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Cantera at Coral Mountain TR 31249 BCPR2023-1000 - Geotechnical ReportUPDATED GEOTECHNICAL AND INFILTRATION EVALUATION FOR TRACT No. 31249 SOUTH OF AVENUE 58 AND WEST OF MADISON STREET LA QUINTA, RIVERSIDE COUNTY, CALIFORNIA PROJECT No. 2589-CR PREPARED FOR BEAZER HOMES 3 10 COMMERCE, SUITE 150 IRVINE, CALIFORNIA 92602 PREPARED BY GEOTEK, INC. 1548 NORTH MAPLE STREET CORONA, CALIFORNIA 92878 GEOTEK'G:� UARY 21.2021 GeoTek, Inc. 1548 North Maple Street. Corona, California 92878 (951) 710-1 160 Office (951) 710-1 167 Fax www.geotekusa.com January 21, 2021 Project No. 2589-CR Beazer Homes 310 Commerce, Suite 150 Irvine, California 92602 Attention: Ms. Suzy Charnley Subject: Updated Geotechnical and Infiltration Evaluation Tract No. 31249 South of Avenue 58 and West of Madison Street La Quinta, Riverside County, California Dear Ms. Charnley: We are pleased to provide the results of our updated geotechnical report for the subject project located in the city of La Quinta, Riverside County, California. This report presents the results of our evaluation and discussion of our findings. Based on the results of our evaluation, development of the property appears feasible from a geotechnical viewpoint provided that the recommendations presented in this report and in future reports are incorporated into design and construction. GEOTECHNICAL I ENVIRONMENTAL I MATERIALS BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 2 The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to call our office. Respectfully submitted, GeoTek, Inc. F-D C'FO o„ Cr WQ Na 1892 =+ NI Exp. _� rn ,� C'rf i f Gd��`�' T� rag OQ OF CA�-�F /aFcdllR, No.2012 C r% `c0T � ECttN Edward H. LaMont Robert R. Russell CEG 1892, Exp. 07/31 /22 GE 2042, Exp. 12/31 /22 Principal Geologist Senior Project Engineer Distribution: (1) Addressee via email G:\Projects\2551 to 2600\2589CR Beazer Homes Tract 31249 The Village at Coral Mountain La Quinta\Geotechnical Evaluation\2589CR Updated Geotechnical Report La Quinta.doc GEOTEK'G, BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation — Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page i TABLE OF CONTENTS I. PURPOSE AND SCOPE OF SERVICES............................................................................................. I 2. SITE DESCRIPTION AND PROPOSED DEVELOPMENT...............................................................2 2.1 SITE DESCRIPTION..................................................................................................................................................................2 2.2 PROPOSED DEVELOPMENT....................................................................................................................................................2 2.3 PRIOR REPORT REVIEW...........................................................................................................................................................3 3. FIELD EXPLORATION AND LABORATORY TESTING................................................................4 3.1 FIELD EXPLORATION..............................................................................................................................................................4 3.2 INFILTRATION TEST INFORMATION.......................................................................................................................................4 3.3 LABORATORY TESTING..........................................................................................................................................................5 4. GEOLOGIC AND SOILS CONDITIONS...........................................................................................6 4.1 REGIONAL SETTING................................................................................................................................................................6 4.2 EARTH MATERIALS..................................................................................................................................................................6 4.2.1 Existing Fill.......................................................................................................................................................................................7 4.2.2 Alluvium............................................................................................................................................................................................7 4.4 FAULTING AND SEISMICITY....................................................................................................................................................7 4.4.1 Seismic Design Parameters..........................................................................................................................................................8 4.5 LIQUEFACTION AND SEISMICALLY INDUCED SETTLEMENT...............................................................................................9 4.6 OTHER SEISMIC HAZARDS...........................................................................................................................................10 S. CONCLUSIONS AND RECOMMENDATIONS.............................................................................. 10 5.1 GENERAL................................................................................................................................................................................10 5.2 EARTHWORK CONSIDERATIONS........................................................................................................................................ 10 5.2.1 General............................................................................................................................................................................................10 5.2.2 Site Clearing and Demolition................................................................................................................................................... 11 5.2.3 Remedial Grading........................................................................................................................................................................ 11 5.2.4 Engineered Fill............................................................................................................................................................................... I I 5.2.5 Excavation Characteristics........................................................................................................................................................ 12 5.2.6 Trench Excavations and Back fill............................................................................................................................................. 12 5.2.7 Shrinkage and Bulking................................................................................................................................................................ 12 5.3 DESIGN RECOMMENDATIONS............................................................................................................................................. 12 5.3.1 Foundation Design Criteria....................................................................................................................................................... 12 5.3.2 Miscellaneous Foundation Recommendations.................................................................................................................... 15 5.3.3 Foundation Setbacks................................................................................................................................................................... 16 5.3.4 Soil Corrosivity............................................................................................................................................................................... 16 5.3.5 Soil Sulfate Content..................................................................................................................................................................... 16 5.3.6 Import Soils.................................................................................................................................................................................... 16 5.4 RETAINING WALL DESIGN AND CONSTRUCTION.......................................................................................................... 17 5.4.1 General Design Criteria.............................................................................................................................................................. 17 5.4.2 Wall Back fill and Drainage....................................................................................................................................................... 17 5.4.3 Restrained Retaining Walls....................................................................................................................................................... 18 5.5 PAVEMENT DESIGN CONSIDERATIONS.............................................................................................................................. 19 5.6 CONCRETE CONSTRUCTION..............................................................................................................................................20 GEOTEK'G, BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page ii TABLE OF CONTENTS 5.6.1 General............................................................................................................................................................................................20 5.6.2 Concrete Flatwork........................................................................................................................................................................20 5.6.3 Concrete Performance................................................................................................................................................................21 5.7 POST CONSTRUCTION CONSIDERATIONS.......................................................................................................................21 5.7.1 Landscape Maintenance and Planting..................................................................................................................................21 5.7.2 Drainage.........................................................................................................................................................................................22 5.8 PLAN REVIEW AND CONSTRUCTION OBSERVATIONS....................................................................................................22 6. LIMITATIONS....................................................................................................................................23 7. SELECTED REFERENCES.................................................................................................................24 ENCLOSURES Figure I — Site Location Map Figure 2 — Exploration Location Map Appendix A — Boring Location Map, Logs of Borings and Laboratory Test Results (Sladden, 2003) Appendix B — Logs of Exploratory Test Pits & CPT Soundings Appendix C — Laboratory Test Results Appendix D — Infiltration Test Data & Porchet Conversion Calculations Appendix E — Liquefaction Analysis Appendix F — General Earthwork Grading Guidelines '91� GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page I 1. PURPOSE AND SCOPE OF SERVICES The purpose of this study was to evaluate the geotechnical conditions for the proposed development. Services provided for this study included the following: ■ Research and review of available geologic and geotechnical data, and general information pertinent to the site, ■ Review of the reports previously prepared for this site by Sladden Engineering, (Sladden, 2003 and 2007), ■ Perform a site reconnaissance, ■ Site exploration consisting of the excavation and sampling of ten exploratory test pits observed and logged by a geologist from our firm, ■ Logging four Cone Penetrometer Test (CPT) soundings extended to depths of about 50 feet, ■ Performance of four infiltration tests in the existing site basin areas, ■ Collection of representative soil samples from the test excavations and performing laboratory testing on select samples, ■ Review and evaluation of site seismicity, and ■ Compilation of this geotechnical report which presents our recommendations for site development. The intent of this report is to aid in the evaluation of the site for future development from a geotechnical perspective. The professional opinions and geotechnical information contained in this report will likely need to be updated based on our review of final site development plans. These should be provided to GeoTek for review when available. '91� GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 2 2. SITE DESCRIPTION AND PROPOSED DEVELOPMENT 2.1 SITE DESCRIPTION The site is rectangular in shape, consists of about 33 acres and located along the south side of 58`" Avenue and is west of Madison Street in the city of La Quinta, Riverside County, California. The site has been graded but the streets are unpaved. Surface vegetation generally consists of low grasses and weeds. Topographically, the site slopes gently downward to the southeast with about 5 feet of elevation differential. The site is bordered to the south, east and west by vacant land and to the north by Avenue 58 with residential development further north. GeoTek reviewed aerial photographs dated 1949, 1953, 1959, 1965, 1973, 1975, 1984, 1996, 2002, 2006, 2009, 2012, 2016 and 2019 that included coverage of the subject site. Based on readily available historic information, most of the site has been vacant land from at least 1949 to 1984. The southeast portion of the site appears to have been used for agricultural purposes from at least 1949 to 1984. In 1984, a mobile home residence and a greenhouse structure is visible in the northwest portion of the site. Additionally, there appears to be an outdoor firearm shooting range on the northeast portion of the site. In the 1996 aerial photograph multiple linear rows of commercial plants are visible in the northwest portion of the Site. The site appears to no longer be utilized for commercial purposes and has become vacant in the 2002 aerial photograph. The site appears graded for residential development in the aerial photograph, dated 2006. No significant changes are visible from 2006 to the present. 2.2 PROPOSED DEVELOPMENT Based on a review of the provided Tract Map No. 31249, site development will include the construction of 85 single-family residential structures, stormwater management areas and associated street and lot improvements. We understand that the residential structures will be I or 2-stories in height and will be supported by conventional shallow foundation systems which will utilize conventional on -grade floor slabs. Maximum column and wall loads of about 40 kips and 3 kips per foot have been assumed for the purpose of this report. Once actual 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 3 loads are known, that information should be provided to GeoTek to determine if modifications to the recommendations presented in this report are warranted. Based on the graded nature of the site, we anticipate that the maximum depth of cut and fill will be less than about 2 feet, nor including any remedial grading. As site development planning progresses and plans become available, the plans should be provided to GeoTek for review and comment. Additional engineering analyses may be necessary in order to provide specific earthwork recommendations and geotechnical design parameters for actual site development. 