Construction Update | December 7-16
Inside TBM Mom Chung, the new tunnel curves as it passes below Market Street. Our tunneling crews successfully and safely completed the crossing under BART last week.
We completed an important construction milestone last week as our tunneling contractor and TBM Mom Chung successfully and safely tunneled under Market Street and the existing BART and Muni tunnels. The TBM is now under Stockton Street in Union Square.
During the next 10 days, Central Subway work will continue at sites in SoMa, Union Square, Chinatown and North Beach. This post contains brief updates about what is happening in each neighborhood. For more detailed information, click here or on the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.
Southern SoMa (Harrison to King/Berry): We expect to begin potholing for utilities on 4th Street between Bryant and King the week of Dec. 16. At the tunnel launch box on 4th Street between Harrison and Bryant, tunneling continues with both TBMs.
Northern SoMa (Market to Harrison): We have reestablished our work zone on 4th Street between Folsom and Harrison, in front of Pacific Bicycle. Work here involves improving ground conditions as the second TBM, Big Alma, passes underground. Work is currently paused at 4th and Stevenson, to resume when Big Alma reaches that area. At 4th and Folsom, we are building a covered walkway adjacent to the construction site on 4th Street and Clementina.
Union Square: Construction is now paused on Stockton Street, resuming in January. Work will continue on Ellis Street during December to allow for ground improvements related to tunneling.
Chinatown: Last week our crews closed a portion of Washington Street just west of Stockton Street to allow for utility work and the construction of underground Chinatown Station walls. Tentative: On Clay and Jackson streets adjacent to Stockton Street, the contractor may be performing underground borings some nights next week.
North Beach: Construction is now paused on Columbus Avenue, resuming in January. Work will continue on private property at 1455 Stockton and 1731-1741 Powell to ensure we are ready for the arrival of the first TBM in the spring. One morning next week, heavy equipment will be delivered to the construction site at the 1455 Stockton parking lot early in the morning, before regular working hours.
We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.
