Event Date
The Oyster Point development is in construction on a former municipal landfill in South San Francisco. Oyster Point is a peninsula on the San Francisco Bay, and the eastern portion of the peninsula operated as a municipal landfill from about 1956 until it stopped accepting waste in 1970. The site is currently being redeveloped as a life science campus, hotel, and public open space. This presentation will focus on Phases 1 and 2 of the life science campus development.
Subsurface conditions vary drastically across the site, with a portion of the site underlain by shallow bedrock and a portion of the site underlain by up to 40 feet of municipal refuse over 50 feet of soft, compressible clay (Bay Mud) and up to 80 feet of alluvial deposits. Bedrock depth varies from about 0 to 150 feet below the original ground surface. To create level building pads over the steeply sloping site, over 20 feet of engineered fill was placed in some areas. This fill is estimated to cause over 5 feet of long-term settlement. The varying subsurface conditions below the planned buildings and the anticipated settlement led to the need for a foundation system consisting of a combination of shallow and deep foundations. The deep foundations, which extend into bedrock, consist of driven steel HPpiles for Phase 1 and augered cast-in-place (ACIP) piles for Phase 2. In our presentation, we will compare and contrast the use of steel HP-piles and ACIP piles installed for building support. We will present the challenges and solutions in the design and installation of each pile type through municipal waste landfill, along with the results of the load test programs. Additional topics will include design of piles and utilities to account for long-term settlement and a variably corrosive environment and refuse spoils management.
Biography
Justin Ray has worked at Langan for the last 12 years after graduating from UC Berkeley with his Master’s degree in Geotechnical Engineering. With Langan, he has provided geotechnical engineering services for numerous projects throughout the Northern California, including commercial and residential developments for mid- and high-rise buildings, and education and medical facilities. Justin is the geotechnical lead of Langan’s Sacramento office.