2.3 PRIOR REPORT REVIEW Sladden Engineering, 2003 A Geotechnical Investigation report was prepared by Sladden Engineering. (Sladden, 2003) for the subject site. The Sladden report included eight (8) test borings extended to depths ranging from about 16-'/2 to 51-/2 feet below grade. As noted by Sladden, the site soils consist of silty sands, slightly silty sands, sandy to clayey silt and silty clay. The sandy soils generally possessed a medium dense relative density and the fine-grained silt and clays possessed a stiff consistency. Groundwater was not encountered within any of the Sladden borings. Laboratory testing by Sladden indicated the site soil tested possessed a very low expansion potential. A liquefaction analysis was not included within the Sladden report. Sladden recommended that the existing soils should be removed and replaced as a properly compacted fill to a depth of at least 3 feet below existing grade or 2 feet below the bottom of the planned footings, whichever is deeper. Following site grading, as recommended, Sladden indicated that the planned structures could be supported by conventional shallow foundations and a conventional slab on -grade floor. Corrosion testing of the site soils does not appear to have been performed by Sladden. Copies of the Sladden Boring Location Map, boring logs and laboratory testing are presented in Appendix A. Sladden Engineering, 2007 Sladden issued a Report of Observation and Testing During Rough Grading, dated January 26, 2007 to document their observations and field and laboratory testing performed during site grading activities. Sladden noted that site grading started on November 22, 2005 and was completed 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation — Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 4 on December 26, 2006. Based on the dates of the compaction testing, it appears that grading was initially stopped in January 2006 and then re -started in October 2006. Sladden performed 241 soil compaction tests on the fill soils placed at the site and all tests indicated that the tested soils possessed a relative compaction of at least 90% of the soil's maximum dry density, per ASTM D-1557. It does not appear that any additional Expansion Index tests were performed by Sladden during rough grading to document the expansive characteristics of the as -graded soils. 3. FIELD EXPLORATION AND LABORATORY TESTING 3.1 FIELD EXPLORATION The field exploration for GeoTek's update evaluation was conducted on December 28, 2020 and consisted of excavating ten (10) geotechnical exploratory test pits. In -place density tests and dynamic cone penetrometer (DCP) tests were performed within the test pits to assess the in -situ conditions of the existing fill and underlying alluvium. The results of the density tests and DCP tests are summarized on the test pit logs. The approximate locations of the GeoTek excavations are shown on the Exploration Location Map (Figure 2). Logs of the GeoTek borings are included in Appendix B. Four Cone Penetrometer Test (CPT) soundings were also extended at the site to depths of about 50 feet below grade on December 31, 2020. The CPT tests were performed using a 30- ton CPT rig and were performed per ASTM D-5778. Logs of the CPT soundings are presented in Appendix B. 3.2 INFILTRATION TEST INFORMATION Four infiltration tests (1-1 through 1-4) were performed at the site. The infiltration tests consisted of excavating a 6-inch diameter hand auger boring to a depth of about two feet at the bottom of a 2-foot deep test trench (i.e. total depth of 4 feet). About 2 inches of gravel was placed in the bottom of the test pit and a slotted pvc pipe was installed in the infiltration holes. Water was then placed in the borings to presoak the holes and percolation testing was performed following the pre-soak period. Following presoaking, the percolation tests were performed which consisted of adding water to each test hole and measuring the water drop over a 10-minute period. The water drop was recorded for six test intervals. Water was added to the test holes after each test interval. The field percolation rates were then converted to an infiltration rate using the Porchet Method. GEOTEK'G, BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 5 The infiltration rates are presented in the follow table for each of the borings after the rates had stabilized. Test No. Infiltration Rate inches per hour 1-1 16.0 1-2 16.0 1-3 16.0 1-4 16.0 Copies of the percolation data sheets and infiltration conversion sheets (Porchet Method) are included in Appendix D. Over the lifetime of the storm water disposal areas, the infiltration rates may be affected by silt build up and biological activities, as well as local variations in near surface soil conditions. We recommend that an appropriate factor of safety be applied. It should be noted that the infiltration rates provided above were performed in relatively undisturbed native soils. Infiltration rates will vary and are mostly dependent on the underlying consistency of the site soils and relative density. Infiltration rates will be impacted by weight of equipment travelling over the soils, placement of engineered fill and other various factors. GeoTek, Inc. assumes no responsibility or liability for the ultimate design or performance of the storm water facility. 3.3 LABORATORY TESTING Laboratory testing was previously performed by Sladden for soil samples collected from the site during their prior field exploration program. The results of the prior laboratory testing are presented in Appendix A. Laboratory testing was also performed by GeoTek on selected soil samples obtained from the exploratory test pits. The purpose of the laboratory testing was to confirm the field classification of the soils encountered and to evaluate the physical properties of the soils for use in engineering design and analysis. The optimum moisture content -maximum dry density relationship was established for typical soil types so that the relative compaction of the subsoils could be determined. Direct shear testing was performed on selected samples to help evaluate the bearing capacity of the soils. Expansion index testing was performed on two selected samples to evaluate the expansion 'Gr_' GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 6 potential of the site soils. Chemical testing comprised of pH, soluble sulfate, chloride and resistivity testing was conducted on two selected samples. The maximum density, direct shear, expansion index and chemical test data are presented in Appendix C. 4. GEOLOGIC AND SOILS CONDITIONS 4.1 REGIONAL SETTING The subject property is situated in the Colorado Desert geomorphic province, which is a low- lying barren desert basin that is partially below sea level. The most dominant feature within this province is the Salton Trough that is a large northwest -trending alluvial filled structural block that extends about 180 miles in length. The Coachella Valley forms the northern portion of the Salton Trough and is underlain by a series of sediments that range from Miocene to Recent in age. The Salton Trough is bordered by the Little San Bernardino Mountains to the northeast, foothills of the San Bernardino Mountains to the northwest, and the San Jacinto and Santa Rosa Mountains to the southwest. The San Andreas Fault system extends through the Coachella Valley in a general northwest - southeast trend. More specific to the subject property, the site is located in an area geologically mapped to be underlain by Quaternary age alluvial deposits (Dibblee & Minch, 2008). No active faults are shown in the immediate site vicinity on the map reviewed for the area. The County of Riverside (Map My County website) has designated the site area as "not in fault zone" and "not in a fault line". The site is, however, designated as possessing a "moderate liquefaction potential". 4.2 EARTH MATERIALS A brief description of the earth materials encountered below the site and within the area of anticipated construction is presented in the following section. Based on our field exploration, the area of anticipated improvements is underlain by fill and alluvium. 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 7 4.2.1 Existing Fill Existing fill soils were encountered within all test pits to depths ranging from about 2-/2 to 4-%2 feet below grade. As encountered in the test pits, the existing fill consisted of loose to medium dense silty sand. According to the results of the laboratory testing performed on two samples of the near surface fill, the near surface soils have a "very low" expansion potential (EI=O) when tested and classified in accordance with ASTM D 4829. The test results are provided in Appendix C. 4.2.2 Alluvium The existing fill soils are underlain by alluvium which extends to the maximum depths explored. As encountered in the test pits and CPT soundings, the alluvium consisted of loose to dense silty sand with some zones of stiff to very stiff silty clay. 4.3 SURFACE WATER AND GROUNDWATER 4.3.1 Surface Water If encountered during earthwork construction, surface water on this site is the result of precipitation or possibly some minor surface run-off from immediately surrounding properties. Overall site area drainage is variable due to the topographic nature of the site. Provisions for surface drainage will need to be accounted for by the project civil engineer. 4.3.2 Groundwater Groundwater was not encountered within any of the Sladden or GeoTek excavations at the site. Based on the lack of groundwater encountered, it appears that groundwater will not be a significant factor during site development. Based on a review of groundwater information on the state Department of Water Resources Water Data Library, we estimate a depth to high water at about 30 feet below grade. 4.4 FAULTING AND SEISMICITY The geologic structure of the entire southern California area is dominated mainly by northwest -trending faults associated with the San Andreas system. The site is in a seismically active region. No active or potentially active fault is known to exist at this site nor is the site situated within a State of California designated "Alquist-Priolo" Earthquake Fault Zone (Bryant and Hart, 2007; CGS, 1986). The nearest zoned fault is the San Andreas Fault zone, located approximately 8-1/2miles to the northeast of the site. '91� GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 8 4.4.1 Seismic Design Parameters The site is located at approximately 33.6260' Latitude and -1 16.26150 Longitude. Site spectral accelerations (Sa and Si), for 0.2 and 1.0 second periods for a Class "D" site, was determined from the SEAOC/OSHPD web interface that utilizes the USGS web services and retrieves the seismic design data and presents that information in a report format. Using the ASCE 7-16 option on the SEAOC/OSHPD website results in the values for SM, and Sp, reported as "null - See Section 1 1.4.8" (of ASCE 7-16). As noted in ASCE 7-16, Section 11.4.8, a site -specific ground motion procedure is recommended for Site Class D when the value S, exceeds 0.2. The value S, for the subject site exceeds 0.2. For a site Class D, an exception to performing a site -specific ground motion analysis is allowed in ASCE 7-16 where S, exceeds 0.2 provided the value of the seismic response coefficient, Cs, is conservatively calculated by Eq 12.8-2 of ASCE 7-16 for values of T<_ I.5Ts and taken as equal to 1.5 times the value computed in accordance with either Eq. 12.8-3 for TL>_T> I.5Ts or Eq. 12.8-4 for T>TL. The results, based on the 2015 NEHRP and the 2019 CBC, are presented in the following table and we have assumed that the exception as allowed in ASCE 7-16 is applicable. If the exception is deemed not appropriate, a site -specific ground motion analysis will be required. SITE SEISMIC PARAMETERS Mapped 0.2 sec Period Spectral Acceleration, S5 1.5 Mapped 1.0 sec Period Spectral Acceleration, Si 0.6 Site Coefficient for Site Class "D", Fa 1.0 Site Coefficient for Site Class "D", Fv 1.7 Maximum Considered Earthquake Spectral Response 1.5g Acceleration for 0.2 Second, SMs Maximum Considered Earthquake Spectral Response 1.02g Acceleration for 1.0 Second, SM i 5% Damped Design Spectral Response Acceleration Log Parameter at 0.2 Second, Sys 5% Damped Design Spectral Response Acceleration 0.68g Parameter at I second, SDI Peak Ground Acceleration Adjusted for Site Class Effects, 0.618g PGAm Seismic Design Category D 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 9 4.5 LIQUEFACTION AND SEISMICALLY INDUCED SETTLEMENT Liquefaction describes a phenomenon in which cyclic stresses, produced by earthquake - induced ground motion, create excess pore pressures in relatively cohesionless and low plastic soils. These soils may thereby acquire a high degree of mobility, which can lead to lateral movement, sliding, consolidation and settlement of loose sediments, sand boils and other damaging deformations. This phenomenon occurs only below the water table, but, after liquefaction has developed, the effects can propagate upward into overlying non -saturated soil as excess pore water dissipates. The factors known to influence liquefaction potential include soil type and grain size, relative density, groundwater level, confining pressures, and both intensity and duration of ground shaking. In general, materials that are susceptible to liquefaction are loose, saturated granular soils having low fines content under low confining pressures and some low plastic silts and clays. Based on the review of groundwater data, a historic high groundwater depth of 30 feet was used in our analysis. The soil profiles identified within CPT- I through CPT-4 soundings were used for our liquefaction assessment. A mean magnitude weighted (Mw) seismic event of 7.14 (based on a 2 percent exceedance in 50 years) and a PGAM value of 0.62g were used in our assessment. We assumed that the grading of the proposed residential pads will not incorporate significant cuts and/or fill and therefore the current confining stress will remain unchanged. GeoTek evaluated the liquefaction potential of the on -site soils using the computer program Cliq Version 2.0. The results of the analyses indicated the presence of some localized layers of sands and silts are potentially susceptible to liquefaction and settlement. The following table summarizes the amount of total settlement (liquefaction settlement plus settlement of dry sands) estimated at each CPT location: ESTIMATED SEISMICALLY INDUCED TOTAL SETTLEMENT CPT Sounding Total Settlement (inches) 1 0.14 2 0.5 3 0.71 4 0.2 As noted above, seismically induced settlement of up to about 3/4 inches total and less than '/2 - inch differential over a 30-foot span is estimated for the property. Based on these estimated 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Quinta, Riverside County, California Page 10 magnitudes of seismic -induced settlement, it is our opinion that special mitigation and/or design is not warranted. The estimated seismic settlements should be considered by the project structural engineer. The results of the liquefaction and seismic settlement analyses are presented within Appendix E. Due to the flat topography of the site, the potential for lateral spreads is considered nil. 4.6 OTHER SEISMIC HAZARDS The potential for secondary seismic hazards such as seiche and tsunami is considered to be remote due to site elevation and distance from an open body of water. Due to the absence of a nearby free -face and the very low liquefaction hazard, the potential for lateral spreading is considered to be nil. S. CONCLUSIONSAND RECOMMENDATIONS 5.1 GENERAL Development of the site appears feasible from a geotechnical viewpoint. Specific recommendations for site development provided in this report will need to be further evaluated when development plans are provided for our review. The following sections present general recommendations. More specific geotechnical recommendations for site development can be provided when more finalized site development plans are available for review. 5.2 EARTHWORK CONSIDERATIONS 5.2.1 General Earthwork and grading should be performed in accordance with the applicable grading ordinances of the City of La Quinta, the 2019 California Building Code (CBC) and recommendations contained in this report. The General Grading Guidelines included in Appendix F outline general procedures and do not anticipate all site -specific situations. In the event of conflict, the recommendations presented in the text of this report should supersede those contained in Appendix F. '91� GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page I I 5.2.2 Site Clearing and Demolition Site preparation should start with removal of existing deleterious materials, any existing pavements and vegetation within the planned development areas of the site. All deleterious materials should be properly disposed of off -site. 5.2.3 Remedial Grading Due to age of the existing fill and the presence of some loose soil zones, we recommend that the upper 18" of the existing fill be reprocessed. The recommended reprocessing should extend beneath and laterally at least 5 feet beyond all buildings and beneath any adjacent patio slabs. The reprocessed material, and the fill immediately beneath, should be moisture conditioned to at least optimum moisture content down to 3 feet below finish grade. Beneath street areas and other areas to receive surface improvements, we recommend that the exposed subgrade be proof rolled with a heavy rubber -tired piece of construction equipment (minimum weight of 10 tons) in the presence of a GeoTek representative. Any soil that ruts or excessively deflects during proof rolling should be removed as recommended by GeoTek. Once the base of any removal is approved by a representative of our firm, the exposed soils should be scarified to a depth of about 12 inches, be moisture treated to slightly above the soil's optimum moisture content (ASTM D 1557) and then be compacted to at least 90 percent of the soil's maximum dry density (ASTM D 1557). Testing by GeoTek is recommended to document that the engineered fill soils have been moisture treated and compacted as recommended. 