The San Francisco Municipal Transportation Agency - SFMTA
PB / Kwan Henmi / Michael Willis JV
— February 2018
Preliminary and Detailed Design of SEM Station Caverns in Urban Environment, including Excavation & Support, Waterproofing, and Final Lining.
Chinatown Station is the Northern Terminus of the Third Street Light Rail Project, which is located in a dense urban neighbourhood, underneath a busy street and directly adjacent to numerous old buildings, as well as one high-rise building. The station encompasses a Cut-and-Cover headhouse for passenger entry, three large station caverns and an emergency egress shaft. To minimise excavation volume and optimise cost and schedule, the ventilation ducts are located below the platform level, and routed into the headhouse.
The geology ranges from soft clay - Bay Clay to stiﬀ sands - Colma Sands, and competent to highly fractured rock - Franciscan formation. The groundwater table is generally above the cavern springline.
San Francisco, USA