Building tomorrow: UC Hastings Campus Housing Project in San Francisco
UC Hastings Campus Housing project is in San Francisco, with the Federal Office Building across the street to the south. The project consists of constructing twelve residential levels over a three-story mixed-use podium with two levels below grade. The lowest basement level is about 26 feet below Golden Gate Avenue.
Malcolm Drilling was contracted to design the shoring walls, foundation piles, and the required dewatering schema. Due to variable soil conditions, a combination of soldier beams and lagging, together with Cutter Soil Mix panels, was chosen for the shoring walls. Steel beams in each element were secured with 50-foot long stressed tie-backs. CFA Piles were chosen to carry the building loads. After a successful load test program, 24-inch diameter piles to about 80 feet of depth were installed.
To lower the natural groundwater level from 15 feet below grade through the excavation process, Malcolm installed several 50-foot deep dewatering wells on the inside of the partial cut-off wall. To minimize exterior groundwater drawdown and the possible risk of induced settlements to nearby buildings, additional recharge wells were installed through the shoring wall at a batter