Chinatown Station, Central Subway Project

Central Subway San Francisco

Client

City and County of San Francisco Municipal Transportation Agency (SFMTA)

Contractor

CN-1300 Central Subway Stations, Surface, Systems and Trackwork Main Contractor: Tutor Perini

Chinatown Station Contractor: Frontier-Kemper Constructors, Inc.

Consultant for SEM/NATM: Beton- und Monierbau USA, Inc. USA Inc. as consultant for execution of NATM tunnelling works. Technical support, SEM/NATM onsite support by experienced BeMo specialists (Tunnel Manager, Tunnel Engineer and 2 Superintendents on site)

Project location

San Francisco, CA, USA

Start of construction

2015

End of construction

2018

Project total value

approx. 2.5 million €

Geology

Sandstone and weathered sandstone

Technical Data

Subway station in urban environment;
Part of San Franciscos Central Subway Line
Mined cavern beneath Washington/ Stockton Street (between Jackson and Clay Street) in San Francisco’s most populated area;
Main parts are:
• Cross cut cavern
• Platform caverns
• Crossover cavern
• 2 Emergency exits incl 1 emergency shaft
Overall length of the mined cavern: 630 feet;
Overburden between 55 and 85 feet;
Application of sidewall tunnel drift method in combination with continuous presupport with pipe umbrellas

Execution by tunnel excavator, road header attachment, wet shotcrete,
spilling (rebar and grouted pipe spilling), face bolts, dewatering;
tunnel pre-support by pipe roofing

Application of NATM/SEM-side drift tunnel method over total length of Cross cut cavern, platform caverns North & South and Cross over cavern.

Compensation grouting;