5.2.4 Engineered Fill On -site materials are generally considered suitable for reuse as engineered fill, provided they are free from vegetation, roots, and other deleterious material. Rock fragments greater than 6 inches in maximum dimension should not be incorporated into engineered fill. Engineered fill materials should be placed in horizontal lifts not exceeding 8 inches in loose thickness, moisture conditioned to over the optimum moisture content and compacted to a minimum relative compaction of 90 percent (ASTM D 1557). 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 12 5.2.5 Excavation Characteristics Excavations in the on -site alluvial materials and fill materials should be readily accomplished with heavy-duty earthmoving or excavating equipment in good operating condition. All excavations should be formed in accordance with current Cal -OSHA requirements. 5.2.6 Trench Excavations and Backfill Temporary trench excavations within the on -site materials should be stable at 1:1 inclinations for short durations during construction and where cuts do not exceed 15 feet in height. We anticipate that temporary cuts to a maximum height of four feet can be excavated vertically. Trench excavations should conform to Cal -OSHA regulations. The contractor should have a competent person, per OSHA requirements, on site during construction to observe conditions and to make the appropriate recommendations. Utility trench backfill should be compacted to at least 90 percent relative compaction (as determined per ASTM D 1557). Under -slab trenches should also be compacted to project specifications. Where applicable, based on jurisdictional requirements, the top 12 inches of backfill below subgrade for road pavements should be compacted to at least 95 percent relative compaction. On -site materials may not be suitable for use as bedding material but should be suitable as backfill provided particles larger than 6 inches are removed. Compaction should be achieved with a mechanical compaction device. Ponding or jetting of trench backfill is not recommended. If backfill soils have dried out, they should be thoroughly moisture conditioned prior to placement in trenches. 5.2.7 Shrinkage and Bulking For planning purposes, a shrinkage factor of about 0 to 5 percent may be considered for recompaction of the existing fill. A subsidence loss of less than about 0.1 foot is also estimated. Site balance areas should be available in order to adjust project grades, depending on actual field conditions at the conclusion of earthwork construction. 5.3 DESIGN RECOMMENDATIONS 5.3.1 Foundation Design Criteria Foundation design criteria for a conventional foundation system, for one of two-story structures, in general conformance with the 2019 CBC, are presented below. The soils are anticipated to have a "very low" expansion potential in accordance with ASTM D 4829. 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 13 Typical design criteria for the site based upon a "very low" expansion potential are tabulated below. These are minimal recommendations and are not intended to supersede the design by the project structural engineer. The conventional foundation elements for the proposed buildings should bear entirely in engineered fill soils. Foundations should be designed in accordance with the 2019 CBC. Expansion index and soluble sulfate evaluation of the soils should be performed during construction to evaluate the as -graded conditions. Final recommendations should be based upon the as -graded soils conditions. A summary of our foundation design recommendations is presented in the following table: GEOTECHNICAL RECOMMENDATIONS FOR FOUNDATION DESIGN Design Parameter "Very Low" Expansion Potential Foundation Depth or Minimum Perimeter Beam Depth (inches below lowest adjacent 12 grade) Minimum Foundation Width (Inches)* 12 Minimum Slab Thickness (actual) 4 — Actual Minimum Slab Reinforcing 6" x 6" — W I A/W 1.4 welded wire fabric placed in middle of slab or No. 3 bars at 24 inch centers Two No. 4 reinforcing bars, Minimum Footing Reinforcement one placed near the top and one near the bottom Effective Plasticity Index** N/A Presaturation of Subgrade Soil Minimum of 100% of the optimum moisture (Percent of Optimum) content to a depth of at least 12 inches prior to placing concrete * Code minimums per Table 1809.7 of the 2019 CBC ** Effective Plasticity Index should be verified at the completion of grading 5.3.1.1 An allowable soil bearing capacity of 2,000 pounds per square foot (psf) may be used for design of continuous and perimeter footings 12 inches deep and 12 inches wide, and pad footings 24 inches square and 12 inches deep. Additionally, an increase of one-third may be applied when considering short-term live loads (e.g. seismic and wind loads). 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 14 5.3.1.2 Based on the estimated site grading, we estimate a total static settlement of less than I inch. A differential static settlement of about '/2 inch over a 40-foot span is also estimated. 5.3.1.3 The passive earth pressure may be computed as an equivalent fluid having a density of 250 psf per foot of depth, to a maximum earth pressure of 2,500 psf for footings founded on engineered fill. An allowable coefficient of friction between soil and concrete of 0.4 may be used with dead load forces. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one- third. 5.3.1.4 A grade beam, a minimum of 12 inches wide and 12 inches deep, should be utilized across large entrances. The base of the grade beam should be at the same elevation as the bottom of the adjoining footings. 5.3.1.5 A moisture and vapor retarding system should be placed below slabs -on -grade where moisture migration through the slab is undesirable. Guidelines for these are provided in the 2019 California Green Building Standards Code (CALGreen) Section 4.505.2, the 2019 CBC Section 1907.1 and ACI 360R-10. The vapor retarder design and construction should also meet the requirements of ASTM E 1643. A portion of the vapor retarder design should be the implementation of a moisture vapor retardant membrane. It should be realized that the effectiveness of the vapor retarding membrane can be adversely impacted as a result of construction related punctures (e.g. stake penetrations, tears, punctures from walking on the vapor retarder placed atop the underlying aggregate layer, etc.). These occurrences should be limited as much as possible during construction. Thicker membranes are generally more resistant to accidental puncture than thinner ones. Products specifically designed for use as moisture/vapor retarders may also be more puncture resistant. Although the CBC specifies a 6 mil vapor retarder membrane, it is GeoTek's opinion that a minimum 10 mil thick membrane with joints properly overlapped and sealed should be considered, unless otherwise specified by the slab design professional. The membrane should consist of Stego wrap or the equivalent. Moisture and vapor retarding systems are intended to provide a certain level of resistance to vapor and moisture transmission through the concrete, but do not eliminate it. The acceptable level of moisture transmission through the slab is to a large extent based on the type of flooring used and environmental conditions. '91� GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 15 Ultimately, the vapor retarding system should be comprised of suitable elements to limited migration of water and reduce transmission of water vapor through the slab to acceptable levels. The selected elements should have suitable properties (i.e. thickness, composition, strength, and permeability) to achieve the desired performance level. Moisture retarders can reduce, but not eliminate, moisture vapor rise from the underlying soils up through the slab. Moisture retarder systems should be designed and constructed in accordance with applicable American Concrete Institute, Portland Cement Association, ASTM, CALGreen and California Building Code requirements and guidelines. GeoTek recommends that a qualified person, such as the flooring contractor, structural engineer, architect, and/or other experts specializing in moisture control within the building be consulted to evaluate the general and specific moisture and vapor transmission paths and associated potential impact on the proposed construction. That person (or persons) should provide recommendations relative to the slab moisture and vapor retarder systems and for migration of potential adverse impact of moisture vapor transmission on various components of the structures, as deemed appropriate. In addition, the recommendations in this report and our services in general are not intended to address mold prevention; since we, along with geotechnical consultants in general, do not practice in the area of mold prevention. If specific recommendations addressing potential mold issues are desired, then a professional mold prevention consultant should be contacted. 5.3.1.6 We recommend that control joints be placed in two directions spaced approximately 24 to 36 times the thickness of the slab in inches. These joints are a widely accepted means to control cracks and should be reviewed by the project structural engineer. 5.3.2 Miscellaneous Foundation Recommendations 5.3.2.1 To minimize moisture penetration beneath the slab -on -grade areas, utility trenches should be backfilled with engineered fill, lean concrete or concrete slurry where they intercept the perimeter footing or thickened slab edge. 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 16 5.3.2.2 Soils from the footing excavations should not be placed in the slab -on -grade areas unless properly compacted and tested. The excavations should be free of loose/sloughed materials and be neatly trimmed at the time of concrete placement. 5.3.3 Foundation Setbacks Where applicable, the following setbacks should apply to all foundations. Any improvements not conforming to these setbacks may be subject to lateral movements and/or differential settlements: ■ The outside bottom edge of all footings should be set back a minimum of H/3 (where H is the slope height) from the face of any descending slope. The setback should be at least 7 feet and need not exceed 40 feet. ■ The bottom of all footings for structures near retaining walls should be deepened so as to extend below a 1:1 projection upward from the bottom inside edge of the wall stem. This applies to the existing retaining walls along the perimeter, if they are to remain. ■ The bottom of any proposed foundations for structures should be deepened so as to extend below a 1:1 projection upward from the bottom of the nearest excavation. 5.3.4 Soil Corrosivity Based on the chemical test results presented in Appendix C, the corrosivity test results indicate that the on -site soils are "highly corrosive" to buried ferrous metal. This corrosion classification is obtained from "Handbook of Corrosion Engineering," by Pierre R. Roberge, 2nd Edition, 2000. Recommendations for protection of buried ferrous metal should be provided by a corrosion engineer. Additional corrosion testing should be performed at the time of final site grading to assess the corrosion of potential of the as -graded soils. 5.3.5 Soil Sulfate Content The sulfate content was determined in the laboratory for two representative onsite soil samples. The results indicate that the water-soluble sulfate is less than 0.1 percent by weight which is considered "not applicable" (i.e. negligible) as per Table 4.2.1 of ACI 318. Based upon the test results, no special concrete mix design is required by Code for sulfate attack resistance 5.3.6 Import Soils Import soils should have expansion characteristics similar to the on -site soils. GeoTek also recommends that the proposed import soils be tested for expansion and sulfate potential. GeoTek should be notified a minimum of 72 hours prior to importing so that appropriate sampling and laboratory testing can be performed. 'Gir-, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 17 5.4 RETAINING WALL DESIGN AND CONSTRUCTION 5.4.1 General Design Criteria Recommendations presented herein may apply to typical masonry or concrete vertical retaining walls to a maximum height of six feet. Additional review and recommendations should be requested for higher walls. Retaining wall foundations embedded a minimum of 12 inches into engineered fill should be designed using an allowable bearing capacity of 2,000 psf. An increase of one-third may be applied when considering short-term live loads (e.g. seismic and wind loads). The passive earth pressure may be computed as an equivalent fluid having a density of 250 psf per foot of depth, to a maximum earth pressure of 2,500 psf. A coefficient of friction between soil and concrete of 0.4 may be used with dead load forces. When combining passive pressure and frictional resistance, the passive pressure component should be reduced by one-third. An equivalent fluid pressure approach may be used to compute the horizontal active pressure against the wall. The appropriate fluid unit weights are given in the table below for specific slope gradients of retained materials. Surface Slope of Retained Materials Equivalent Fluid Pressure (PCF) (H:V) Select Backfill* Level 35 2:1 60 *Select backfill should consist of approved materials with an expansion index less than or equal to 20. 5.4.2 Wall Backfill and Drainage Wall backfill should consist of very low expansive soil and should include a minimum one -foot wide section of 3/4- to I -inch clean crushed rock (or approved equivalent). The rock should be placed immediately adjacent to the back of the wall and extend up from the backdrain to within approximately 12 inches of finish grade. The upper 12 inches should consist of compacted on - site materials. The backfill materials should be placed in lifts no greater than eight inches in thickness and compacted to a minimum of 90 percent relative compaction in accordance with ASTM Test 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation — Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 18 Method D 1557. Proper surface drainage needs to be provided and maintained. Water should not be allowed to pond behind retaining walls. Waterproofing of site walls should be performed where moisture migration through the walls is undesirable. Retaining walls should be provided with an adequate pipe and gravel back drain system to reduce the potential for hydrostatic pressures to develop. A 4-inch diameter perforated collector pipe (Schedule 40 PVC, or approved equivalent) in a minimum of one cubic foot per linear foot of 3/4-inch or one -inch clean crushed rock or equivalent, wrapped in filter fabric should be placed near the bottom of the backfill and be directed (via a solid outlet pipe) to an appropriate disposal area. Walls from two to four feet in height may be drained using localized gravel packs behind weep holes at 8 feet maximum spacing (e.g. approximately 1.5 cubic feet of gravel in a woven plastic bag). Weep holes should be provided or the head joints omitted in the first course of block extended above the ground surface. However, nuisance water may still collect in front of the wall. Drain outlets should be maintained over the life of the project and should not be obstructed or plugged by adjacent improvements. 5.4.3 Restrained Retaining Walls Any retaining wall that will be restrained prior to placing backfill or walls that have male or reentrant corners should be designed for at -rest soil conditions using an equivalent fluid pressure of 55 pcf (select backfill), plus any applicable surcharge loading. For areas having male or reentrant corners, the restrained wall design should extend a minimum distance equal to twice the height of the wall laterally from the corner, or as otherwise determined by the structural engineer. 