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Compensation Grouting

Chinatown Station

Service Performed
Conceptual, preliminary, detailed design of underground caverns, egress tunnels and mined shafts; scheduling and cost estimating; risk management; specifications and tender. Onsite support during construction.
Estimated cost
Commencement - Services
March 01, 2016
Completion - Services
March 31, 2018
425 Market Street Suite 1700
San Francisco, CA 94105
United States
Geology description

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.

Geology types

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. In order to minimise excavation volume and optimise cost and schedule, the ventilation ducts are located below the platform level, and routed into the headhouse.

Construction methods
Special Construction techniques
Barrel Vault Method, Compensation Grouting
Tunneling under
Groundwater control
Tunnel length
Excavation and support sequence of large urban cavern
Large urban cavern under construction
Excavation and support sequence - longitudinal section
Chinatown, San Francisco Dense Urban Neighborhood
Overall Station Layout, Headhouse and Caverns (Rendering by JV)
Station Cavern with Center Platform, Mezzanine and Ventilation Ducts
Proposed Mitigation Measures for adjacent Buildings
Complex 3D Finite Element Analyses
Project number
Final cost
$1.6 billion USD
Completion date