Owner
The San Francisco Municipal Transportation Agency - SFMTA
Client
PB / Kwan Henmi / Michael Willis JV
Cost
$1.6 billion USD
Timeframe
April 2016
— February 2018
Services performed
Preliminary and Detailed Design of SEM Station Caverns in Urban Environment, including Excavation & Support, Waterproofing, and Final Lining.
Description
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.
Geology
The geology ranges from soft clay - Bay Clay to stiļ¬ sands - Colma Sands, and competent to highly fractured rock - Franciscan formation. The groundwater table is generally above the cavern springline.
Location
San Francisco, CA, USA
Highlights
- Design of large SEM caverns
- Historic and High-rise Buildings next to Caverns
- Variable Ground Conditions
Rendering of Platform Cavern
Finite Element Model of Station
Excavation and Support Sequence of Large Urban Cavern
Large Urban Cavern Under Construction
Excavation and Support Sequence - Longitudinal Section
Overall Station Layout, Headhouse and Caverns - Rendering by JV
Chinatown, San Francisco Dense Urban Neighbourhood
Station Cavern with Centre Platform, Mezzanine and Ventilation Ducts
Proposed Mitigation Measure for adjacent Buildings
Complex 3D Finite Element Analysis