5.4.3.1 Other Design Considerations ■ Retaining and garden wall foundation elements should be designed in accordance with building code setback requirements. A minimum horizontal setback distance of five feet as measured from the bottom outside edge of the footing to a sloped face is recommended. ■ Wall design should consider the additional surcharge loads from superjacent slopes and/or footings, where appropriate. ■ No backfill should be placed against concrete until minimum design strengths are evident by compression tests of cylinders. GEOTEK'G, BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 19 ■ The retaining wall footing excavations, backcuts and backfill materials should be approved by the project geotechnical engineer or their authorized representative. ■ Positive separations should be provided in garden walls at horizontal distances not exceeding 20 feet. 5.5 PAVEMENT DESIGN CONSIDERATIONS Pavement design for proposed on -site roadway improvements was conducted per Caltrans Highway Design Manual guidelines for flexible pavements. Based on the soils encountered within the test borings, we estimate an as -graded R-value of 40 for the roadway subgrade soils. For preliminary pavement design, we have also assumed Traffic Indexes (TI) of 5.0 and 6.0. We recommend that final pavement design be based on R-value testing of the graded street subgrades and the assigned TI values. Based on the assumptions noted, we offer the following preliminary pavement design recommendations. Thickness of Asphalt Thickness of TI Concrete (inches) Aggregate Base (inches) 5.0 3 4 6.0 3 7 The TIs used in our pavement design are considered reasonable values for the proposed street areas and should provide a pavement life of approximately 20 years with a normal amount of flexible pavement maintenance. Irrigation adjacent to pavements, without a deep curb or other cutoff to separate landscaping from the paving may result in premature pavement failure. Traffic parameters used for design were selected based upon engineering judgment and not upon information furnished to us such as an equivalent wheel load analysis or a traffic study. The recommended pavement sections provided are intended as a minimum guideline and final selection of pavement cross section parameters should be made by the project civil engineer, based upon the local laws and ordinates, expected subgrade and pavement response, and desired level of conservatism. If thinner or highly variable pavement sections are constructed, increased maintenance and repair could be expected. Final pavement design should be checked by testing of soils exposed at subgrade (the upper 12 inches) after final grading has been completed. Asphalt concrete and aggregate base should conform to current Caltrans Standard Specifications Section 39 and 26-1.02, respectively. As an alternative, asphalt concrete can 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 20 conform to Section 203-6 of the current Standard Specifications for Public Work (Green Book). Crushed aggregate base or crushed miscellaneous base can conform to Section 200-2.2 and 200-2.4 of the Green Book, respectively. Pavement base should be compacted to at least 95 percent of the ASTM D 1557 laboratory maximum dry density (modified proctor). All pavement installation, including preparation and compaction of subgrade, compaction of base material, placement and rolling of asphaltic concrete, should be done in accordance with the City of La Quinta specifications, and under the observation and testing of GeoTek and a City Inspector where required. Jurisdictional minimum compaction requirements in excess of the aforementioned minimums may govern. Deleterious material, excessive wet or dry pockets, oversized rock fragments, and other unsuitable yielding materials encountered during grading should be removed. Once existing compacted fill are brought to the proposed pavement subgrade elevations, the subgrade should be proof -rolled in order to check for a uniform and unyielding surface. The upper 12 inches of pavement subgrade soils should be scarified, moisture conditioned at or near optimum moisture content, and recompacted to at least 95 percent of the laboratory maximum dry density (ASTM D 1557). If loose or yielding materials are encountered during construction, additional evaluation of these areas should be carried out by GeoTek. All pavement section changes should be properly transitioned. 5.6 CONCRETE CONSTRUCTION 5.6.1 General Concrete construction should follow the 2019 CBC and ACI guidelines regarding design, mix placement and curing of the concrete. If desired, we could provide quality control testing of the concrete during construction. 5.6.2 Concrete Flatwork Exterior concrete slabs, sidewalks and driveways should be designed using a four -inch minimum thickness. No specific reinforcement is required from a geotechnical perspective. However, some shrinkage and cracking of the concrete should be anticipated as a result of typical mix designs and curing practices commonly utilized in industrial construction. Sidewalks and driveways may be under the jurisdiction of the governing agency. If so, jurisdictional design and construction criteria would apply, if more restrictive than the recommendations presented in this report. 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 21 Subgrade soils should be pre -moistened prior to placing concrete. The subgrade soils below exterior slabs, sidewalks, driveways, etc. should be pre -saturated to a minimum of 100% of the optimum moisture content to a depth of 12 inches for "very low" expansive soils. All concrete installation, including preparation and compaction of subgrade, should be done in accordance with the City of La Quinta specifications, and under the observation and testing of GeoTek and a City inspector, if necessary. 5.6.3 Concrete Performance Concrete cracks should be expected. These cracks can vary from sizes that are essentially unnoticeable to more than 1/8 inch in width. Most cracks in concrete while unsightly do not significantly impact long-term performance. While it is possible to take measures (proper concrete mix, placement, curing, control joints, etc.) to reduce the extent and size of cracks that occur, some cracking will occur despite the best efforts to minimize it. Concrete undergoes chemical processes that are dependent on a wide range of variables, which are difficult, at best, to control. Concrete, while seemingly a stable material, is subject to internal expansion and contraction due to external changes over time. One of the simplest means to control cracking is to provide weakened control joints for cracking to occur along. These do not prevent cracks from developing; they simply provide a relief point for the stresses that develop. These joints are a widely accepted means to control cracks but are not always effective. Control joints are more effective the more closely spaced they are. GeoTek suggests that control joints be placed in two directions and located a distance apart approximately equal to 24 to 36 times the slab thickness. Exterior concrete flatwork (patios, walkways, driveways, etc.) is often some of the most visible aspects of site development. They are typically given the least level of quality control, being considered "non-structural" components. We suggest that the same standards of care be applied to these features as to the structures themselves. 5.7 POST CONSTRUCTION CONSIDERATIONS 5.7.1 Landscape Maintenance and Planting Water has been shown to weaken the inherent strength of soil, and slope stability is significantly reduced by overly wet conditions. Positive surface drainage away from graded slopes should be maintained and only the amount of irrigation necessary to sustain plant life should be provided for planted slopes. Controlling surface drainage and runoff and maintaining 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 22 a suitable vegetation cover can minimize erosion. Plants selected for landscaping should be lightweight, deep-rooted types that require little water and are capable of surviving the prevailing climate. Overwatering should be avoided. Care should be taken when adding soil amendments to avoid excessive watering. Leaching as a method of soil preparation prior to planting is not recommended. An abatement program to control ground -burrowing rodents should be implemented and maintained. This is critical as burrowing rodents can decreased the long-term performance of slopes. It is common for planting to be placed adjacent to structures in planter or lawn areas. This will result in the introduction of water into the ground adjacent to the foundations. This type of landscaping should be avoided. Planters within 30 feet of the buildings should be above ground and underlain by a concrete slab. Waterproofing of the foundation and/or subdrains may be warranted and advisable. We could discuss these issues, if desired, when plans are made available. 5.7.2 Drainage The need to maintain proper surface drainage and subsurface systems cannot be overly emphasized. Positive site drainage should be maintained at all times. Drainage should not flow uncontrolled down any descending slope. Water should be directed away from foundations and not allowed to pond or seep into the ground adjacent to the footings and floor -slabs. Pad drainage should be directed toward approved areas and not be blocked by other improvements. Roof gutters should be installed that will direct the collected water at least 20 feet from the buildings. It is the owner's responsibility to maintain and clean drainage devices on or contiguous to their lot. In order to be effective, maintenance should be conducted on a regular and routine schedule and necessary corrections made prior to each rainy season. 5.8 PLAN REVIEW AND CONSTRUCTION OBSERVATIONS We recommend that site grading, specifications, retaining wall/shoring plans and foundation plans be reviewed by this office prior to construction to check for conformance with the recommendations of this report. Additional recommendations may be necessary based on these reviews. We also recommend that GeoTek representatives be present during site '91� GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 23 grading and foundation construction to check for proper implementation of the geotechnical recommendations. The owner/developer should have GeoTek's representative perform at least the following duties: ■ Observe site clearing and grubbing operations for proper removal of unsuitable materials. ■ Observe and test bottom of removals prior to fill placement. ■ Evaluate the suitability of on -site and import materials for fill placement and collect soil samples for laboratory testing when necessary. ■ Observe the fill for uniformity during placement including utility trenches. ■ Test the fill for field density and relative compaction. ■ Test the near -surface soils to verify proper moisture content. ■ Observe and probe foundation excavations to confirm suitability of bearing materials. If requested, a construction observation and compaction report can be provided by GeoTek, which can comply with the requirements of the governmental agencies having jurisdiction over the project. We recommend that these agencies be notified prior to commencement of construction so that necessary grading permits can be obtained. 6. LIMITATIONS This evaluation does not and should in no way be construed to encompass any areas beyond the specific area of proposed construction as indicated to us by the client. Further, no evaluation of any existing site improvements is included. The scope is based on our understanding of the project and the client's needs and geotechnical engineering standards normally used on similar projects in this region. The materials observed on the project site appear to be representative of the area; however, soil and bedrock materials vary in character between excavations and natural outcrops or conditions exposed during site construction. Site conditions may vary due to seasonal changes or other factors. GeoTek, Inc. assumes no responsibility or liability for work, testing or recommendations performed or provided by others. Since our recommendations are based on the site conditions observed and encountered, and laboratory testing, our conclusions and recommendations are professional opinions that are limited to the extent of the available data. Observations during construction are important to allow for any change in recommendations found to be warranted. These opinions have been 'Gir-, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page 24 derived in accordance with current standards of practice and no warranty is expressed or implied. Standards of practice are subject to change with time. 7. SELECTED REFERENCES American Society of Civil Engineers (ASCE), 2017, "Minimum Design Loads for Buildings and Other Structures," ASCE/SEI 7-16. Bowles, J. E., 1977, "Foundation Analysis and Design", Second Edition. Bryant, W.A., and Hart, E.W., 2007, "Fault Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning Act with Index to Earthquake Fault Zones Maps," California Geological Survey: Special Publication 42. California Code of Regulations, Title 24, 2019 "California Building Code," 2 volumes. California Geological Survey (CGS, formerly referred to as the California Division of Mines and Geology), 1977, "Geologic Map of California." , 1998, "Maps of Known Active Fault Near -Source Zones in California and Adjacent Portions of Nevada," International Conference of Building Officials. , 2008, "Guidelines for Evaluating and Mitigating Seismic Hazards in California," Special Publication 117A. , 2010, "Geologic Map of Calif8rnia". Dibblee, T.W. and Minch, J.A., 2003, "Geologic Map of the Palm Desert and Coachella 15 minute Quadrangles", Dibblee Geologic Foundation Map DF-373. GeoTek, Inc., In-house proprietary information. Roberge, P. R., 2000, "Handbook of Corrosion Engineering". SEA/OSHPD web service, "Seismic Design Maps" (https://seismicmaps.org). Sladden Engineering, 2003, "Geotechnical Investigation, Tentative Tract 31249, Avenue 58 West of Madison Street, La Quinta, California", August 20. 2007, "Report of Observation and Testing During Rough Grading, Tract31249-Village at Coral Mountain, Avenue 58 West of Madison Street, La Quinta, California", January 26. Terzaghi, K. and Peck, R. B., 1967, "Soil Mechanics in Engineering Practice", Second Edition. 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Z INorth +- Approximate Boring Locations 1, Boring Location Map Proposed 33-acre Residential Development Tentative Tract 31249 Avenue 58 west of Madison Street La Quinta, California Sladden Engineering Project Number: 544-3272 J Date: 8-20-03 [-Tentative Proposed 33 Acre Residential Development Tract 31249 / Avenue 58 west of Madison Street / La Quinta, California Date: 6-20-03 Boring No. l -, Job No.: 544- ^� � asDESCRIPTION .o FIE REMARKS CU C C o - - - Sand: Brown, SP/SM - slightly silty, fine grained 5 - _ - 8/8/12 �� 106 1 --- 9% passing #200 10 _ 6110114 �� 98 2 --- 9% passing #200 15 " _ 8/10/10 2 --- 9% passing 4200 - 10/10/12 — 2 --- 13% passing #200 25 6/8/12 Silty Clay: Brown, CL _-- 17T--i rl, passing #200 _ slightly sandy as 10/10/12 Sand: Brown, SP/SM -- 2 assing #200 slightly silty, tine grained 35 6/6/12 Sandy Silt: Brown, ML --- 8 -- 151 % passing #200 very sandy 40 _ 6/8/10 Silty Clay. Brown with CL __- 30 -- 93% passing #200 - thin interbedded sand layers I 45 � . 8/8/12 Silty Sand. Brown, SM --- 5 — 17% passing #200 _ I Fine grained so _ 6/8/12 Silty Clay: Brown h` Y CL --- 32 --- ° 95/° passing #200 _ - Recovered Sample Total Depth = 51.5- No Bedrock ss � Standard Penetration Note: The stratification lines represent the approximate No Groundwater boundaries Sample P between the soil types; the transitions may be gradual. Proposed 33 Acre Residential Development Tentative Tract 31249 / Avenue 58 west of Madison Street / La Quinita, California Date: 6-20-03 Borin No 5 6 J0 N CAA 3117'' 0. •p w � i � d p DESCRIPTION ate. y a REMARKS a a A ri U Aa c° � u o o U 0 _ Silty Sand: Brown, SM _ very silty, fine grained 5 _ SiIO/22 Silty Sit Sand: Brown, SM 99 2 ___ 38% passing #200 _ fine grained 10 - - 10/16/24 Sand: Brown, slightly silty fine grained with thin SP/SM 92 2 - 32% passing #200 - interbedded silt layers h5 - 10/18/24 Sand: Brown, slightly silty, SP/SM 112 1 --- 10% passing #200 _ fine grained, trace gravel _ Silty Sand: Brown, SM 20 fine grained with thin _ g 10/16 interbedded silt lavers ] 01 — ° 23 /° passing #200 - -Recovered Sample Total Depth = 21.5' No Bedroc[: No Groundwater 25 30 35 40 45 50 - Note: The stratification lines 55 represent the approximate boundaries between the soil types; the transitions may be gradual. Proposed 33 Acre Residential Development Tentative Tract 31249 / Avenue 58 west of Madison Street / La Quinta, California Date: 6-20-03 — Borine No. 7 Job No. - 544-3272 4j DESCRIPTION d a REMARKS d a o Sandy Silt: Brown, ML ` slightly clayey 5 �Silty 9/18/74 Sand: Brown, SM 99 0 - fine grained ... 