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GEOTECNIA Project Number: 060805 2888 Darius Way, San Leandro October 27,2006 Page I INTRODUCTION Puroose A geotechnical study has been completed for the proposed new residence at 2888 Darius Way in San Leandro, California. The main purposes of this study have been to (1) evaluate the geologic and geotechnical conditions at the site, and (2) develop geotechnical criteria for design and construction of the proposed improvements at the site. Scooe The scope of our services was outlined in our Professional Service Agreement dated August II, 2006. Our work i~luded performing a site reconnaissance visit; reviewing selected geotechnical data, reports by others provided by the Client, and published geologic, landslide, fault, and seismic hazard maps of the site vicinity; drilling, logging, and sampling eight borings at the site to depths of 4 to 19.5 feet below the ground surface; collecting two bulk samples of the subgrade soils along the access road; perfonning Atterberg limits laboratory tests on selected soil samples and R-value laboratory tests on the bulk samples; conducting geotechnical interpretations and engineering analyses; and preparing this report. This report contains the results of our study, including findings regarding surface and subsurface conditions; conclusions pertaining to site-specific geotechnical conditions and geologic hazards; and geotechnical recommendations for design and construction of the proposed improvements. The site location relative to existing streets is shown on Plate 1 - Site Location Map. The locations of the borings relative to existing site features and the proposed new residence are shown on Plate 2 - Boring Location Map. The logs of the borings are displayed on Plates 3-10 - Logs of Borings B-1 through B-8. Explanations of the symbols and other codes used on the logs are presented on Plate 11 w Soil Classification Chart and Key to Test Data, and Plate 12 - Engineering Geology Rock tenns. Results of three Atterberg limits tests are presented on Plate 13 - Plasticity Chart. Plates 1-13 are included in Appendix A. R~f~r~nces consulted during the course of this study are listed in Appendix B. Details regarding the field exploration and laboratory testing programs appear in Appendix C. Proiect Descriotion The subject lot has been graded as part of the deyelopment of the eastern end of Darius Way. A soil and geologic investigation was prepared by _I~I!~~~a~<?l1, Inc.. in 1989 for the proposed subdivision. The higher, northern portion of the site is on a cut slope, while the lower, southern portion of the site includes a fill slope and an unpaved access road connecting the proposed building area to the Darius Way cul-de-sac. The current plan is to construcla main house, a carriage house, a pool house, a driveway, a fire-truck turning area, and a retaining wall along the downslope (southern) side of the building area, as shown on Plate 2. The project will also