Malcolm Drilling’s Role in San Francisco’s 30 Van Ness Development
30 Van Ness is a 47-story mixed-use development in San Francisco’s new “Hub” area, featuring 234,000 sq. ft. of office space in a nine-story podium and a 37-story residential tower above three basement levels. The project, centrally located in San Francisco, includes constructing a 37-story residential tower over a nine-story office podium with excavation depths reaching 45 feet below the static groundwater level. Malcolm Drilling was involved in the excavation, installation of deep wells and recharge wells, design and build of a temporary work trestle, and construction of the shoring cut-off wall.
Given the deep excavation reaching into the Zone of Influence (ZOI) for BART (local subway), Malcolm utilized isolation casings for deep foundation elements to transfer structural loads through the ZOI. The design incorporates a double casing assembly, allowing the inner casing to move freely within the ZOI relative to the outer isolation casing.
Malcolm also designed and installed perimeter shoring using an 83-foot deep Cutter-Soil-Mix (CSM) Shoring wall with two internal steel bracing levels. Due to the site’s small footprint, a temporary trestle on drilled shafts supported the 300-ton service crane and the site office.
Malcolm installed 55-foot deep dewatering wells inside the CSM shoring wall and 80-foot deep recharge wells outside the excavation to meet BART’s specifications for maintaining the exterior groundwater level.