23% passing #200 10 _ ' 10/16/22 Sand: Brown, SP/SM 98 1 — 14% passing #200 _ slightly silty, tine grained 15 - 12/16/26 102 2 --- 17% passing #200 20 10/18/24 I06 1 --- 14% passing #200 - - Recovered Sample Total Depth = 21.5' No Bedrock: - No Groundwater zs 30 35 40 45 so - Note: The stratification lines 55 represent the approximate boundaries between the soil types; the transitions may be gradual. Maximum Density/Optimum Moisture ASTM D698/D1557 Project Number: 544-3272 Proj ect Name: Tract 31249 Lab ID Number: Sample Location: Bulk 3 a 0-5' (Max Only) Description: Sandy Silt Maximum Density: 117.5 pcf Optimum Moisture 12.5% Sieve Size % Retained 3/4" 3/8" #4 14, 141 13' 131 110 105 100 0 <-- Zero Air Voids Lines, sg =2.65, 2,70, 2,75 5 10 15 Moisture Content, % July 9, 2003 ASTM D-1557 A Rammer Type: Machine 20 25 Max Density Sladden Engineering Revised 12/03/02 Job Number: 544-3272 Job Name: Tract 31249 Sample ID: Boring I @ 5' Soil Description: Silty Sand One Dimensional Consolidation ASTM D2435 & D5333 July 9, 2003 Initial Dry Density, pcf: 109.2 Initial Moisture, %: 1 Initial Void Ratio: 0.526 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram - 0 Before Saturation After Saturation --6 Rebound — 1-- Hydra Consolidation —m-�-----��,il rrari.--Gn —CCG��''—ir��CCG©G—iA�iGC MMM CGEG ®G' CAE �=E�E000GGG oG' ----------—��ti----I -"---- C CG--- CCCC--CI ��-1- - --C-- ��----1 E_ MMENEEZZIMMmi '�CCCCCCCCCEEmmMIMm,..�Ej==I G�CCGGCCC-MCCCCCCC©C®11 _M-"CEG GGCCCCCGCC GC. mmCC E�CGC�CGCCCC�'MMI =-C=-' CCGG ,•-CC©CEECs C ..MEN "C�CCC-CCCCMMCaMMCCC: > MEZZ m..---aG---------• ZZ 00.1.0 2 1 3.0 6.0 7.0 Consolidation Sladden Engineering Revised 11/20/02 Job Number: 544-3272 Job Name: Tract 31249 Sample ID: Boring 3 cr 5' Soil Description: Sandy Silt _a -4 -5 -6 -7 -S -9 -10 0.0 One Dimensional Consolidation ASTM D2435 & D5333 July 9, 2003 Initial Dry Density, pcf: 95.9 Initial Moisture, %: 7 Initial Void Ratio: 0.943 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram 0 Before Saturation —A After Saturation —9 Rebound —IF Hydro Consolidation 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Consolidation Sladden Engineering Revised 11/20/02 One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 544-3272 July 9, 2003 Job Name: Tract 31249 Initial Dry Density, pcf 89.2 Sample ID: Boring 5 @ 10' Initial Moisture, %: 2 Soil Description: Silty Sand Initial Void Ratio: 0.870 Specific Gravity: 2.67 C -1 -2 -3 -4 -5 -6 -7 -8 -9 -1 Q 0.0 Hydrocollapse: 1.0% @ 0.575 ksf % Change in Height vs Normal Presssure Diagram —0 Before Saturation —A— After Saturation 6—Rebound —;—Hydro Consolidation 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Consolidation Sladden Engineering Revised i l/20/0? Job Number: 544-3272 Job Name: Tract 31249 Sample ID: Boring 7 @ 10' Soil Description: Silty Sand 4 -3 -4 -5 -6 -7 -8 -9 -10 0.0 One Dimensional Consolidation ASTM D2435 & D5333 July 9, 2003 Initial Dry Density, pcf: 93.4 Initial Moisture, %: 1 Initial Void Ratio: 0.785 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram 0 Before Satur, --A After Saturation —e—Rebound --E Hydro Consolidation 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Consolidation Sladden Engineering Revised I U20l02 Direct Shear ASTM D 3080-90 (modified for unconsolidated, undrained conditions) Job Number 544-3272 Job Name Tract 31249 Lab ID No. Sample ID Bulk 1 @ 0-5' Classification Silty Sand Sample Type Remolded @ 90% of Maximum Density July 9, 2003 Initial Dry Density: 104.3 pcf Initial Mosture Content: 15.5 % Peak Friction Angle (0): 31 ° Cohesion (c): 40 psf Test Results 1 2 3 4 Average Moisture Content, % 21.2 21.2 21.2 21.2 21.2 Saturation, % 92.7 92.7 92.7 92.7 92.7 Normal Stress, kips 0.151 0.301 0.603 1 1.206 Peak Stress, kips 0.126 0.234 0.369 1 0.765 LPeak Stress _ Linear (Peak Stress) j try I � I 0.8 Cn L 0.4 0.2 - - I (- -- -�- --�- - 0.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Normal Stress Direct Shear Sladden Engineering Revised 12/03/02 Job Number: Jab Name: Lab ID: Sample ID: Soil Description: Expansion Index ASTM D 4829/UBC 29-2 544-3272 Date: Tract 31249 Tech: Bulk 1 Ey 0-5- Silty Sand Wt of Soil + Rin2: 525.0 Weight of Ring: 179.0 Wt of Wet Soil: 346.0 Percent Moisture: 15% Wet Density, pcf: 104.8 Dry Denstiy, pcf: 91.2 Saturation: 1 47.7 Expansion Rack ff Date/Time 7/10/03 1 7:30 A.M. Initial Reading 0.500 Final Reading 0.500 Expansion Index (Final - Initial) x 1000 0 7/9/03 Jake EI Sladden Engineering Revised 12/10/02 Gradation ASTM C117 & C136 Project Number: 544-3272 Project Name: Tract 31249 Sample ID: Bulls 1 @ 0-5' Sieve Sieve Percent Size, in Size, nun Passing 1" 25.4 100 3/4" 19.1 100 1 /2" 12.7 100 3/8" 9.53 100 #4 4.75 100 #8 2.36 100 #16 1.18 100 #30 0.60 100 #50 0.30 88 4100 0.15 35 #200 0.074 11 100 90 80 70 ou 60 .M cc 50 a 40 30 - 20 - July 9, 2003 10 0 100.0 10.0 1.0 0.1 0.0 0.0 Sieve Size, min Gradation Sladden Engineering Revised 11/20/02 Gradation ASTM C117 & C136 Project Number: 544-3272 Project Na1ne: Tract 31249 Sample ID: Boring 1 a 5' Sieve Sieve Percent Size, in Size, mm _ Passing 1" 25.4 100 3/4" 19.1 100 1 /2" 12.7 100 3/8" 9.53 100 #4 4.75 100 48 2.36 100 #I6 1.18 100 #30 0.60 100 #50 0.30 86 #100 0.15 34 #200 0.074 9 lU 9 81 7( on 6( z; Ca 5C a p 40 30 20 10 0 100.0 July 9, 2003 10.0 1.0 0.1 0.0 0.0 Sieve Size, mm Gradation Sladden Engineering Revised 11/20/02 Gradation ASTMC117&C136 Project Number: 544-3272 Project Name: Tract 31249 Sample ID: Boring 3 @ 10' Sieve Sieve Percent Size, in _ Size, mm Passing ill 25.4 100 3/4" 19.1 100 1/2" 12.7 100 3l8" 9.53 100 44 4.75 100 48 2.36 100 #16 1.18 100 #30 0.60 83 #50 0.30 39 #100 0.15 16 #200 0.074 8 July 9, 2003 Gradation Sladden Engineering Revised 11/20/02 Gradation ASTM C117 & C136 Project Number: 544-3272 July 9, 2003 Project Name: Tract 31249 Sample ID: Boring 7 @ 5' 81 7( to 6C S a: 50 40 30 20 10 0 100.0 Sieve Sieve Percent Size, in Size, mm Passing 1 " 25.4 100 3/4" 19.1 100 1/2" 12.7 100 3/8" 9.53 100 #4 4.75 100 #8 2.36 100 416 1.18 100 #30 0.60 100 #50 0.30 97 #100 0.15 65 #200 0.074 23 10.0 1.0 0.1 0.0 0.0 Sieve Size, mm Gradation Sladden Engineering Revised 11/20/02 APPENDIX B LOGS OF EXPLORATORY TEST PITS & CPT SOUNDINGS Tract No. 31249 La Quinta, Riverside County, California Project No. 2589-CR '91� GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page B- I A - FIELD TESTING AND SAMPLING PROCEDURES The Modified Split -Barrel Sampler (Ring) The ring sampler is driven into the ground in accordance with ASTM Test Method D 3550. The sampler, with an external diameter of 3.0 inches, is lined with 1-inch long, thin brass rings with inside diameters of approximately 2.4 inches. The sampler is typically driven into the ground 12 or 18 inches with a 140-pound hammer free falling from a height of 30 inches. Blow counts are recorded for every 6 inches of penetration as indicated on the log of boring. The samples are removed from the sample barrel in the brass rings, sealed, and transported to the laboratory for testing. Bulk Samples (Large) These samples are normally large bags of earth materials over 20 pounds in weight collected from the field by means of hand digging or exploratory cuttings. B — BORING/TRENCH LOG LEGEND The following abbreviations and symbols often appear in the classification and description of soil and rock on the logs of borings/trenches: SOILS USCS Unified Soil Classification System f-c Fine to coarse f-m Fine to medium GEOLOGIC B: Attitudes Bedding: strike/dip J: Attitudes Joint: strike/dip C: Contact line ........... Dashed line denotes USCS material change Solid Line denotes unit / formational change Thick solid line denotes end of boring/trench (Additional denotations and symbols are provided on the log of borings/trenches) '91� GEOTEK CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v 0 r Test Pit No. TP-I c o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 25 SM Silty f-m SAND, light brown, slightly moist, medium dense 3.3 99.6 19 SM Same as above 9.2 93 Alluvium: 5 20 SM/SP Siltyf-m SAND, light brown, slightly moist, medium dense 12.9 90.5 TEST PIT TERMINATED AT 5 FEET No groundwater encountered Test pit backfilled with soil cuttings 10 IS 20 25 30 ZSample type: ---Ring SIFT Small Bulk ®---Large Bulk No Recovery Q ---Water Table LU V' AL = Atterberg Limits El = Expansion Index SA = Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing E 0 r Test Pit No. TP-2 c o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 16 SM Silty f SAND, olive brown, slightly moist, medium dense 3.1 97.6 6 SM Silty f-m SAND, light brown, slightly moist, loose 7.6 89.0 Alluvium: 5 SP F-m SAND, white -brown, slightly moist, loose 7.4 84.1 5 TEST PIT TERMINATED AT 5 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 ZSample furls: ---Ring SIFT Small Bulk ®---Large Bulk E] ---No Recovery Q ---Water Table LLJ V' AL = Atterberg Limits El = Expansion Index SA = Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v 0 r Test Pit No. TP-3 c o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 25 SM Silty f SAND, light brown, dry to slightly moist, medium dense 3.2 95.8 ---- --------- --------- -------- --------------------------------------------------------------------------------------------- Alluvium: ------------------ ------------------------------ I I SP F-m SAND, light brown, slightly moist, medium dense 5.4 93.4 5 6 SP F-m SAND, light brown, slightly moist, loose 7.1 85.4 TEST PIT TERMINATED AT 5 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 ZSample furls: ---Ring ---SPT---Small Bulk ®---Large Bulk E] ---No Recovery Q ---Water Table LLJ V' AL = Atterberg Limits El = Expansion Index SA = Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v 0 r Test Pit No. TPA c o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 23 SM Silty f SAND, light brown, slightly moist, medium dense 9.5 91.5 ---- --------- --------- -------- --------------------------------------------------------------------------------------------- Alluvium: ------------------ ------------------------------ 8 SP F-m SAND, tan -brown, slightly moist, loose 6.6 90.7 5 10 SP Same as above TEST PIT TERMINATED AT 6 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 Z$dMPle tvtle: ---Ring ---SPT---Small Bulk ®---Large Bulk No Recovery Q ---Water Table w V' AL = Atterberg Limits El =Expansion Index $A =Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v 0 r Test Pit No. TP-5 c o Z U U a E j �` o o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 2 SM Silty f SAND, light brown, slightly moist, loose 5.6 102.3 9 SM Same as above 6.8 95.7 5 Alluvium: 5 SP f-m SAND, white -brown, slightly moist, loose 8.8 84.2 BORING TERMINATED AT 6 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 Z$dmPle tvtle: ---Ring ---SPT---Small Bulk ®---Large Bulk No Recovery Q ---Water Table w V' AL = Atterberg Limits El =Expansion Index $A =Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v 0 r Test Pit No. TP-6 c o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 17 SM Silty f SAND, light brown, slightly moist, medium dense 6.1 93.4 15 --------- SM SIM Same as above - ---- ------------------------------------------------------------------------------- ------------------ ------------------------------ 5 Allluvluv ium:: 15 SM/SP Silty f SAND, light brown, slightly moist, medium dense TEST PIT TERMINATED AT 6 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 Z$dmPle tvtle: ---Ring ---SPT---Small Bulk ®---Large Bulk No Recovery Q ---Water Table w V' AL = Atterberg Limits El =Expansion Index $A =Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v E 0 E TEST PIT No. TP-7 c ~ o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 25 SM Silty f SAND, tan -brown, dry, medium dense 2.6 113.9 ---- --------- --------- -------- --------------------------------------------------------------- --------- Alluvium: -------- 20 SP F SAND, tan -brown, slightly moist, medium dense 9.0 93.7 25 SP F-m SAND, tan -brown, slightly moist, medium dense 10.8 98.4 S TEST PIT TERMINATED AT 5 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 ZSample furls: ---Ring SIFT Small Bulk ®---Large Bulk E] ---No Recovery Q ---Water Table LLJ V' AL = Atterberg Limits El = Expansion Index SA = Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v E 0 E TEST PIT No. TP-8 c ~ o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 25 SM Silty f SAND, light brown, slightly moist, medium dense 4.4 102.7 15 SM Same as above 6.3 96.8 L,SP Alluvium: 14 Silty f SAND, light brown, slightly moist, medium dense 5.7 101.8 5 TEST PIT TERMINATED AT 5 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 ZSample type: ---Ring SIFT Small Bulk ®---Large Bulk E] ---No Recovery Q ---Water Table LLJ V' AL = Atterberg Limits El = Expansion Index SA = Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v 0 r Test Pit No. TP-9 c o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 25 SM Silty f SAND, light brown, moist, medium dense 9.8 101.2 12 SM Same as above 9.3 84.0 5 Alluvium: 25 SP F-m SAND, light brown, moist, medium dense TEST PIT TERMINATED AT 6 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 Z$dmPle furls: ---Ring ---SPT---Small Bulk ®---Large Bulk No Recovery Q ---Water Table w V' AL = Atterberg Limits El =Expansion Index $A =Sieve Analysis RV = R-Value Test CLIENT: PROJECT NAME: PROJECT NO.: LOCATION: Beazer Homes Tract No. 31249 2589-CR La Quinn, CA GeoTek, Inc. LOG OF EXPLORATORY BORING DRILLER: DRILL METHOD: HAMMER: N/A LOGGED BY: Backhoe N/A JD OPERATOR: Morgan RIG TYPE: N/A DATE: 12/28/2020 SAMPLES Laboratory Testing v 0 r Test Pit No. TP-10 c o Z U U a E j �` O o b MATERIAL DESCRIPTION AND COMMENTS 3 Fill: 23 SM Silty f SAND, light brown, slightly moist, medium dense 8.0 101.0 17 St__ Silty f SAND, light brown, moist, medium dense 10.7 87.9 5 Alluvium: 24 SP F-m SAND, light brown, moist, medium dense TEST PIT TERMINATED AT 6 FEET No groundwater encountered Test Pit backfilled with soil cuttings 10 IS 20 25 30 Z$dmPle furls: ---Ring ---SPT---Small Bulk ®---Large Bulk No Recovery Q ---Water Table w V' AL = Atterberg Limits El =Expansion Index $A =Sieve Analysis RV = R-Value Test O1 C N N C W O E u _ io c m c im t f ti y t C c 7 O L Y •C d 3 �a •� N 71 1 ' 1I A'_ .-1 .•i .•i .i .-I N N N N N M M M M M V st st a a in (9) yadaa �m N O O O N l0 CO O N �D 00 O N t0 a0 O N a O O N �' 10 OD O .••i .•i .•i ti ti N N N N N M M M M M v a a a a in 0 N N a N o N w v O L �a 0 N .r .••I .a .ti rl N N N N N M M M M M � a a 7 a in 0 O O N a .D W O N 7 N W O N 't W W O N V .D W O N 't O O O e-I .-I e-I ei e•1 N N N N N M M M M M It a li l ()1) y;daa 0 d U C N U) 47 c 0 V 0 a o n o F- O O N to 00 O N �D 00 O N 7 t0 t0 O N tt N a0 O N �O GO O .••i N H ti rl N N N N N M M M M M C a a of � 1I1 (�1) 43daa co 0 N O a U m N Qj 1 Ln 0 t Q is a-+ O H 3 Y in _ w w y -o�' > j >' U U ' T a _ a�i ari ='=' ari fn >>> in (n (n fn vJ co in fn fn > In U U U U U U rn in In In U U U U U in U U U V U U O N 7 t0 co O N 7 l0 co O N V O co O N 7 l0 W O N V O co O (43) g4daa O N ;I- O LO O N 7 O OW O N V O O O N 7 O W O N 7 l0 O O (44) yldad O N 7 O GO O N 7 l0 co O N 7 lD m O N -;I- l0 W O N 7 lD m O O N 7 ID co O N 7 t0 co O N 7 O co O N 7 t0 co O N V O co O N N N N M M M M M V 7 V 7 V V1 (44) y}dad O N V 0 co O N It lD m O N It lD m O N 7 lD m O N It l0 m O (43) ylda4 O .ti �o co O re M re N O O N O ^ a 0 co O 0 v o o Ln M a,, u U O C o m N T Ln N O co M o N O a U m N '-I Qj M O Lfl L Q is 0 O H Im C N Im c W O U O m C N O N N O H ^ N _r o C) @ Y C 3 N C 3 C O i �o U U N � 0 O' W (7 M u O 10 u a J 3 Y co ca m m m m m m m m m ca m m m m m ca ca m ca � ca ca ca m ca cu ca m m ca ca � t m m m to U y N N In U N In Vl In UJ Vl UJ Vl to - - Vl i- (n to y N to y y y � r- (n In U rn rn c� in rn O in in m in in rn O u)O m= v> > rn rn in w u) cn Co O O > > 0505 c5 ON 7 t0 W O N t l0 coo N V l0 GO O N 7 l0 oW O N V O GO O N N N N N M M M M M V 7 V 7 V Ln (44) g4daa O N ;I- O LO O N 7 O OW O N V l0 O O N 7 O W O N 7 l0 O O (44) yldad O N 7 O GO O N 7 l0 co O N 7 lD W O N -;I- lD M O N 7 lD W O O N 7 tD co O N 7 t0 co O N 7 0 co O N 7 t0 W O N 7 0 co O N N N M M M M M 7 7 7 7 V1 (44) y}dad O N V 0 co O N It lD m O N It O m O N 7 lD W O N It 0 m O (43) ylda4 O ti �o w Ln O M re N O 0 N O ^ a co O 0 v o o Ln M a,, u U O C o m N T Ln N O 3 Y I- y I y n a n U U u°'i 'O T — m — m In IN>>>U � I I _ � � ��> � �U�� m m � U>U m In>InUU UU In InUUInU I I O N 7 10 W O N 7 l0 co O N V l0 GO O N 7 l0 W O N V l0 GO O .--I Ti .-I .-i .