UPDATE: Incident #NJudah train has been placed onto the sidetrack. Delay at Church and Duboce has cleared. OB https://t.co/vSxfPFyn2C (More: 40 in last 24 hours)

Central Subway Construction Update 11/6/15

Friday, November 6, 2015 - 12:00am

Thank you for your interest in the Central Subway Project, which is a significant project in the history of San Francisco's public transportation network. This project is the first underground line to link the north and south corridors of the city, and will provide a direct connection to major retail, sporting and cultural venues while efficiently transporting people to jobs, educational opportunities and other amenities throughout San Francisco.

This is an exciting time as the San Francisco Municipal Transportation Agency's | Central Subway team works to construct a vital transportation link that, when open in 2019, will improve connectivity for the city. 4th and King intersection, site of the 8 day trackwork installation beginning November 6. Central Subway | Project Advancement

November 6- November 16, 2015

This notice provides a construction update and a look ahead for what to expect in the areas where we are building four new stations along the alignment. You’ll find information about work activities, traffic and transportation impacts taking place over the next two weeks at SoMa, Yerba Buena|Moscone, Union Square and Chinatown.

Construction schedules, bus routes, and stop locations are subject to change due to unforeseen conditions. Signs will be posted at affected stops to advise of service changes.

Our thanks goes out to the businesses, residents, shoppers, commuters, and all those who are touched by the Project, for their continued engagement as we work to extend the city's public transportation system.

The Central Subway Team

A trench marks where utility upgrading is being conducted north of Brannan on 4th Surface Station, Trackwork and Systems The second phase of trackwork and transit signal priority upgrades  begins Veteran's Day Weekend, 10p.m. Friday November 6 and continues through Saturday night, November 14.  This is a 24 hour operation.  . The first phase of this project was completed over Labor Day Weekend.  The completion of this work will be a major milesstone in the construction of the Central Subway.  For more information, please visit the SFMTA's 4th and King site.

For the work along 4th Street between Bryant and King streets, a surface station will be built between Bryant and Brannan Streets. The construction team is working on upgrading utilities and trackwork on 4th Street between the portal at Bryant Street and the connection with the existing system at King Street.

Current activities include utilities relocation, Muni manhole, duct bank, water line work from the water department, auxiliary water supply system, and sewer structure modification work. Another trench marks further utility work on 4th, just north of Freelon Alley
  A dump truck works removing gravel from the construction site
  Overview

  • Installation of trackwork and signal priority transit upgrades
  • Installation of Muni manhole and duct bank
  • Utility installation
  • Installation of high pressure water line

Details

What:  Installation of trackwork and transit signal priority upgrades
Time:  24 hour operation
When:  Friday, November 6 through Saturday, November 14

What: Installation of Muni manhole, duct bank, utility installation
Time: 7a.m. - 4p.m.
When: Monday to Friday
Where: Brannan Street between 4th Street and 5th, Street, Townsend Street to King Street

What:  Low pressure water line/AWSS
Time:  7a.m. - 4p.m.
When:  Monday to Friday
Where:  4th Street and Welsh Street

  What to expect

  • Work may involve saw-cutting, potholing and jack-hammering on the roadway and sidewalk
  • Sidewalk access may be limited
  • Access will remain open for pedestrians and businesses
  • Muni Service Impact
  • For Muni service impacts for the November 6 through 4th construction
  • Parking and Traffic Impact
    • Parking will be unavailable along the work area
    • Westbound lane on King Street closed during working  hours
    • Northbound lane on 4th Street closed during working hours

Steel walers span the headhouse structure with soil excavated from the station box underneath Yerba Buena | Moscone Station

4th Street from Howard to Folsom

Work along 4th Street between Howard Street and Folsom Street consists of construction of the underground Yerba Buena | Moscone Station. The cut and cover method known as a "top-down" or "bottom-up" approach involves construction of a box frame structure within a trench excavation that is subsequently backfilled.

Current activities include excavation and rebar placement.
 

