Contents tagged with home

  • Nov. 21 project update: Bertha nearing the tunnel’s deepest point

    Seattle Tunnel Partners passed the 60 percent mark of tunnel boring last week. As of this morning, crews had mined 5,774 of 9,270 feet and installed 880 of 1,426 concrete tunnel rings. 
    Bertha, the SR 99 tunneling machine, is located near Virginia Street, between First and Second avenues. With the top of the cutterhead now approximately 210 feet below the surface, crews are nearing the deepest point of the tunnel drive. 
    STP will continue mining and other construction activities through Wednesday before securing the work zone for the holiday weekend. Work will resume on Monday.
    Happy Thanksgiving from the Alaskan Way Viaduct Replacement Program team.
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  • Nov. 7 project update: Girders arrive for future off-ramp

    Large bridge girders began arriving Monday in the work zone near the stadiums. Crews will install the girders this week on the new bridge that will serve as the off-ramp from northbound SR 99 to South Dearborn Street after the tunnel opens to traffic.
    The bridge will include 14 girders in all. The four largest girders will be installed overnight Tuesday, requiring crews to close the left lane of northbound SR 99 between South Holgate Street and Railroad Way South from 9 p.m. Tuesday to 5 a.m. Wednesday.
    You can see regularly updated images of the girder installation on our south-end construction cameras.
    Off-ramp girders
    Crews are installing bridge girders near the stadiums as part of the South Dearborn Street Off-ramp Bridge Project. This post explains how this "flexible" bridge will use new technology to stand up to earthquakes. This folio provides a detailed technical description of the materials being used.
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  • Nov. 3 project update: Bertha passes the one-mile mark

    Seattle Tunnel Partners passed the 5,280-foot mark of the SR 99 tunnel on Thursday morning. Less than 4,000 feet now separates the front end of Bertha, the SR 99 tunneling machine, from the receiving pit (links to YouTube) near the Space Needle where Bertha will emerge at the end of tunneling. Bertha’s cutterhead is located more than 200 feet below First Avenue, just north of Stewart Street.
    The one-mile point in Bertha’s journey also marks the tunnel route’s departure from the ground beneath First Avenue. While First veers northwest at Stewart Street, Bertha will continue pushing north toward the receiving pit. By passing Stewart Street, Bertha entered Zone 7 of the tunnel drive
    How do crews steer the five-story-tall tunneling machine toward the finish line some 4,000 feet to the north? We asked Jerry Roberge, one of Bertha’s operators, that very question. Jerry’s answer, along with exclusive footage from inside the tunnel, can be seen in the video below.
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  • #99closure feature: Drone footage inside the SR 99 tunnel

    Just a few days before the SR 99 tunneling machine started tunneling under the Alaskan Way Viaduct, the Washington State Department of Transportation flew a video-equipped drone through the SR 99 tunnel to show Seattle Tunnel Partners’ construction progress. There has been continued interest in seeing what has been built below ground and this video gives a glimpse of the tunnel as well as the nooks and crannies of the complex tunneling machine.

    On an average day, the tunnel is … more

  • The choreography of a concrete pour

    This week, at the south entrance to the bored tunnel, Seattle Tunnel Partners is pouring concrete for a section of the future southbound highway. On one hand, the pouring of concrete (also known as a "concrete placement”) is nothing extraordinary – it’s a common occurrence on a project that will use enough concrete to build nine football stadiums. But their frequency belies the complex choreography that goes into executing each pour successfully. Since concrete plays … more

  • Take a virtual tour of SR 99 tunnel construction

    Keeping the public informed about our work to replace the Alaskan Way Viaduct is an important part of what we do every day. Our goal is to give you as much access as possible to this amazing project, which is why we regularly post updates, photos and videos of our progress. We even offer walking tours from our information center, Milepost 31, to a viewing platform that overlooks the pit where tunneling began in summer 2013.

    Unfortunately, there’s one frequently received request … more

  • New narrated video explains Bertha repair work

    As reported elsewhere on our website, work to access and repair the SR 99 tunneling machine is coming along. We’ve heard from some people that Seattle Tunnel Partners’ repair plan is hard to picture. Enter STP’s Chris Dixon, who was nice enough to narrate a video that explains what crews are doing to resume tunneling by March 2015. Watch it on YouTube or download a WMV file.

    Other resources 

    Seattle Tunnel Partners repair work plan (pdf 4.8 Mb) … more

  • What we’re doing to keep traffic moving during the four-day SR 99 closure

    We’ve been asking you to do your part to reduce congestion when SR 99 closes for four days starting Friday night, Aug. 22. That includes things like changing your commute habits and choosing an alternate way to get around.

    But what are we, the agencies tasked with keeping traffic moving during this closure, doing to help? Quite a bit, actually. Here’s a roundup of some of the steps we’re taking to help you and your fellow commuters through the closure.

    Washington … more

  • Traffic shift underway on State Route 99 near the stadiums

    Less than three years ago, crews demolished the southern mile of the Alaskan Way Viaduct. When they did, they shifted traffic onto a new section of State Route 99 south of downtown Seattle.

    Much of that new section of SR 99 is permanent, but the piece west of the stadiums is temporary. This curving stretch of road takes drivers around the SR 99 tunnel construction site and connects to the remaining section of the viaduct near South King Street. It’s nothing fancy, but it’s … more

  • Celebrate Bike Month on our new path

    Just in time for Bike Month, we opened a new permanent connection between the on-street bike lanes south of South Atlantic Street and the shared-use path from South King Street. Here’s a map that shows the improvements, which include:

    A dedicated, 14-foot-wide shared-use path with improved paving.

    Improved lighting.

    A separate northbound and southbound path for more efficient navigation.

    Signs warning of vehicles crossing the intersection of … more