ITEM 23 ATTACHMENT 6 - Project Plans

December 21, 2022 Job No. 4031.101 Page 5 BERLOGAR STEVENS & ASSOCIATES SEISMIC HAZARDS Earthquake Zones of Required Investigation are produced by the California Geologic Survey (CGS). The site is located within the Dublin Quadrangle. The western portion of the site (adjacent to Foothill Road) is located in an area earthquake induced landsliding as shown on Plate 4. 6.3.1. LIQUEFACTION Based on the high blow counts for material encountered above and below groundwater, it is our opinion that the potential for liquefaction at the site is low. 6.3.2. LANDSLIDING During our field exploration we did not identify areas of instability. Materials encountered in our test pits generally consisted of competent soils and bedrock. 7. CONCLUSIONS AND PRELIMINARY RECOMMENDATIONS GENERAL Based on the information collected during this investigation and the results of our analyses, it is our opinion that proposed development is feasible from a geotechnical engineering perspective, provided that the conclusions and recommendations in this geotechnical investigation are incorporated into the project design. EXISTING FILL -SOUTHWESTERN PORTION OF PROPERTY After completion of our test pits and identifying existing fill on the southwestern portion of the property, we contacted Pacific Aerial to use photogrammetry to try to roughly estimate grades in 1959 prior to earthwork. The topography provided was then compared with the latest topography provided by Ruggeri Jensen Azar (RJA). The results of the comparison are presented as fill depth isopachs on the attached Plan. This Plan shows there is some amount of fill from the top of the knoll down to the base at about 392 elevation. CUT SLOPES An approximately 50-foot-high cut slope with a 4 horizontal to 1 vertical gradient is proposed on the southwestern portion of the site. It is our opinion that this slope can be constructed as planned.