A large excavator bucket was used to remove soil excavated from the headhouse and station box structures Temporary steel supports span across the Yerba Buena | Moscone Station headhouse site, at the corner of Folsom and 4th Streets Overview
 

  • Excavation
  • Rebar placement

Details

What: Excavation
Time:  7a.m.-7p.m.
When:  Monday to Friday
Where: Howard  Street to Folsom Street

What: Rebar placement
Time:  8:30a.m. to 4:30 p.m.
When:  Saturday
Where: 4th Street
  What to expect

  • Clementina Street is closed at 4th Street
  • The sidewalk on the west side of 4th Street is closed
  • Parking and Traffic Impact
    • One lane of traffic open on the east side of 4th Street

Holes in the Union Square Garage roof act as access points for work below Union Square | Market Street Station

For the duration of the project, you'll see work along Stockton Street between Ellis Street and Post Street. The construction of an underground Union Square|Market Street Station uses the cut and cover method known as a "top-down" or "bottom-up" approach involves construction of a box frame structure within a trench excavation that is subsequently backfilled.

Current activities include roof deck installation, demolition of the northwest corner of the Union Square Garage, utility relocation and compensation

Single-lane traffic continues until the November construction moratorium on Geary at Stockton for pile installation.

At the southeast corner of the Union Square Garage workers are reconstructing a vehicle access ramp. A worker uses a small jackhammer to remove material where a new, reinforce concrete ramp will be constructed inside the Union Square Garage. Overview

  • Installation of roof deck
  • Utility relocation and support
  • Excavation at north concourse
  • Partial demolition and remodeling of Union Square Garage
  • Rebar installation

Details

What: Roof deck, utility, excavation, rebar installation and partial demolition of Union Square Garage
Time: 7a.m.-11p.m.
When: Monday to Saturday
Where: Ellis Street to Post Street
* Construction hours may be 24 hours a day, Monday to Saturday, Sunday work may be required What to expect

  • Local deliveries may access Maiden Lane from Post Street
  • Sidewalk access may be limited at times
  • Muni Service Impact
    • The bus stop for the 38 Geary Route on Geary Boulevard at Stockton Street is discontinued until further notice. Board bus on Geary Boulevard at Powell Street.
  • Parking and Traffic Impact
  • Ellis Street is closed to through traffic between Stockton and mid-block until mid-November. 
  • When Ellis reopens, vehicles will not be able to turn onto Market Street as part of the Safer Market Street project.  For more information, please visit https://www.sfmta.com/projects-planning/projects/safer-market-street
  • Stockton Street between Ellis Street and Post Street is closed to vehicular traffic 

A worker monitors the crane when soil is excavated Chinatown Station The construction of an underground Chinatown Station uses the sequential excavation method (SEM) along Washington Street and Stockton Street. The SEM provides a high degree of flexibility during construction and makes it possible to control virtually all kinds of ground conditions, thereby greatly reducing the risks of construction. This method of tunnel construction is used worldwide for small to large openings in a variety of ground types ranging from rock to soil.

Sprayed concrete (shotcrete) and other supporting elements immediately after exposure, followed by installation of additional steel and shotcrete support elements until a safe stable opening is created will be used.

Current activities include utility relocation, excavation of the headhouse, and trenching and connection of dewatering wells. 
  A full bucket of excavated soil is lifted out of the Chinatown Station headhouse exterior Workers use steel I-beams installed to temporarily reinforce the headhouse interior as a catwalk to access around the periphery of the excavation Overview

  • Excavation of station site
  • Connection of dewatering wells
  • Installation of temp bracing

Details

What: Excavation of station site
Time: 7a.m.- 7p.m.
When: Monday to Saturday
Where: Stockton Street and Washington Street

What:  Connection of dewatering wells
Time:  7a.m -5p.m.
When: Monday to Friday
Where: Stockton Street, Sacramento Street to Jackson Street

What:  Installation of temp bracing
Time:  7a.m -5p.m.
When: Monday to Friday
Where: Stockton Street

  What to expect

  • Sidewalk access may be limited at times
  • Parking and Traffic Impact
    • Detours will be in place between the hours of 9p.m.and 5a.m. during dewatering wells installation
    • Parking will be unavailable during PG&E work
    • Washington Street:
      • remains closed between Stockton and Trenton streets
      • is converted into a two-way street between Powell Street and the construction zone

Connecting People. Connecting Communities.

Contact Us: If you have questions about construction or the Central Subway Project you can email us at central.subway@sfmta.com or call us at 415-701-4371.

For More Information: The Central Subway team posts frequent project updates on a variety of social media outlets. To find out more about the project and construction progress, follow us on Facebook, Twitter, or Flickr, and check out our blog.

Construction schedules are subject to change.