PRELIMINARY GEOTECHNICAL AND FAULT RUPTURE HAZARD INVESTIGATION APN 380-250-023 NW OF PRIELIPP RD & ELIZABETH LN WILDOMAR, CALIFORNIA PREPARED FOR STRATAEQUITY GROUP, INC. SAN DIEGO, CALIFORNIA MARCH 24, 2014 PROJECT NO. T2539-22-02B Project No. T2539-22-02B March 24, 2014 Strata Equity Group, Inc. 4370 La Jolla Village Drive, Suite 960 San Diego, California 92122 Attention: Mr. Eric Flodine Subject: PRELIMINARY GEOTECHNICAL AND FAULT RUPTURE HAZARD INVESTIGATION APN 380-250-023 NW OF PRIELIPP RD & ELIZABETH LN WILDOMAR, CALIFORNIA Dear Mr. Flodine: In accordance with your request, we have performed a preliminary geotechnical investigation and fault rupture hazard investigation of a 20-acre parcel located northwest of the intersection of Prielipp Road and Elizabeth Lane in Wildomar, California. The accompanying report presents the findings of our study, and our preliminary conclusions and recommendations pertaining to the geotechnical aspects of future design and construction. If you have any questions regarding this report, or if we may be of further service, please contact the undersigned. Very truly yours, GEOCON WEST , INC . Lisa A. Battiato Kenneth E. Cox CEG 2316 GE 2793 LAB:KEC:GK:JT:lb (1 pdf) Addressee TABLE OF CONTENTS 1. PURPOSE AND SCOPE ...................................................................................................................... 1 2. SITE AND PROJECT DESCRIPTION................................................................................................ 2 3. GEOLOGIC SETTING......................................................................................................................... 2 4. SOIL AND GEOLOGIC CONDITIONS ............................................................................................. 3 4.1 Younger Alluvium/Topsoil (Qal) ............................................................................................... 3 4.2 Colluvium (Qcol)........................................................................................................................ 3 4.3 Pauba Sandstone (Qps)............................................................................................................... 3 5. GROUNDWATER ............................................................................................................................... 4 6. GEOLOGIC HAZARDS ...................................................................................................................... 4 6.1 Surface Fault Rupture................................................................................................................. 4 6.2 Seismicity ................................................................................................................................... 5 6.3 Estimation of Peak Ground Accelerations.................................................................................. 6 6.4 Seismic Design Criteria .............................................................................................................. 7 6.5 Liquefaction Potential................................................................................................................. 9 6.6 Seismically-Induced Settlement ................................................................................................. 9 6.7 Landslides................................................................................................................................... 9 6.8 Earthquake-Induced Flooding .................................................................................................. 10 6.9 Tsunamis and Seiches............................................................................................................... 10 6.10 Subsidence................................................................................................................................ 10 7. CONCLUSIONS AND RECOMMENDATIONS.............................................................................. 11 7.1 General...................................................................................................................................... 11 7.2 Soil and Excavation Characteristics ......................................................................................... 12 7.3 Grading..................................................................................................................................... 14 7.4 Shrinkage.................................................................................................................................. 17 7.5 Foundation Design.................................................................................................................... 17 7.6 Miscellaneous Foundations ...................................................................................................... 18 7.7 Lateral Design........................................................................................................................... 19 7.8 Concrete Slabs-on-Grade.......................................................................................................... 19 7.9 Preliminary Pavement Recommendations................................................................................ 20 7.10 Swimming Pool/Spa ................................................................................................................. 22 7.11 Retaining Wall Design.............................................................................................................. 22 7.12 Retaining Wall Drainage .......................................................................................................... 23 7.13 Elevator Pit Design................................................................................................................... 24 7.14 Elevator Piston.......................................................................................................................... 25 7.15 Temporary Excavations............................................................................................................ 25 7.16 Surface Drainage ...................................................................................................................... 26 7.17 Plan Review.............................................................................................................................. 26 Geologic Review................................................................................................................................. 33 Lineament Analysis............................................................................................................................. 33 Field Investigation............................................................................................................................... 34 Summary of Findings.......................................................................................................................... 34 Conclusions......................................................................................................................................... 36 LIMITATIONS AND UNIFORMITY OF CONDITIONS LIST OF REFERENCES MAPS, TABLES, AND ILLUSTRATIONS Figure 1, Vicinity Map Figure 2, Geologic Map and Site Plan Figure 3, Regional Fault Map Figure 4, Regional Seismicity Map Figure 5, Probability of Exceedance Figure 6, Retaining Wall Drainage Details Figure 7, Retaining Wall Footing Details Table 1, Faults within 60 Miles of the Site – Deterministic Site Parameters APPENDIX A FIELD INVESTIGATION Figures A-1 through A-4, Boring Logs Figures A-5 through A-11, Test Pit Logs APPENDIX B LABORATORY TESTING Figure B1, Direct Shear Test Results Figure B2, Laboratory Test Results Figure B3, Corrosivity Test Results APPENDIX C FAULT RUPTURE HAZARD INVESTIGATION Plate C-1, Fault Trench Logs PRELIMINARY GEOTECHNICAL AND FAULT RUPTURE HAZARD INVESTIGATION 1. PURPOSE AND SCOPE This report presents the results of a preliminary geotechnical and fault rupture hazard investigation for an approximately 20-acre parcel in the City of Wildomar. The site is APN 380-250-023 and is located immediately northwest of Prielipp Road and Elizabeth Lane. The site is depicted on the Vicinity Map, Figure 1. The purpose of the investigation was to evaluate subsurface soil and geologic conditions underlying the parcels, and based on conditions encountered to provide preliminary conclusions and recommendations pertaining to the geotechnical and geologic aspects of future design and construction. The scope of our investigation included a site reconnaissance, review of available geologic literature, geotechnical field exploration, laboratory testing, engineering analysis, fault trench excavations, geologic logging, and the preparation of this report. Geotechnical drilling was performed on November 7 th and 13 th , 2012 by excavating four 8-inch diameter borings with a CME 75 drill rig. The borings were excavated to depths between 20.5 and 25.25 feet below the existing ground surface. Seven test pits were excavated in areas which were inaccessible to the drill rig. The test pits were excavated utilizing a four-wheel drive backhoe equipped with a 30-inch bucket to depths between 2.5 and 8 feet. The approximate locations of the exploratory borings and test pits are depicted on the Geologic Map, Figure 2. A detailed discussion of the geotechnical field investigation, including boring and test pit logs, is presented in Appendix A. Laboratory tests were performed on selected soil samples obtained during the investigation