAT [NIMUM DEPTH VALUE (km) c 0.0 _ EQFAULT SUMMARY --------------- r. - • DETERMINISTIC ----------------------------- SITE PARAMETERS' Page 1 1 (ESTIMATED MAX. EARTHQUAKE EVENT I APPROXIMATE I ------------------------------- ABBREVIATED •1 DISTANCE I MAXIMUM 1 PEAK JEST. SITE FAULT NAME I mi. (km) (EARTHQUAKE( SITE (INTENSITY I _______________________________=1=====_______= I MAG.(Mw),I ACCEL. g 1MOD.MERC. SAN ANDREAS - Coachella,. 1 5.5( 8.9)1 7.1 1 0.366 1 IX SAN ANDREAS -'Southern - - 1 '5. 5 ( 8.9) 1'- 7 4 1 0.429 ; 1 X . . BURNT MTN. " 1.•19.4(, 31..3)1 6.4 1 0.107 I VII EUREKA PEAK `''I • 20.2 (' 32. 5) 1 6.4 1 0_104 1 VII SAN JACINTO-ANZA .J '20.6( 33.2)1• 7.2 I 0.156 I VIII SAN ANDREAS -.San' Bernardino` "v1 21.0( 33.8)1 7.3' J 0.162 1 VIII SAN-JACINTO-COYOTE CREEK j ;-1 '21.3(, 34 .•3) 1- �6. 8 i 0.123 I VII PINTO MOUNTAIN 1 32.2( -51.8)1 -7.0 .; I 0.100 1 VII EMERSON So. -COPPER MTN. 1-,33.1( 53.2)1' 6: 9; 1 0:093 1 VII SAN JACINTO - BORREGO 1. 33.6( ,54.0)16.•6 1 0.078 1 VII LANDERS �' 1 '34.5( 55.5) 1 7. 3 1 0.111 I VII ` PISGAH-BULLION MTN.-MESQUITE LK -`1 34.5( '55.6)1 -7.1 1 0.100 I VII SAN JACINTO-SAN JACINTO VALLEY 1. 38.3( 61.6)1 6.9 1 0.083 I VII -BRAWLEY SEISMIC ZONE ,1. 39.1( 63.0)1 6.4 1 0.063 1 VI EARTHQUAKE VALLEY ,1� 39.4( 63.4)1• 6,5. 1 0.066 1 VI NORTH FRONTAL FAULT ZONE (East) '1 39.5( 63.6)1` 6.7 .1 0.089 1 VII ELSINORE-JULIAN `''J 43.2 ( 69.5) 1 7.1. .J 0.084, 1 VII JOHNSON VALLEY (Northern) „11 45.2( 72.8)1 .6.7 1 0.066 1 VI ELMORE RANCH J,• 46.5( 74.8) 1 - 6.6 1 0.061 1 VI 'CALICO - HIDALGO. 1 46.7(: 75.1)1' 7.1 i 0.079+ 1 VII ELSINORE-TEMECULA 1 .48.5( 78.0):J 6.8 1 0.066 I VI ELSINORE-COYOTE MOUNTAIN 1 50.0( 80:4)1 6.8' 1' 0.064 1 VI LENWOOD-LOCKHART-OLD WOMAN SPRGSI 51.3( 82.5)_1 7•.3 .1. 0.082 I VII SUPERSTITION MTN. (San Jacinto) 1` 51'.3(° 82.6)1' 6-.6 1 0.056 1 VI NORTH FRONTAL FAULT ZONE (West)�1 51.7( 83.2)1- 7.0 `•I* 0.084 1 VII SUPERSTITION HILLS =(San Jacinto)] 52.1( 83.9)1. 6.6 •1 x'0.056, 1 VI , HELENDALE - S. LOCKHARDT 1 .59.3( 95.4)1,,- 7.1 1 '0.066 J VI SAN JACINTO-SAN BERNARDINO 1 .,61.0( 98.2)•1 6.7 1 0.052 1 VI ELSINORE-GLEN IVY 31. 62.9( 101.2)1•'.6.8, 1 0.054 1, VI IMPERIAL 1. 66.2( 106.6) 1, '' 7.0 1 0.057 1 VI CLEGHORN !1- 68.5( 110.'3) 1 6.5 j 0.043 1 VI LAGUNA SALADA 1 69.5( 111.9),1 7.0 1,= 0.055 1 VI ,CUCAMONGA 1 76.2(.122.6)1` 7.0 1 0.062 1 VI CHINO -CENTRAL AVE. (Elsinore). 1 76.2( 122.6)1 6.7 1 0.053 J'; VI ROSE CANYON 'I. -76.6( 123.2) 1 6.9 1 0.048. 1 VI NEWPORT-INGLEWOOD (Offshore) `61 •76.7( 123.4).1 6.9 1 0.048 31 VI WHITTIER 1 80.3( 129.3)1 '6. 8- 1 0.044 1 VI SAN ANDREAS - Mojave' 1 c85.2( 137.1)1 -J.1 1 0.050 1 VI SAN ANDREAS - 1857 Rupture.: 1 85.2( 137.1)1 7.8 , 1 0.072 1 VI SAN JOSE 1. •87.7(..141.2),1' "6.5 1 ., 0.043 1 VI DETERMINISTIC'SITE PARAMETERS ----------------------------- Page 2 ----,•--- I _ -------------------------- ----. ---------- (ESTIMATED MAX. EARTHQUAKE EVENT .. I APPROXIMATE -1-'--------------------'--------- ABBREVIATED 1 DISTANCE I MAXIMUM I PEAK JEST. SITE ' FAULT NAME 1 mi (km) (EARTHQUAKE( SITE (INTENSITY I I' MAG. (Mw) I ACCEL. g 'IMOD. MERC. ' GRAVEL HILLS -.HARPER LAKE 1, 90.7( 145.9)1 6'.9,.y 1 0.043 1 VI SIERRA MADRE 1 ` .90.7(, 145.9) I 7'.0 1 0.055 1 VI CORONADO BANK 1 91.5,( 197.3)1 7.4, 1 0.055 1 VI w ELYSIAN PARK THRUST 1 92.7( 149.2)1,• '6.`7 I 0.046` 1 VI ' NEWPORT-INGLEWOOD (L.A.Basin) :5,1 96.1,( 154.7)1 6.9 1 0.041 I V COMPTON .THRUST 1 99-.2( 159.6) 1. _6'.8 1 0.046 1 VI CLAMSHELL-SAWPIT .. 1 99.2( 159.7)1, %6.5 1 0:039 I V . 4 -END OF SEARCH- 97 FAULTSFOUNDWITHIN THE SPECIFIED SEARCH RADIUS. THE SAN ANDREAS - Coachella. ' ,+ v FAULT IS CLOSES'T,TO THE SITE. ' IT IS' ABOUT 5.5 MILES (8. 9 km) --"WAY_ ' I a 16• •.. , z LARGEST MAXIMUM -EARTHQUAKE SITE ACCELERATION: "0.4290 � a 1 1100 ' 1000 ' 900 ' 800 700 t 600 ' 500 ' 400 300 -200 ' 100 0 CALIFORNIA FAULT MAP_ Lot 12 -Polo Estates / Vista Montana Road