Contents tagged with home

  • Access pit camera update

    We’ve received a number of questions recently regarding access pit camera 2, which provides an overhead view of the circular pit (pdf 2.5 Mb) Seattle Tunnel Partners is building to access and repair the SR 99 tunneling machine. The camera has been offline twice in the past month. The first time was intentional, as archaeologists investigated a shell deposit discovered in the pit by crews on Oct. 23. The camera view was restored on Nov. 8 after the investigation was complete. 
    Then, due to a loss of power, the camera stopped working on Nov. 13. The power outage has not yet been resolved, but please be assured that we recognize that the construction cameras are a great way for the public to track STP’s progress, and we’re working to resolve the issue as quickly as possible.
    To give you a sense of STP’s progress over the past several days, here’s a photo of the site taken on Nov. 18. The access pit is now 65 feet deep – just over halfway down to its final depth of 120 feet.    
    November 18 photo of SR 99 tunnel access pit
    When the issue with the camera is resolved, we’ll let you know. In the meantime, thanks for your patience.


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  • Access pit excavation resumes

    State archaeologists gave Seattle Tunnel Partners clearance to resume access pit excavation on Sunday, Nov. 2. The decision was reached Saturday, Nov. 1, following a required investigation of the shell deposits discovered on Oct. 23 by crews digging the pit.
    Archaeologists believe the shell deposits are the product of commercial shellfish activities carried out by early Seattleites around the turn of the 20th century, but more information will be obtained after a full laboratory analysis is completed. Still, after exercising due diligence, and following state and federal laws through coordination with the Department of Archaeology and Historic Preservation, tribes and King County, excavation was allowed to proceed.
    No one wants to stop work. We understand and share the urgency of the public in wanting to resume tunneling as quickly and safely as possible. But we also have an obligation to follow state and federal laws, and exercise due diligence when dealing with potentially significant discoveries. That’s why we have a very prescriptive process in place for dealing with this type of incident. We’d like to extend our gratitude to DAHP, the tribes and King County for expediting their review so crews could resume excavation as quickly as possible. 
    Dealing with unanticipated discoveries
    In the days since the shell deposits were unearthed, we’ve received quite a few questions about what laws govern the process for investigating unanticipated archaeological finds. If a potentially significant resource is discovered, WSDOT stops work to investigate, as required by state and federal laws. As part of the project’s federal approvals, WSDOT committed to an Unanticipated Discovery Plan. A standard condition for all WSDOT construction projects, this plan requires that potentially significant archaeological resources or deposits found during construction – basically, any potential archaeological materials that were not identified in pre-construction review – be evaluated.
    Throughout the investigation, WSDOT archaeologists consult with DAHP and other stakeholders such as tribes and local governments to determine if the resource is culturally or historically significant. If it isn’t, work resumes. If it is, WSDOT looks at options to avoid the resource, minimize the effects to the resource, or mitigate for the effects to the resource.
    In this case, all parties agreed that if the shell deposits prove to be significant from a regulatory perspective, the investigation we conducted, and the report we’re in the process of completing, constitutes sufficient mitigation. That is, our efforts to characterize the archaeology to date will provide a scientific and historical record of what was found that offsets the destruction of the deposits from excavation of the access pit.  
    Construction cameras
    Due to the potentially sensitive nature of the investigation, we temporarily disabled our access pit construction cameras on Oct. 28. We expect to have them back online soon so the public can watch Seattle Tunnel Partners crews as they work to get Bertha moving again. (UPDATE: As of Nov. 8, the access pit cameras are back online) 

    Previous updates

    Oct. 28, 2014 update – Archaeological investigation begins at the access pit

    Oct. 28, 2014 update – Access pit cameras temporarily disabled

    Oct. 20, 2014 update – Access pit excavation is underway

    Oct. 10, 2014 update – Seattle Tunnel Partners lowering groundwater near the access pit

    Sept. 8, 2014 update – With pile work done, Bertha inches forward

    Aug. 28, 2014 update – Construction of the access pit's underground walls wraps up, preparation for dewatering begins

    Click here to see a full archive of progress updates

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  • 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

  • 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