-I N N N N N M M M M M V 7 V 7 Ln (44) g4daa O N 7 tD LO O N 7 O OW O N V l0 O O N 7 O W O N 7 l0 O O (44) yldad O N 7 l0 GO O N 7 lD co O N 7 l0 W O N -;I- l0 W O N 7 lD W O O N 7 t0 co O N 7 t0 co O N 7 0 co O N 7 0 co O N 7 0 co O N N N N M M M M M 7 7 7 7 V1 (44) y}dad O N V 0 co O N It lD m O N It O m O N 7 lD W O N It 0 m O (43) ylda4 co -o w Ln O M re N O O N O ^ a 00 O 0 v o o Ln M a,, u U O C o m N T Ln N O Q O O APPENDIX C LABORATORY TEST RESULTS Tract No. 31249 La Quinta, Riverside County, California Project No. 2589-CR 'G, GEOTEK BEAZER HOMES Project No. 2589-CR Updated Geotechnical and Infiltration Evaluation —Tract No. 31249 January 21, 2021 La Ouinta, Riverside County, California Page C- I SUMMARY OF LABORATORY TESTING Classification Soils were classified visually in general accordance to the Unified Soil Classification System (ASTM Test Method D 2487). The soil classifications by GeoTek are shown on the logs of exploratory excavations in Appendix A. Direct Shear Shear testing was performed in a direct shear machine of the strain -control type in general accordance with ASTM Test Method D 3080. The rate of deformation is approximately 0.035 inch per minute. The samples were sheared under varying confining loads in order to determine the coulomb shear strength parameters, angle of internal friction and cohesion. The results of the testing are presented in Appendix C. Expansion Index Expansion Index testing was performed on one representative soil sample. Testing was performed in general accordance with ASTM Test Method D 4829. The results of the testing is provided below. Boring No. Depth (ft.) Soil Type Expansion Index Classification T-3 0-5 Silty Sand 0 Very Low T-7 0-5 Silty Sand 0 Very Low Moisture -Density Relationship Laboratory testing was performed on representative site samples collected during the recent subsurface exploration. The laboratory maximum dry density and optimum moisture content for the samples tested were determined in general accordance with test method ASTM Test Procedure D 1557. The results are included in Appendix C. Sulfate Content, Resistivity and Chloride Content Testing to determine the water-soluble sulfate content, resistivity testing and the chloride content was performed by others. The results of the testing are provided below and in Appendix C. Chloride Sulfate Resistivity pH Boring No. Depth (ft.) ASTM D4327 ASTM D4327 ASTM G 187 ASTM G51 (ppm) (% by weight) (ohm -cm) T-3 0-5 9.1 88.7 0.0463 2,010 T-7 0-5 9.2 134.6 0.0201 1,876 '91� GEOTEK ,,G� G E O T E K Project Name: Beazer Homes Project Number: 2589-CR DIRECT SHEAR TEST Sample Location: Date Tested: Shear Strength: (D = 31.8 ° C = 108.00 psf TP-7 @ 0-5 1 / 15/2021 Notes: I - The soil specimen used in the shear box was a ring sample remolded to approximately 90% relative compaction from a bulk sample collected during the field investigation. 2 - The above reflect direct shear strength at saturated conditions. 3 - The tests were run at a shear rate of 0.035 in/min. co 0 `o U 0 z co J 117 i O N O J E 0 am U M m N 7A7 W F 0 W li �7 a T 0 E LL O ZN O O 0 Q m m m W o o 0 Z LU N ❑ ~ W w o o 0 CV V C QCV 0 Ln � M M M E i 0 N O M E E O U) U 0 _ 0 N Q M Ch 0 E E cB CM 0- E — L ° w 0 0 cm c c L L a)O a) z 3 0 O 1 O 1 ll� I M N N CNO ICJ z O p Q z Lu Lu z O H a � a U Q o N = N O N N T 0 >� 0 L > o U o C� O f 7 N � 0 O_ c LL _ — O �7 a H `W r X W _ N Z v Z O a C0 Z Q a W 7A7 W F 0 W li T 0 C E LL O Z_ LO LO LO 0 N N N Q N N N W O O O Z W o � m 0 Q PZ N W W o o 0 N N QCV 0 Ln O 76� � NI CO CO M O E i 06 � (D O_ M E E o U) U 0 N Q M Ch E E cB CM O_ E - O O 0 0 c N 'U) O O cm C L L a)O C N Z 3 0 O 1 ll� I M O N CNO �f�7 Z O p Q z Lu Lu Z O H a � a U Q o co = N � N N T O >� O L > o U o C� 7 N � O O_ c LL O GEOTEK MOISTURE/DENSITY RELATIONSHIP Client: Beazer Homes Project: TR: 31249 Location: La Quinta Material Type: - Material Supplier: - Material Source: - Sample Location: B3 @ 0-5' Sampled By: EL Received By: DI Tested By: DA Reviewed By: RJ Test Procedure: ASTM D1557 Oversized Material (%): 0.0 120 118 116 114 112 V 110 IL 108 106 z 104 p 102 0>� 100 98 96 94 92 90 Job No.: 2589CR Lab No.: Corona Date Sampled: 1/4/2021 Date Received: 1/4/2021 Date Tested: 1/13/2021 Date Reviewed: 1/14/2021 Method: A Correction Required: Lies ITT IC RIIIIII, 111] 0 41 Q =1 ki Rlk Wd0 =1W_111101*]kih9:nl*i11ATA4 0 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 20 MOISTURE CONTENT, % no ♦ DRY DENSITY (pcf): ■ CORRECTED DRY DENSITY (pcf): ZERO AIR VOIDS DRY DENSITY (pcf) S.G. 2.7 * S.G. 2.8 • S.G. 2.6 Poly. (DRY DENSITY (pcf):) --- OVERSIZE CORRECTED —ZERO AIR VOIDS Poly. (S.G. 2.7) Poly. (S.G. 2.8) Poly. (S.G. 2.6) MOISTURE DENSITY RELATIONSHIP VALUES Maximum Dry Density, pcf 109.0 @ Optimum Moisture, % 12.5 Corrected Maximum Dry Density, pcf @ Optimum Moisture, % MATERIAL DESCRIPTION Grain Size Distribution: • Gravel (retained on No. 4) • Sand (Passing No. 4, Retained on No. 200) • Silt and Clay (Passing No. 200) Classification: Unified Soils Classification: AASHTO Soils Classification: Atterber Limits: Liquid Limit, % Plastic Limit, % Plasticity Index, % GEOTEK,-,-C� MOISTURE/DENSITY RELATIONSHIP Client: Beazer Homes Project: TR: 31249 Location: La Quinta Material Type: - Material Supplier: - Material Source: - Sample Location: 137 @ 0-5' Sampled By: EL Received By: DI Tested By: DA Reviewed By: RJ Test Procedure: ASTM D1557 Oversized Material (%): 0.0 Job No.: 2589CR Lab No.: Corona Date Sampled: 1/4/2021 Date Received: 1/4/2021 Date Tested: 1/13/2021 Date Reviewed: 1/14/2021 Method: A Correction Required: Lies II,yiN]13to] *11.7NI►69111Wd04Wt19[dZ69:II1elliA 4 140 138 136 134 132 v 130 a 128 126 Z 124 p 122 120 118 116 114 112 110 0 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 20 MOISTURE CONTENT, % 99 ♦ DRY DENSITY (pcf): ■ CORRECTED DRY DENSITY (pcf): ZERO AIR VOIDS DRY DENSITY (pcf) S.G. 2.7 * S.G. 2.8 • S.G. 2.6 Poly. (DRY DENSITY (pcf):) --OVERSIZE CORRECTED ZERO AIR VOIDS Poly. (S.G. 2.7) Poly. (S.G. 2.8) Poly. (S.G. 2.6) MOISTURE DENSITY RELATIONSHIP VALUES Maximum Dry Density, pcf 124.0 @ Optimum Moisture, % 9.0 Corrected Maximum Dry Density, pcf @ Optimum Moisture, % MATERIAL DESCRIPTION Grain Size Distribution: Gravel (retained on No. 4) % Sand (Passing No. 4, Retained on No. 200) % Silt and Clay (Passing No. 200) Classification: Unified Soils Classification: AASHTO Soils Classification: Atterberg Limits: Liquid Limit, % LEE Plastic Limit, % Plasticity Index, % rAlCorrosion Project X REPORT S210111B Corrosion Engineering Page 1 Control Soil, Water, Metallurgy Testing Lab Results Only Soil Testing for TR31249 La Quinta January 13, 2021 Prepared for: Anna Scott GeoTek, Inc. 1548 North Maple Street Corona, CA 92280 ascott@geotekusa.com Project X Job#: S210111B Client Job or PO#: 2589-CR Respectfully Submitted, Eduardo Hernandez, M.Sc., P.E. Sr. Corrosion Consultant NACE Corrosion Technologist #16592 Professional Engineer California No. M37102 ehernandezkproj ectxcorrosion.com 29990 Technology Dr, Suite 13, Murrieta, CA 92563 Tel: 213-928-7213 Fax: 951-226-1720 www.projectxcorrosion.com Project X Corrosion Engineering rAlCorrosion Control — Soil, Water, Metallurgy Testing Lab Soil Analysis Lab Results Client: GeoTek, Inc. Job Name: TR31249 La Quinta Client Job Number: 2589-CR Proj ect X Job Number: S210111 B January 13, 2021 REPORT S21011113 Page 2 Method ASTM D4327 ASTM D4327 ASTM G187 ASTM D4972 ASTM G200 SM 4500- S2-1) ASTM D4327 ASTM D6919 ASTM D6919 I ASTM D6919 ASTM D6919 I ASTM D6919 ASTM D6919 ASTM D4327 ASTM D4327 Bore# / Description Depth Sulfates SO4�- Chlorides CI- Resistivity M Ree'd I Minimum pH Redox Sulfide S2- Nitrate N05 Ammonium "'V Lithium Li' Sodium Na' Potassium K� Magnesium Mill Calcium Ca2� Fluoride Fi Phosphate P043- (R) (mg/kg) I (wt%) (mg/kg) (W%) (Ohm -cm) (Ohm -ern) (mv) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) TP-3 0-5 463.3 0.0463 88.7 0.0089 >737,000 2,010 9.1 206 <0.01 109.0 31.0 0.01 149.7 17.4 24.4 165.4 1.3 1.1 TP-7 0-5 200.5 0.0201 134.6 0.0135 113,900 1,876 9.2 206 <0.01 166.0 48.4 0.03 139.9 10.6 15.5 198.8 1.7 3.7 Cations and Anions, except Sulfide and Bicarbonate, tested with Ion Chromatography mg/kg = milligrams per kilogram (parts per million) of dry soil weight ND = 0 = Not Detected I NT = Not Tested I Unk = Unknown Chemical Analysis performed on 1:3 Soil -To -Water extract 29990 Technology Dr., Suite 13, Murrieta, CA 92563 Tel: 213-928-7213 Fax: 951-226-1720 www.projectxcorrosion.com Req Cus Project X Lab 720 wt Sheet Chaco of lion coly Phone: (213) 928-7213 •Fax (951) 226-1720 www.priyexaxcorrusir>tl ctnn Corrosion Engineering Ship Salnpics'ro. 299701'cchnology Dr, Suite 105F, Mumela, CA 92563 ,..• (.,n.nA - Ylnll, Wwu.. wN lnceulMv,v 1 rt. Project X .lob Number 10/ 2 FW1 :- epld -�12�,I`? IMPORTANT- Please complele Project and Sample Idenlifccalion Dala as you would like it to appear in report & include this Corm Willi samples. Company Nam` GEOTEK Inc. Contact Name: Phone No. Mailing Address: ) 548 North Maple St., Corona, CA 92280 Contact Email. ascott(a_geotekusa.com Accounting C'oelact: Invoice Email: ascott@geotekusa.com Project Name: ,r R n 1"2- Client Project No: 25 CIV- 11.0. M: S Day „nand 3 Day ' RUSH - 2 Day, .RUS11 _ ANALYSIS REQUESTED (PleAse circle) ' NOTES 75% "rk-up 100% nark -up _ - I urn Around 11llle: K fJV U�/UU Results By: ❑ Phone O M'ax I% Email ❑Mail ❑ Overnight Mail (charges apply) 7Fm y, Vl C U o¢ '�xQu<� Dale & Received by : 1 f l�QI2,� �'��l"' Default m c :4 o�� a o '�"�"N o A °°� W H$ Nlcthod p<a SPECIAL INSI•RU(TIt)N5: c C O O ev � G• 8 - u OOaCC � $ -a s - Z E E � ° HAI E SAMPLE: 11) - BORE A 0ESC'RIP•r10N uEt`fll (ft) CULLECI'EH O t°a n i'n t� A' a m ¢ <. 4 ' 'n 5 o � hwia a (�K7 ;n-IFon-;�nf�--n171FF71FF--;1—! ` IFF 3 rnr nnnnnnn�nnn - 7n7Fcnnnn7r F :11-7n - 5 nn17-1ED nnnnnnnn - 6 - r-F F-11 Unnnnnnr7n noon, 1nnnnnnnr7 nnnn nnnnnnnr- 9 _ nnl-nnn'ninnnnl-iin'nn -� ll) nnnnEr cE[71F nn tl :F -7cr-n F7❑E7tn IF711 r_-'nnnnnnnfnnnnnn 13 - rannnnnnnnnn❑n❑nn:': - ,, -- ; _:n _ n t _ I IF r- n APPENDIX D INFILTRATION TEST DATA Tract No. 31249 La Quinta, Riverside County, California Project No. 2589-CR 'G, GEOTEK PERCOLATION DATA SHEET Project: CO fu I ,V 1 @ tv" Lo OV IAA h Test Hole No.: Z -1 Depth of Hole As Drilled: 2., f Tested by: J-U Before Test: z f,f job No.: Za.` ,7,, "C4 Date: 2/3 t /2c� After Test: 2, -Cf- Reading No. Time Time Interval (Min) Total Depth of Hole (Inches) Initial Water Level (Inches) Final Water Level (Inches) A In Water Level (Inches) Comments I Tq 2Y 2y 2 : �o ZS Zvi © 21-1 21/ 3 r�� 17 to 2, 2y 21' 4 nor Ao Z4-11 O ZV 21-1 5 � 0 : � � 10 Q 2. 6 S-0 i0 2- 0 2y 2 7 to 2. a �t s 9 10 II 12 13 GEOTEK Client: Beazer Homes Project: Tract 31249 Project No: 2589-CR Date: 12/31 /2020 Boring No. 1-1 Percolation Rate (Porchet Method) Time Interval, At = 10 Final Depth to Water, DF = 48 Test Hole Radius, r = 3 Initial Depth to Water, Do = 24 Total Test Hole Depth, DT = 48 Equation - It = AH (60r) At (r+2Havg) Ho=DT-Do= HF=DT-DF= AH = AD = Ho- HF = Havg = (Ho+HF)/2 = It = .1E 24 0 24 12 GEOTEK'Gr__ Inches per Hour PERCOLATION DATA SHEET Project: job No.: Test Hole No.: -E — 2_ Tested by: Date: Depth of Hole As Drilled: Before Test: After Test: Reading No. Time Time Interval (Min) Total Depth of Hole (Inches) Initial Water Level (Inches) Final Water Level (Inches) 4 In Water Level (Inches) Comments I y, 35�- q p Z N 2 10;00 2vr� 2C/ D 2-9 214 3 [0:Z7 10 2y a 2E( Y 4 to : 3 /0 2 Y Z �/ 5 (� : Lt a Lf q 6 40 �� % 0 G( Y ' y a W � 8 101 Z Y to h 2- 9 10 II 12 13 "G, GEOTEK Client: Beazer Homes Project: Tract 31249 Project No: 2589-CR Date: 12/31 /2020 Boring No. 1-2 Percolation Rate (Porchet Method) Time Interval, At = 10 Final Depth to Water, DF = 48 Test Hole Radius, r = 3 Initial Depth to Water, Do = 24 Total Test Hole Depth, DT = 48 Equation - It = AH (60r) At (r+2Havg) Ho=DT-Do= HF=DT-DF= AH = AD = Ho- HF = Havg = (Ho+HF)/2 = It = .1E 24 0 24 12 GEOTEK'Gr__ Inches per Hour PERCOLATION DATA SHEET Project: job No.: Test Hole No.: r _3 Tested by: Date: Depth of Hole As Drilled: Before Test: After Test: Reading No. Time Time Interval (Min) Total Depth of Hole (Inches) Initial Water Level (Inches) Final Water Level (Inches) 0 In Water Level (Inches) Comments ► 9:�,� 2s Z 0 Zt/ C- 7 2 l0:to;` ZC� 0 q 3 to- S7 to 4 to:Lt7 to 2N 8 '22 (0 2q `t 9 10 II 12 13 GEOTEK Client: Beazer Homes Project: Tract 31249 Project No: 2589-CR Date: 12/31 /2020 Boring No. 1-3 Percolation Rate (Porchet Method) Time Interval, At = 10 Final Depth to Water, DF = 48 Test Hole Radius, r = 3 Initial Depth to Water, Do = 24 Total Test Hole Depth, DT = 48 Equation - It = AH (60r) At (r+2Havg) Ho=DT-Do= HF=DT-DF= AH = AD = Ho- HF = Havg = (Ho+HF)/2 = It = .1E 24 0 24 12 GEOTEK'Gr__ Inches per Hour PERCOLATION DATA SHEET Project: Cofq I t/ !e (0 IA, �,a % irl iR Test Hole No.: ,'-- V Depth of Hole As Drilled: '4 ee Tested by: ,,T P Before Test: 2. Ft" job No.: Z,5 f?q -CA Date: CZ /.71(,20 After Test: Z -r�_ Reading No. Time Time Interval (Min) Total Depth of Hole (Inches) Initial Water Level (Inches) Final Water Level (Inches) 0 In Water Level (Inches) Comments 2 `to 3 10,1)7 /0 zy z 4 10 : to Z t/ 2 ti rf 5 to C/ 6 t o `f ° 1 �/ 2- 7 J0; iQ 2,y {i 7-V ` s q .q I 9 10 II 12 13 G E O T E K Client: Beazer Homes Project: Tract 31249 Project No: 2589-CR Date: 12/31 /2020 Boring No. 1-4 Percolation Rate (Porchet Method) Time Interval, At = 10 Final Depth to Water, DF = 48 Test Hole Radius, r = 3 Initial Depth to Water, Do = 24 Total Test Hole Depth, DT = 48 Equation - It = AH (60r) At (r+2Havg) Ho=DT-Do= HF=DT-DF= AH = AD = Ho- HF = Havg = (Ho+HF)/2 = It = .1E 24 0 24 12 GEOTEK'Gr__ Inches per Hour APPENDIX E LIQUEFACTION ANALYSIS Tract No. 31249 La Quinta, Riverside County, California Proiect No. 2589-CR 'G, GEOTEK GeoTek, Inc. 1548 N. Maple Street Corona, CA 92880 http://www.geotekusa.com LIQUEFACTION ANALYSIS REPORT Project title : Tract 31249, The Village at Coral Mountain Location : La Quinta, CA CPT file: CPT-1 Input parameters and analysis data Analysis method: NCEER (1998) G.W.T. (in -situ): 55.00 ft Use fill: No Clay like behavior Fines correction method: NCEER (1998) G.W.T. (earthq.): 30.00 ft Fill height: N/A applied: Sands only Points to test: Based on Ic value Average results interval: 3 Fill weight: N/A Limit depth applied: Yes Earthquake magnitude M.: 7.14 Ic cut-off value: 2.60 Trans. detect. applied: Yes Limit depth: 50.00 ft Peak ground acceleration: 0.62 Unit weight calculation: Based on SBT K. applied: Yes MSF method: Method based Cone resistance Friction Ratio SBTn Plot CRR plot FS Plot 2 4 6 8 0.8 0.7 0.6 Ln 0.5 0 Y a 0.4 Ln N 0.3 U a U 0.2 0.1 0 ul 2 4 6 8 100 200 300 0 2 4 6 8 10 qt (tsf) Rf (%) Mw=71/1, sigma=1 atm base curve Liquefaction No 2+ 8 l0 2 H r8 30 32 38 40 42 1 2 3 4 Ic (Robertson 1990) 0 20 40 60 80 100 120 140 160 180 200 Qtn,cs N c u, N c 0 m N c N a d U N N ro E 0 Z 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 0 0.2 0.4 0.6 0 0.5 1 1.5 2 CRR & CSR Factor of safety Summary of liquefaction potential 0.1 1 10 Normalized friction ratio (%) Zone A,: Cyclic liquefaction likely depending on size and duration of cyclic loading Zone A2: Cyclic liquefaction and strength loss likely depending on loading and ground geometry Zone B: Liquefaction and post -earthquake strength loss unlikely, check cyclic softening Zone C: Cyclic liquefaction and strength loss possible depending on soil plasticity, brittleness/sensitivity, strain to peak undrained strength and ground geometry CLiq v.2.2.0.32 - CPT Liquefaction Assessment Software - Report created on: 1/6/2021, 7:34:04 AM 1 Project file: G:\Projects\2551 to 2600\2589CR Beazer Homes Tract 31249 The Village at Coral Mountain La Quinta\Cliq\allcpts gw 30ft.clq �TTTT (13) u]da(i v C 00 O� m N 0 tf n 0 t N d moommi �i �LAN M m t � i� N +1 loop& a O N V iD OJ O ti .�i i0 W O N 7 �O OJ O N 7 i0 OJ O N 7 i0 OJ O C 0j) 43daa �..� m L. Gl Q 3 L y d +' a = Ll a° U fC O N V iD W O .N1 W O N 7 O N m O W O N V iD O O r N N N N N M M M M M 7 -Ir 7 U] a (]3) 44daa U O R C O V Li (;j) 4jdaa 11011al IA ?,Jill, RAIIIIIIIII -1 I 4F (]3) 4jdaa 7 N O N L � c o rn w c � � w T Rm C7 > > r� m " 6 ■■❑ o ° 0 -o c 'rn c m m � afOi U Vl U 7 " Li to M E N a w c m rn fO m C N V r�� W cn O U N M vi ❑❑❑ T C O d-- O a N N m N CD O ZY>Tcn� n u O M rn d fo d „ 0 w > a 6 w L 10 t c n a m rnp ° v w w Q c .O ,0 o O' iL H ' U J J M ri C_ .ti C Ln N c c o v Q V mMNmZZ Oa) N 'a u w C V F _m 0 v '+9 '- w ,`.9 o' cn m y m t O w l p L N~ rno w- 5 aw u!'' w- 0 O E � 2 c v (U N J E 100 a0 > vU U Nl cy, a, ¢ T a0 d' OC Ln O .t' C N CD m w LU CqD o 0 R-!IqLn co zzm Ln Y 7 6 R 3 J �tl o ` O w . .- y0i v ? a U w 0 0 E- m y M i i w do c9 0 EvwY�3 ni ai . O 7 Oi N i > YJ C c G'o m w fr QILd W 0-0 U a E w U c m 4j N d O V �TTT m0 � N v �o (;3) 44da4 (;j) 4jda4 mi ll" o 1 11111111filludmilillill MA,— (1j) 4lda4 O M O C O C .