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GEOTECHNICAL Mission Housing Development Corporation Project Background The Mission Housing Development Corporation planned to demolish existing structures on a 4.96-acre site and construct new 3 to 4 story buildings for residential/commercial development. New structures were to be wood frame with above ground podium parking. ERRG was contracted to evaluate the subsurface environmental conditions and the geotechnical properties of the foundation materials at the site to support planned construction. After a review of existing environmental and geotechnical data was completed, additional field investigations were planned and performed. ERRG obtained necessary permits and utility site clearance required for completing field soil investigations on the site. Site explorations included drilling, logging and sampling 7 test borings to depths of approximately 50-feet, and completion of one cone penetrometer test (CPT). Selected soil samples were sent to a certified California laboratory for chemical analyses and a geotechnical laboratory for index parameters and strength testing. Results were used to complete the engineering analysis, which included the following: chemical conditions in subsurface soil and groundwater, mitigation requirements, health and safety requirement during construction, recommended design criteria for foundations; estimates of foundation settlement; identification of potential construction issues; determination of site grading and excavation requirements; evaluation of required fill quality and compaction; determination of site seismicity and any seismic hazards; and evaluation of soil profile type and near source factors based on 1998 San Francisco Building Code. A specific analysis of liquefaction potential, lateral spreading, and settlement of differential compaction was also completed. Project deliverables included a report of investigations and recommendations. |
