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;