-I d M L N O 2 N C � w C7 > > r� m " 6 ■■❑ o ° 0 -o c 'rn c m m � afOi U Vl U 7 " Li to M E N a a) c rn fO m C N V T L> a m cn O U C N M vi ❑❑❑ T C O d-- O Q VI Vf C Vf O 6 Z } } c o }cD U M M . Oa. O 'o T U N > a 6 N L 3L�>;h!;h! o O' iL H' U J J M C_ N C tE o c c o o cD v Q V M M N m Z Z O u v C Vtf F m Q v 49tD - a� O N � O' L p ~ ol O d_ O 2 n L '� 7 3� L •FT N QN u a-. N— O O Lo 2 C N � N J u Ol Nl a o, ¢ T a0 ' cC O •a W W N O O O y p U t0 R zzm �0 LLn n CO Y 6 .9 ' .o £ mooM . '�°m N a L Y i i w'd-! 3m:m oc� 0 E r i ai �n O .2 7 2.2 N c c •o u w j o nr Qwaa� V a N o V c R Ma N N c O V 8 L O c d v V L L O 0 0 O 0 O O V O NV- . co 0" 7 t oD O N 7 �W O N 7 t N O N 7 �W O i�3) 4�da4 IV I I T--7 i O N 7 � W O N 7 ID W O N 7 �D W O N 7 tD oO O N 7 T W O (13) 44da4 (13) 44da4 MEN rwo CAMPlidill (43) 44da4 0 0 N O U c d �a T C O O Q to UI C UI O Q Z } } In i OR U C, 0 M fo -a u u O O N N L f0 o_o. m rn��va�ai Q c d C> a LT F Y U J J (�/) J ti C U) o 42 c m O oM M N m Z Z O v _0 N _ L ra .. v U F 0 N U T C C 3 v > r .. U O L @ 'o N O 3 v vOiL O 0O '-L � 2 c v cu N T (� V m �3 V) m O7 W > a, u 9 ti N. m O, Dl co H o Q .. o w w� o 0 0 W W N 7 N 0 O C U U tU0 N zzca n o 73 c 3' J Ifl 0; v v v d E c o R t o .. E 4b M a ro O 6 a 3 N v of O y0 j Q o � N w 3 ? NL Y y > YJ < Lu a- 0 CL Q o a` U > Li \ (D § 2 f \1 � @ \ � } w - ® co = r qr co co co^mGx�, r r r r r * * * * * � ()ll ud;-a Q)l ud;-a ()ll ud;-a ()ll ud;-,a ■ r\ ,0 T F§ \ 3& \ §\ \ \� ~ 0 —0\ k\ ) /e / \ - \( - -Fu � @x/In { \/ /))( §} //\ƒ $ )E LL 0 oN /\]) j\ _ \ § §fu w - / 5 } E j\ > k Jƒ\ \ / GeoTek, Inc. 1548 N. Maple Street Corona, CA 92880 http://www.geotekusa.com LIQUEFACTION ANALYSIS REPORT Project title : Tract 31249, The Village at Coral Mountain Location : La Quinta, CA CPT file: CPT-2 Input parameters and analysis data Analysis method: NCEER (1998) G.W.T. (in -situ): 55.00 ft Use fill: No Clay like behavior Fines correction method: NCEER (1998) G.W.T. (earthq.): 30.00 ft Fill height: N/A applied: Sands only Points to test: Based on Ic value Average results interval: 3 Fill weight: N/A Limit depth applied: Yes Earthquake magnitude M.: 7.14 Ic cut-off value: 2.60 Trans. detect. applied: Yes Limit depth: 50.00 ft Peak ground acceleration: 0.62 Unit weight calculation: Based on SBT K. applied: Yes MSF method: Method based Cone resistance Friction Ratio SBTn Plot CRR plot FS Plot 2 4 6 8 0.8 0.7 0.6 Ln 0.5 0 Y a 0.4 N 0.3 U a U 0.2 0.1 0 ul 2 4 6 8 100 200 0 2 4 6 8 10 qt (tsf) Rf (%) M„,=71/1, sigma'=1 atm base curve No V ,1 IN 6 6 IN I to IN 10 L2 i 12 IN I 14 16 16 IN J 16 18 x IN 1 18 IN I 20 )2 t t4 I 22 24 t6 �� ; 26 t8 �- � 28 30 I- 30 32 I 32 38 10 12 14 16 18 i0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 1 2 3 4 0 0.2 0.4 0.6 0 0.5 1 1.5 2 Ic (Robertson 1990) CRR & CSR Factor of safety Summary of liquefaction potential 0 20 40 60 80 100 120 140 160 180 200 Qtn,cs N c u, N c 0 m N c N a d U N N ro E 0 Z 0.1 1 10 Normalized friction ratio (%) Zone A,: Cyclic liquefaction likely depending on size and duration of cyclic loading Zone A2: Cyclic liquefaction and strength loss likely depending on loading and ground geometry Zone B: Liquefaction and post -earthquake strength loss unlikely, check cyclic softening Zone C: Cyclic liquefaction and strength loss possible depending on soil plasticity, brittleness/sensitivity, strain to peak undrained strength and ground geometry CLiq v.2.2.0.32 - CPT Liquefaction Assessment Software - Report created on: 1/6/2021, 7:34:05 AM 20 Project file: G:\Projects\2551 to 2600\2589CR Beazer Homes Tract 31249 The Village at Coral Mountain La Quinta\Cliq\allcpts gw 30ft.clq Jul M,-,CNIMM--WMy3J��y��J---r�7�y,w�� :Ti:77ft' :tilT.f: L471 :��;�:•�7---Hf4HC7 M"M l� �MMM lil.ViSi'L�ilJLlil'lJ� :li � LJ i IMMM J�� ------ ---------------� - � ------, ----------------� mmom mimm lmmmmm---� �i III@I logo m=I ��dmi ■ IN lmi ■mmi In 1:111 jig (;3) 44da4 (43) 44da4 RA I� Ar -Mrs' (43) 44da4 Go N O N Q 0 rl N L c c m a� c � � w T C7 > > r� m 6 ■■❑ a o ° 0 N c m T le _� N U Vl U 7 " Li to M E N a a) c rn fO m C N V Y E N C 21 @ W cn O U N M vi ❑❑❑ T C O d-- O a N N m N CD O ZY>Tcn� n O M rn d fo d „ 0 N a 6 N L > t c�a)Ln rnp°'vww Q c 3L�>;h!;h! o O' iL H' U J J M c_ .. C Ln N c c o v Q V r6iM2 a�OZZ O N N 'a V F .10 fl v '+9 '- N tD O N � O' L p ~ OIO d_ O 2 0 L 2 7 3� L AFT N QN O p Lo 2 C N (U N J E Nl .. ¢ T 00 d' OC Ln O .t' C i .a W W-2-T N O O O y p U t0 R zzm�oLn co Y 6 O N E 'c 49 'o^ 0 0 E m y M i 0. 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Maple Street Corona, CA 92880 http://www.geotekusa.com LIQUEFACTION ANALYSIS REPORT Project title : Tract 31249, The Village at Coral Mountain Location : La Quinta, CA CPT file: CPT-3 Input parameters and analysis data Analysis method: NCEER (1998) G.W.T. (in -situ): 55.00 ft Use fill: No Clay like behavior Fines correction method: NCEER (1998) G.W.T. (earthq.): 30.00 ft Fill height: N/A applied: Sands only Points to test: Based on Ic value Average results interval: 3 Fill weight: N/A Limit depth applied: Yes Earthquake magnitude M.: 7.14 Ic cut-off value: 2.60 Trans. detect. applied: Yes Limit depth: 50.00 ft Peak ground acceleration: 0.62 Unit weight calculation: Based on SBT K. applied: Yes MSF method: Method based Cone resistance Friction Ratio SBTn Plot CRR plot FS Plot � f 2 4 6 8 0.8 0.7 0.6 Ln 0.5 0 Y a 0.4 N 0.3 U a U 0.2 0.1 0 u f 2 4 6 8 100 200 0 2 4 6 8 10 qt (tsf) Rf (%) M„,=71/1, sigma'=1 atm base curve No I- rtl 4 4 I- I 8 I- 8 I LO 10 L2 i= 12 L4 I- ,I 14 L6 I- 16 I- t0 I- 20 I )2 I- 22 I t4 24 t6 30 I- 28 30 32 I- �i 32 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 1 2 3 4 0 0.2 0.4 0.6 0 0.5 1 1.5 2 Ic (Robertson 1990) CRR & CSR Factor of safety Summary of liquefaction potential 0 20 40 60 80 100 120 140 160 180 200 Qtn,cs N c u, N c 0 m N c N a d U N N ro E 0 Z 0.1 1 10 Normalized friction ratio (%) Zone A,: Cyclic liquefaction likely depending on size and duration of cyclic loading Zone A2: Cyclic liquefaction and strength loss likely depending on loading and ground geometry Zone B: Liquefaction and post -earthquake strength loss unlikely, check cyclic softening Zone C: Cyclic liquefaction and strength loss possible depending on soil plasticity, brittleness/sensitivity, strain to peak undrained strength and ground geometry CLiq v.2.2.0.32 - CPT Liquefaction Assessment Software - Report created on: 1/6/2021, 7:34:07 AM 39 Project file: G:\Projects\2551 to 2600\2589CR Beazer Homes Tract 31249 The Village at Coral Mountain La Quinta\Cliq\allcpts gw 30ft.clq u ! ( ƒ B 2 2 � k § j u � ()l;g4dO ()l� ud�a ()ll Qdlm �� ■ � � � � �� MEN ()ll udl 3 \ƒ §ro }W \0 \� « @ 7R ! d $ « ■ ■ ❑ « 7 \I / & 2 *#$ /-/ / ■ ■ ■ § E / � 3 « $ \ \ \ ❑ ❑ ❑ t a }mom Cl 2 �«LO / $ _$ l k /£ \\ \ _ { 7]m §& I(23±] /2 L ( ) �\ rr�CD )3$ k® \ 12 u= 2\ tD § 11 t\ � It`s=§ ,) / ƒ £ ®@ f OIL 3: / 2 ]I as /} //\ kb ■ �&0 «K Lulu CD # / §dzm L4d CD ID n co r,4 -0 \ C j § Z - \ / /�}/)) t(2) \\ \§ �_ E A{)a2 \//k �\ k=J3 \ .0 (D a H 3 0 m r v m 0 V) E =�=iIIII�riIl�IIr�r==�I�:=Y=��1111rr�j� MIA 1111��11m "='•,IIII['•1l�III lE��•Lvl`i•C �ia•�ltIl'1['•t i•il[i•� .:`n�:� E • !!! •�i��#r�.!'-'�a•`�•. �i•�-"�lii��i•7!`L-�•l�:L-�1�.`L��`.�..i"• �!:!!`L:�!�:fll • FailF llt� !F l lF�•�F. Fa F. =F:Mk FI iGi��i•�Ei�lyiE��'1i��7�3Gf+�i�f�.�Gf �iGlyiE+�+i�iF�l (43) 44da4 0 O O N O O 0 •� .i .-� .+ .+ .-+ N N N N N M M M M M 7 � 7 � � �/t u o 0 R a ` U o u w R 0 rn O� 0 tf v n O C ro Ln to (4j) 4;da4 }i fl. @ L 0 7 N i+ L 0 a L E C w u C N d C u v E 2 so yr�umovluVr��i+' I (;j) 4jda4 rn�■rnnni � (]3) yldad O 7 lLL N 0 N .ti 7 L C C m m C � w r� o6 - of ■■❑ O O —,a C �VI C m y N C > � N U Vl U 'i - Li 16 ■■■ a a) c rn fO m C N V _ m a m cn O U C N M vi ❑❑❑ T C O d-- O Q VI Vf C Vf O 6 Z } } c n }CD U M 10 fo N L L C -0 d d T �p°'vmw Q C 3Lm>,�,� o O' c_ NCD 0 C V) c c o a) Q V M M N m Z Z O a) Q � 12 ..cu m C V F .10o Q CA '+9 '- N yM ovum cm L,o?3�L v O Eo c v (U N J E a m ao > vU u Nl .. ¢ T co R LU W W N O O O y p U 0 R zzm Ln N Y 6 O_ C N O N . u) 2 V m N E c o £ i moo. L Y M i 'd ^Eam o c9 0 E v+m-'Y �n O .2 7 o y0 N C C c 9'3 m w w j o nr Q'o- W 0-0 V a N o V C a Mn th N L d C O V L O C d V L L O 0 d O O V O N - � W O N 7 t of O N 7 W N CO O i�3) 4�da4 pil ■■■■■ ■■■ I (13) 44da4 (13) 44da4 (13) 44da(i loll owl (43) 44da4 O 0 0 N N a N 0 v a T C O O z»T>R) v v U _O Q N � a N L f0 Ot C) .(u N N N g E E m CO o � O O N 0 ¢ OM M N m Z Z D- .Oi O C N � O N � c O U 10 N f0 O L O N O N O) s m t —LE N a > H O 0 c " o R w w� v o C U U a Z Z y a f O C O N w 0 N y o o .. E v TO o m Ev�Y=� Q of O +O+ C N4J C C C O N v m¢wawa > 3§ 2$ � . . . . . . . . . . . .. . . . .� Li \ G § 2 \ ul 2 \ � _ r ()ll ud;-a Q)l ud;-a ()ll ud;-a ()ll ud;-,a ■ r\ �0 F§ \ 2& \ §\ \ \� ~ 0 —0\ k\ ) /e / \ - \( - - � @x/In { \/ /))( §} //\ƒ $ )E LL 0 oN /\]) �\ _ \ § §rj w - / 5 } { j\ k >Jƒ\ \2 GeoTek, Inc. 1548 N. Maple Street Corona, CA 92880 http://www.geotekusa.com LIQUEFACTION ANALYSIS REPORT Project title : Tract 31249, The Village at Coral Mountain Location : La Quinta, CA CPT file: CPT-4 Input parameters and analysis data Analysis method: NCEER (1998) G.W.T. (in -situ): 55.00 ft Use fill: No Clay like behavior Fines correction method: NCEER (1998) G.W.T. (earthq.): 30.00 ft Fill height: N/A applied: Sands only Points to test: Based on Ic value Average results interval: 3 Fill weight: N/A Limit depth applied: Yes Earthquake magnitude M.: 7.14 Ic cut-off value: 2.60 Trans. detect. applied: Yes Limit depth: 50.00 ft Peak ground acceleration: 0.62 Unit weight calculation: Based on SBT K. applied: Yes MSF method: Method based Cone resistance Friction Ratio SBTn Plot CRR plot FS Plot 2 4 6 8 0.8 0.7 0.6 Ln 0.5 0 Y a 0.4 N 0.3 U a U 0.2 0.1 0 2 4 6 8 z 4 6 100 200 300 0 2 4 6 8 10 qt (tsf) Rf (%) M„,=71/1, sigma'=1 atm base curve No 2� 8 LO L2 L4 L6 L8 >_0 >_2 r8 30 32 38 40 42 184 i0 0 z 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 1 2 3 4 0 0.2 0.4 0.6 0 0.5 1 1.5 2 Ic (Robertson 1990) CRR & CSR Factor of safety Summary of liquefaction potential 0 20 40 60 80 100 120 140 160 180 200 Qtn,cs N c u, N c 0 m N c N a d U N N ro E 0 Z 0.1 1 10 Normalized friction ratio (%) Zone A,: Cyclic liquefaction likely depending on size and duration of cyclic loading Zone A2: Cyclic liquefaction and strength loss likely depending on loading and ground geometry Zone B: Liquefaction and post -earthquake strength loss unlikely, check cyclic softening Zone C: Cyclic liquefaction and strength loss possible depending on soil plasticity, brittleness/sensitivity, strain to peak undrained strength and ground geometry CLiq v.2.2.0.32 - CPT Liquefaction Assessment Software - Report created on: 1/6/2021, 7:34:09 AM 58 Project file: G:\Projects\2551 to 2600\2589CR Beazer Homes Tract 31249 The Village at Coral Mountain La Quinta\Cliq\allcpts gw 30ft.clq u a V 4) a H 0 a s 0 mmmmmmmm mmmmmmmmmmmmmm��I MOCK;, ltilti■k'i�C�°��f�N�[i�Cb■[��►�II W1, MUM M- ul M "ITIV-11MMIMM��d, r! lzwM ■ I mm ■ ■ ■ dllllll ■ m mmmi ■m m mmm ■ ■ I 1 mm■ ■� ■mI 1■■II II ■I El II I 00 goo goo �ra ov 0+ o co '00 �Ln M N O O N N N N 0 M M M M 7 V 7 7 w i�3) 4�da4 N _ C (�3) ulda0 Z m L. i G , L y L +' a _ Ll UOwl a° m s1 O N V �O � O .Ny .�i tD W O N 7 �O OJ O N � •O OJ O N 7 tp � O (] o O R C O V lL -00 ILA A vK A, Al N O N N N N N M M M M M 7 7 7 7 7 1I1 mmm (4j) u4dad 0 N w En M L, o� w � z o ■■❑ a Y O .N C vCmi T U Vl U ' Li 16 ■■■ a c rn fO m C N V m � Y � d •C m G @ W cn O U N M vi ❑❑❑ T C O d-- O a N N m N O O Z Y � cn O M m 10 _O = m N > a 6 N L t c�a) rnp°'vww Q c Z 3L�>;h!;h! o O' iLF- UJJ M c_ .. C V) N c c o a) Q V M M N m Z Z O a) N m O u v C V F .10 0 v '+9 '- N tD m y m O N � O' L p ~ m O d_ O 2 n O p Lo 2 C N (U N J E a W000> (U U Nl ¢ CID .a W W N O O O y p U t0 R zzm �o Ln Ln ca Y 7 6 o O N E c o 0 0 E i w t ^ m o c� 0 E v 7 mY' 3 " ai n O N 17, i > YJ C c �'CL o m es a) j o m QIT W 0-0 U a § � 2 ) IS m E 0 c .m ,2 (A ()l� ud�a 4j 0 � ) k § m � © a0 § 2 � c 3£ g m / k a � u } § 2 Go , � « * * Ah CD � � § E k milli mm-11| PAP, �� r §f « � 7R ! d $ « ■ ■ ❑ « 7 \I / & 2 *#$ /-/ / ■ ■ ■ § E / C \ \ ƒ ❑ ❑ ❑ t a }mom C, 2 �>TLO / $ _$ 1 k £ ) °� / _J \\)}/\ �\ 7](ƒ22 E & I(23±] )/ .e Ln L ( ) CD �\ rr�)3$ k® \ u 2\ § t\ 49 tD ƒ ( ` / ƒ £ ®@ f(2))/ /2 as /} //\kb ■ �&§ «K LULU CD # / §dd]//& co § Z k § \ \ /\) /1}t(2) \\ C,\§ E m t! m � \ ck=Ja23 \ ƒ 0 i�3) 4�da4 0 NNN O N 7 to M O N 7 to M O N 7 to co O 0 N O M �a 0 i�3) 4�da4 ,I - (13) 44da4 (13) 44da4 T c 0 a O ¢va�ima�io z » to > �n C, 0 ED fo -a u u o o m N L f0 o_o. m rn��va�ai Q c d Y '� a ti C U) o c m 0 o CD v ¢ c U MM M N m z z O v N L ra .. v U F 0 N O T C C o v > r _m L @ F 'o N Lm 3 v L O o )-L U') 2 c v cu N T (� v m �3 v) M m W > c U p m rn u < rn O, 01 co �o .T wwO o W W N 7 N 0 O C U U m ro N z z 0] I� O V1 o 73 C R o c i o N - `-' ~ v = � v d E -E R t o .. E m R E = ro Ci (7 a 3 N v of O y0 j .2 N w 3 ? N 4T L Y y > YJ m Qii a w a-0 Q o U o- 41 O a L ad _ 0) E a.d N c s c 4 a L {A � LL 4J 0 O a w O _ O a.d fo E O IL W m O N V t0 OJ O .Ni .�i W O N -Ir tD MCI N 7 lO M O (;j) 4jdaa 0j) 44da4 (4j) 44dea (41) yldad Vim (13) 4jda4 10 O N 2 fu Ln 0 fo LL O 0 7 M t N O O n v u O OU V w 6 N N U C N C C (p U O N N C v w E c - E m �d O > O O_ O LL O C 5: � N O L -fa O U N � Q CD � -u� H(nUd c H f. e � O � i+ c d N a � m •• Q 0-- LL > N ko N E O U T co C i O p U rs, w O O 7 6 J nn a U � .2 N M j C C7 N Qj N Y, O' N J O- U a APPENDIX F GENERAL GRADING GUIDELINES Tract No. 31249 La Quinta, Riverside County, California Proiect No. 2589-CR '91� GEOTEK GENERAL GRADING GUIDELINES APPENDIX F Beazer Homes Page I Tract No. 31249, La Ouinta, California Project No. 2589-CR GENERAL GRADING GUIDELINES Guidelines presented herein are intended to address general construction procedures for earthwork construction. Specific situations and conditions often arise which cannot reasonably be discussed in general guidelines, when anticipated these are discussed in the text of the report. Often unanticipated conditions are encountered which may necessitate modification or changes to these guidelines. It is our hope that these will assist the contractor to more efficiently complete the project by providing a reasonable understanding of the procedures that would be expected during earthwork and the testing and observation used to evaluate those procedures. General Grading should be performed to at least the minimum requirements of governing agencies, Chapters 18 and 33 of the California Building Code, CBC (2016) and the guidelines presented below. Preconstruction Meeting A preconstruction meeting should be held prior to site earthwork. Any questions the contractor has regarding our recommendations, general site conditions, apparent discrepancies between reported and actual conditions and/or differences in procedures the contractor intends to use should be brought up at that meeting. The contractor (including the main onsite representative) should review our report and these guidelines in advance of the meeting. Any comments the contractor may have regarding these guidelines should be brought up at that meeting. Grading Observation and Testing I. Observation of the fill placement should be provided by our representative during grading. Verbal communication during the course of each day will be used to inform the contractor of test results. The contractor should receive a copy of the "Daily Field Report" indicating results of field density tests that day. If our representative does not provide the contractor with these reports, our office should be notified. 2. Testing and observation procedures are, by their nature, specific to the work or area observed and location of the tests taken, variability may occur in other locations. The contractor is responsible for the uniformity of the grading operations; our observations and test results are intended to evaluate the contractor's overall level of efforts during grading. The contractor's personnel are the only individuals participating in all aspect of site work. Compaction testing and observation should not be considered as relieving the contractor's responsibility to properly compact the fill. 3. Cleanouts, processed ground to receive fill, key excavations, and subdrains should be observed by our representative prior to placing any fill. It will be the contractor's responsibility to notify our representative or office when such areas are ready for observation. 4. Density tests may be made on the surface material to receive fill, as considered warranted by this firm. 5. In general, density tests would be made at maximum intervals of two feet of fill height or every 1,000 cubic yards of fill placed. Criteria will vary depending on soil conditions and size of the fill. More frequent testing may be performed. In any case, an adequate number of field density tests should be made to evaluate the required compaction and moisture content is generally being obtained. 