07 September 2012 ~ 1 Comment

Construction Update: New traffic configurations in SoMa, North Beach as tunnel preparation progresses

This block of Columbus Avenue in North Beach is temporarily restored for traffic at the end of each work day. With autumn just around the corner, tunnel pre-construction continues to move forward in SoMa, Union Square and North Beach. As tunneling contractor Barnard Impregilo Healy JV completes work along the alignment, new traffic configurations are […]

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17 August 2012 ~ 0 Comments

Construction Update: Tunnel preparation underway at four sites, Union Square utility relocation substantially complete

Tunnel pre-construction work is now underway on Ellis Street. The tall machine shown here on the right is used to perform ground stabilization work known as jet grouting. Tunnel pre-construction has continued to ramp up in recent weeks as tunneling contractor Barnard Impregilo Healy mobilized at two new sites along the project alignment: Around Union […]

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27 July 2012 ~ 0 Comments

Construction Update: Tunnel contract work starts next week in Union Square area

Construction of a major excavation known as a launch box is underway on 4th Street between Bryant and Harrison streets. At nearly 500 feet long, 50 feet wide and up to 40 feet deep, the launch box will take up most of the block. In the next three weeks, work to prepare for tunneling will […]

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15 June 2012 ~ 8 Comments

Construction Update: Launch box and headwall construction proceeding in SoMa, road restoration progressing in Union Square

Construction at the site of the tunnel launch box, shown here, ramped up this week.  Construction to prepare for the Central Subway tunnel ramped up this week, and the new sidewalks on the west side of Stockton Street are almost completely restored. Here’s what to expect in the next three weeks as tunnel preparation continues and the Union […]

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11 June 2012 ~ 2 Comments

Starting in SoMa: On 4th Street between Folsom and Howard, construction to prepare for tunneling

Construction is now underway on 4th Street near the intersection with Folsom Street. Construction to prepare for the installation of below-ground walls, called headwalls, has begun on 4th Street between Folsom and Howard streets, the site of the future Yerba Buena/Moscone Station. The work currently underway includes potholing and utility relocation. Headwall installation, which involves major […]

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07 June 2012 ~ 1 Comment

Preparing for the Central Subway Tunnel: Major Work Commencing Next Week

At the site of the tunnel launch box, crews are constructing shallow, below-ground walls to prepare for the major upcoming excavation. Next year, a pair of tunnel boring machines (TBMs) will begin excavating the Central Subway tunnel, building the backbone of Muni’s extension of the T Third Line through vibrant and bustling SoMa, downtown, Union […]

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