Contents tagged with home

  • Early warning: Four-day closure of SR 99 coming in late August

    In August, crews working on the North Access contract near the SR 99 tunnel’s north portal will demolish the bridge on SR 99 over Broad Street. Not sure what bridge we’re talking about? Don’t worry. Even the most seasoned SR 99 commuter may not realize they are crossing a bridge at Broad Street.

    That bridge, and Broad Street itself, must be completely transformed to make room for the future connection to the tunnel’s north portal and on- and off-ramps at Harrison and Republican streets.

    Crews have already begun to fill in Broad Street with recycled concrete from the former roadway. Once we close this section of SR 99 to traffic, crews will bring in heavy equipment and demolish the old bridge in about 12 hours. They’ll then spend the next two days adding more fill material to make the new roadway level with the existing lanes of SR 99. After paving the new SR 99 roadway, crews will stripe the lanes and reinstall barriers. Once all of this is completed, SR 99 will reopen.

    Closure information
    Demolishing a bridge and building a new road in its place isn’t easy work. It is especially challenging on a major highway through Seattle. To minimize disruptions to drivers, crews will replace this portion of SR 99 in a mere four days. Drivers should plan ahead for SR 99 closures from Friday night, Aug. 22 to Wednesday morning, Aug. 27. Closure details can be found here

    There’s a lot of other work that will happen on SR 99 during this closure as well, including utility work at Harrison Street, concrete panel replacement in SODO, expansion joint repairs on the viaduct near the Seneca Street off-ramp and removal of ivy and other maintenance on the viaduct.

    We will continue to share information to help drivers plan ahead and get around during the closure.

     
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  • Contractor announces details of repair work plan for the SR 99 tunneling machine

    Bertha has always been big. The focus now is on rebuilding Bertha and making her better, according to a new repair work plan unveiled Monday, June 16, by Seattle Tunnel Partners, our design-build contractor for the SR 99 Tunnel Project.

    STP’s work plan (pdf 4.8 Mb), which is illustrated in a new animation (view on YouTube or download WMV file), contains four major repair and enhancement elements:

    • Replacing the damaged seal system with a more robust system
    • Replacing the main bearing
    • Installing enhanced monitoring systems
    • Adding steel to strengthen the machine and accommodate the new seal system


    Other major enhancements of the work plan include:

    • Widening the openings at the center of the cutterhead
    • Improving the soil conditioning injection system
    • Installing bit- and wear-resistant steel on the cutterhead
    • Extending the length of the agitator arms in the mixing chamber


    STP will provide WSDOT with additional supporting information about rebuilding the machine in the coming months, in accordance with the design-build contract, to demonstrate how the repairs will meet the contract’s performance and technical requirements, including:

    • An analysis demonstrating that the machine’s structure can withstand all loads from the surrounding ground and its own operation
    • Seal design details and background calculations
    • Design of revised conditioner injection systems and cutterhead openings
    • Updated operations plan including enhanced instrumentation and monitoring for key machine components
    • Complete testing program for all modified machine components prior to restart of mining


    Bertha is currently stopped approximately 60 feet underground between South Jackson and South Main streets. As owner of the machine, STP is responsible for ensuring it functions properly at all times. STP is currently building the underground walls of a circular pit (pdf 2.5 Mb) crews will use to access and repair the machine.

     

    Links to STP’s plan for repairing Bertha

     

    Previous updates 

    May 13, 2014 update – Construction of access pit’s underground walls now underway

    May 8, 2014 update - With environmental review complete, access pit construction begins in earnest

    April 29, 2014 update - A summary of change orders on the SR 99 Tunnel Project

    April 21, 2014 update - SR 99 tunneling machine to resume digging in March 2015

    April 3, 2014 update - Setting the stage for Bertha's repairs

    Click here to see a full archive of progress updates

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  • 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

  • The SR 99 tunnel contract you’ve never heard of

    You may have noticed more construction along State Route 99, just north of the Battery Street Tunnel. That work is part of the SR 99 Tunnel Project, but it has its own name – the North Access Project. It’s also being built under a completely different contract than the one we have with Seattle Tunnel Partners, the contracting team responsible for most of the tunnel work. A map of major contracts within the program can be found here (pdf 1.1 Mb).

    Our contractor for the North … more

  • SR 99 tunnel’s north portal taking shape near the Space Needle

    A few blocks northeast of the Space Needle, crews are building the north portal of the SR 99 tunnel. It’s a huge piece of the overall tunnel project, but it’s largely invisible to the thousands of people that pass by it every day.

    About the only place you can see the north portal taking shape is from the viewing deck of the Space Needle because most of the construction is underground, inside a pit that’s every bit as impressive as the launch pit where Bertha, the SR 99 … more

  • Lots to see inside the tunnel launch pit

    You can’t see much from the surface, but there’s a lot of work happening in the launch pit where tunneling started last summer. Last week, Seattle Tunnel Partners removed the giant steel frame that Bertha, the SR 99 tunneling machine, pushed against to start her drive into the tunnel. The frame is now on its way to be recycled.

    Work is also well underway to dismantle the temporary concrete tunnel rings Bertha installed to give her additional leverage at the start of her … more

  • Keeping the Alaskan Way Viaduct safe until the tunnel opens

    We're looking forward to opening the tunnel to traffic and demolishing the Alaskan Way Viaduct. It’s the reason we come to work each day. But until we take down the viaduct, it’s our job to protect it and keep it safely open to drivers.

    And so this weekend, as they do four times every year, WSDOT crews will inspect the viaduct. They’ll start by closing the structure to traffic on Saturday and Sunday. Then they’ll begin a methodical weekend of work measuring … more

  • Building a better transportation system

    The Washington State Department of Transportation is working to build a safer, more durable, effective transportation system for our citizens. All across the state – from Bellingham to Vancouver, Forks to Spokane – we manage hundreds of important transportation projects each year to upgrade or replace aging roads and bridges, increase capacity for carrying people and freight, and create more environmentally sustainable travel options for the public.

    You’ve been hearing … more

  • The beauty of barging

    On Nov. 23, crews started barging soil from the tunnel dig site to a disposal facility near Port Ludlow. Adding barges to the fleet of trucks hauling away soil has greatly improved the speed and efficiency of the tunneling operation.

    The reason for that is simple: Bertha is moving a lot of soil – soil that has to be taken away to make room for more soil. If crews removing it can't keep up with Bertha, the bin where the soil is stored gets full and the machine has to slow down. … more