'G, GEOTEK GENERAL GRADING GUIDELINES APPENDIX F Beazer Homes Page 2 Tract No. 31249, La Quinta, California Project No. 2589-CR 6. Laboratory testing to support field test procedures will be performed, as considered warranted, based on conditions encountered (e.g. change of material sources, types, etc.) Every effort will be made to process samples in the laboratory as quickly as possible and in progress construction projects are our first priority. However, laboratory workloads may cause in delays and some soils may require a minimum of 48 to 72 hours to complete test procedures. Whenever possible, our representative(s) should be informed in advance of operational changes that might result in different source areas for materials. 7. Procedures for testing of fill slopes are as follows: a) Density tests should be taken periodically during grading on the flat surface of the fill, three to five feet horizontally from the face of the slope. b) If a method other than over building and cutting back to the compacted core is to be employed, slope compaction testing during construction should include testing the outer six inches to three feet in the slope face to determine if the required compaction is being achieved. 8. Finish grade testing of slopes and pad surfaces should be performed after construction is complete. Site Clearing I. All vegetation, and other deleterious materials, should be removed from the site. If material is not immediately removed from the site it should be stockpiled in a designated area(s) well outside of all current work areas and delineated with flagging or other means. Site clearing should be performed in advance of any grading in a specific area. 2. Efforts should be made by the contractor to remove all organic or other deleterious material from the fill, as even the most diligent efforts may result in the incorporation of some materials. This is especially important when grading is occurring near the natural grade. All equipment operators should be aware of these efforts. Laborers may be required as root pickers. 3. Nonorganic debris or concrete may be placed in deeper fill areas provided the procedures used are observed and found acceptable by our representative. Treatment of Existing Ground I. Following site clearing, all surficial deposits of alluvium and colluvium as well as weathered or creep effected bedrock, should be removed unless otherwise specifically indicated in the text of this report. 2. In some cases, removal may be recommended to a specified depth (e.g. flat sites where partial alluvial removals may be sufficient). The contractor should not exceed these depths unless directed otherwise by our representative. 3. Groundwater existing in alluvial areas may make excavation difficult. Deeper removals than indicated in the text of the report may be necessary due to saturation during winter months. 4. Subsequent to removals, the natural ground should be processed to a depth of six inches, moistened to near optimum moisture conditions and compacted to fill standards. 5. Exploratory back hoe or dozer trenches still remaining after site removal should be excavated and filled with compacted fill if they can be located. Fill Placement Unless otherwise indicated, all site soil and bedrock may be reused for compacted fill; however, some special processing or handling may be required (see text of report). 'G, GEOTEK GENERAL GRADING GUIDELINES APPENDIX F Beazer Homes Page 3 Tract No. 31249, La Ouinta, California Project No. 2589-CR 2. Material used in the compacting process should be evenly spread, moisture conditioned, processed, and compacted in thin lifts six (6) to eight (8) inches in compacted thickness to obtain a uniformly dense layer. The fill should be placed and compacted on a nearly horizontal plane, unless otherwise found acceptable by our representative. 3. If the moisture content or relative density varies from that recommended by this firm, the contractor should rework the fill until it is in accordance with the following: a) Moisture content of the fill should be at or above optimum moisture. Moisture should be evenly distributed without wet and dry pockets. Pre -watering of cut or removal areas should be considered in addition to watering during fill placement, particularly in clay or dry surficial soils. The ability of the contractor to obtain the proper moisture content will control production rates. b) Each six-inch layer should be compacted to at least 90 percent of the maximum dry density in compliance with the testing method specified by the controlling governmental agency. In most cases, the testing method is ASTM Test Designation D 1557. 4. Rock fragments less than eight inches in diameter may be utilized in the fill, provided: a) They are not placed in concentrated pockets; b) There is a sufficient percentage of fine-grained material to surround the rocks; c) The distribution of the rocks is observed by, and acceptable to, our representative. 5. Rocks exceeding eight (8) inches in diameter should be taken off site, broken into smaller fragments, or placed in accordance with recommendations of this firm in areas designated suitable for rock disposal. On projects where significant large quantities of oversized materials are anticipated, alternate guidelines for placement may be included. If significant oversize materials are encountered during construction, these guidelines should be requested. 6. In clay soil, dry or large chunks or blocks are common. If in excess of eight (8) inches minimum dimension, then they are considered as oversized. Sheepsfoot compactors or other suitable methods should be used to break up blocks. When dry, they should be moisture conditioned to provide a uniform condition with the surrounding fill. Slope Construction I. The contractor should obtain a minimum relative compaction of 90 percent out to the finished slope face of fill slopes. This may be achieved by either overbuilding the slope and cutting back to the compacted core, or by direct compaction of the slope face with suitable equipment. 2. Slopes trimmed to the compacted core should be overbuilt by at least three (3) feet with compaction efforts out to the edge of the false slope. Failure to properly compact the outer edge results in trimming not exposing the compacted core and additional compaction after trimming may be necessary. 3. If fill slopes are built "at grade" using direct compaction methods, then the slope construction should be performed so that a constant gradient is maintained throughout construction. Soil should not be "spilled" over the slope face nor should slopes be "pushed out" to obtain grades. Compaction equipment should compact each lift along the immediate top of slope. Slopes should be back rolled or otherwise compacted at approximately every 4 feet vertically as the slope is built. 4. Corners and bends in slopes should have special attention during construction as these are the most difficult areas to obtain proper compaction. 5. Cut slopes should be cut to the finished surface. Excessive undercutting and smoothing of the face with fill may necessitate stabilization. 'G, GEOTEK GENERAL GRADING GUIDELINES APPENDIX F Beazer Homes Page 4 Tract No. 31249, La Ouinta, California Project No. 2589-CR UTILITY TRENCH CONSTRUCTION AND BACKFILL Utility trench excavation and backfill is the contractors responsibility. The geotechnical consultant typically provides periodic observation and testing of these operations. While efforts are made to make sufficient observations and tests to verify that the contractors' methods and procedures are adequate to achieve proper compaction, it is typically impractical to observe all backfill procedures. As such, it is critical that the contractor use consistent backfill procedures. Compaction methods vary for trench compaction and experience indicates many methods can be successful. However, procedures that "worked" on previous projects may or may not prove effective on a given site. The contractor(s) should outline the procedures proposed, so that we may discuss them prior to construction. We will offer comments based on our knowledge of site conditions and experience. I. Utility trench backfill in slopes, structural areas, in streets and beneath flat work or hardscape should be brought to at least optimum moisture and compacted to at least 90 percent of the laboratory standard. Soil should be moisture conditioned prior to placing in the trench. 2. Flooding and jetting are not typically recommended or acceptable for native soils. Flooding or jetting may be used with select sand having a Sand Equivalent (SE) of 30 or higher. This is typically limited to the following uses: a) shallow (12 + inches) under slab interior trenches and, b) as bedding in pipe zone. The water should be allowed to dissipate prior to pouring slabs or completing trench compaction. 3. Care should be taken not to place soils at high moisture content within the upper three feet of the trench backfill in street areas, as overly wet soils may impact subgrade preparation. Moisture may be reduced to 2% below optimum moisture in areas to be paved within the upper three feet below sub grade. 4. Sand backfill should not be allowed in exterior trenches adjacent to and within an area extending below a I:I projection from the outside bottom edge of a footing, unless it is similar to the surrounding soil. 5. Trench compaction testing is generally at the discretion of the geotechnical consultant. Testing frequency will be based on trench depth and the contractors procedures. A probing rod would be used to assess the consistency of compaction between tested areas and untested areas. If zones are found that are considered less compact than other areas, this would be brought to the contractors attention. JOB SAFETY General Personnel safety is a primary concern on all job sites. The following summaries are safety considerations for use by all our employees on multi -employer construction sites. On ground personnel are at highest risk of injury and possible fatality on grading construction projects. The company recognizes that construction activities will vary on each site and that job site safety is the contractor's responsibility. However, it is, imperative that all personnel be safety conscious to avoid accidents and potential injury. 'G, GEOTEK GENERAL GRADING GUIDELINES APPENDIX F Beazer Homes Page 5 Tract No. 31249, La Ouinta, California Project No. 2589-CR In an effort to minimize risks associated with geotechnical testing and observation, the following precautions are to be implemented for the safety of our field personnel on grading and construction projects. Safety Meetings: Our field personnel are directed to attend the contractor's regularly scheduled safety meetings. 2. Safety Vests: Safety vests are provided for and are to be worn by our personnel while on the job site. 3. Safety Flags: Safety flags are provided to our field technicians; one is to be affixed to the vehicle when on site, the other is to be placed atop the spoil pile on all test pits. In the event that the contractor's representative observes any of our personnel not following the above, we request that it be brought to the attention of our office. Test Pits Location, Orientation and Clearance The technician is responsible for selecting test pit locations. The primary concern is the technician's safety. However, it is necessary to take sufficient tests at various locations to obtain a representative sampling of the fill. As such, efforts will be made to coordinate locations with the grading contractors authorized representatives (e.g. dump man, operator, supervisor, grade checker, etc.), and to select locations following or behind the established traffic pattern, preferably outside of current traffic. The contractors authorized representative should direct excavation of the pit and safety during the test period. Again, safety is the paramount concern. Test pits should be excavated so that the spoil pile is placed away from oncoming traffic. The technician's vehicle is to be placed next to the test pit, opposite the spoil pile. This necessitates that the fill be maintained in a drivable condition. Alternatively, the contractor may opt to park a piece of equipment in front of test pits, particularly in small fill areas or those with limited access. A zone of non -encroachment should be established for all test pits (see diagram below). No grading equipment should enter this zone during the test procedure. The zone should extend outward to the sides approximately 50 feet from the center of the test pit and 100 feet in the direction of traffic flow. This zone is established both for safety and to avoid excessive ground vibration, which typically decreases test results. 'G, GEOTEK GENERAL GRADING GUIDELINES APPENDIX F Beazer Homes Page 6 Tract No. 31249, La Ouinta, California Project No. 2589-CR TEST PIT SAFETY PLAN Test Pit Spoil pile SIDE VIEW 50 ft Zone of Traffic Direction Non -Encroachment Vehicle Test Pit l parked here J_ 1ple' 10 1 1 Zone of Non -Encroachment 50 ft Zone of Non -Encroachment PLAN VIEW Slope Tests When taking slope tests, the technician should park their vehicle directly above or below the test location on the slope. The contractor's representative should effectively keep all equipment at a safe operation distance (e.g. 50 feet) away from the slope during testing. The technician is directed to withdraw from the active portion of the fill as soon as possible following testing. The technician's vehicle should be parked at the perimeter of the fill in a highly visible location. Trench Safety It is the contractor's responsibility to provide safe access into trenches where compaction testing is needed. Trenches for all utilities should be excavated in accordance with CAL -OSHA and any other applicable safety standards. Safe conditions will be required to enable compaction testing of the trench backfill. All utility trench excavations in excess of 5 feet deep, which a person enters, are to be shored or laid back. Trench access should be provided in accordance with OSHA standards. Our personnel are directed not to enter any trench by being lowered or "riding down" on the equipment. Our personnel are directed not to enter any excavation which; I. is 5 feet or deeper unless shored or laid back, 2. exit points or ladders are not provided, 3. displays any evidence of instability, has any loose rock or other debris which could fall into the trench, or 4. displays any other evidence of any unsafe conditions regardless of depth. If the contractor fails to provide safe access to trenches for compaction testing, our company policy requires that the soil technician withdraws and notifies their supervisor. The contractors representative will then be contacted in an effort to effect a solution. All backfill not tested due to safety concerns or other reasons is subject to reprocessing and/or removal. 'G, GEOTEK GENERAL GRADING GUIDELINES APPENDIX F Beazer Homes Page 7 Tract No. 31249, La Quinta, California Project No. 2589-CR Procedures In the event that the technician's safety is jeopardized or compromised as a result of the contractor's failure to comply with any of the above, the technician is directed to inform both the developer's and contractor's representatives. If the condition is not rectified, the technician is required, by company policy, to immediately withdraw and notify their supervisor. The contractor's representative will then be contacted in an effort to effect a solution. No further testing will be performed until the situation is rectified. Any fill placed in the interim can be considered unacceptable and subject to reprocessing, recompaction or removal. In the event that the soil technician does not comply with the above or other established safety guidelines, we request that the contractor bring this to technicians attention and notify our project manager or office. Effective communication and coordination between the contractors' representative and the field technician(s) is strongly encouraged in order to implement the above safety program and safety in general. The safety procedures outlined above should be discussed at the contractor's safety meetings. This will serve to inform and remind equipment operators of these safety procedures particularly the zone of non -encroachment. The safety procedures outlined above should be discussed at the contractor's safety meetings. This will serve to inform and remind equipment operators of these safety procedures particularly the zone of non -encroachment. 'G, GEOTEK