Contents tagged with home

  • Temporary Alaskan Way taking shape near tunnel’s south portal

    For decades, surface Alaskan Way stretched along the downtown waterfront, connecting travelers to the waterfront piers and providing north-south passage through downtown.

    Streetview of Alaskan Way from 2008 showing western position relative to viaduct

    Alaskan Way north of Seneca Street from 2008, via Google Streetview

    Since 2011, the street has been neatly squeezed in between the Alaskan Way Viaduct’s concrete footings. It was shifted to this alignment to clear space for SR 99 tunnel and other construction along the waterfront, but this location was always meant to be temporary. Eventually, the land Alaskan Way currently occupies would need to be cleared to allow for viaduct demolition.

    With demolition now on the horizon, we’ve begun restoring the street to its traditional location. Crews will continue this work over the summer and shift the street back to the west of the viaduct later this year, before the new SR 99 tunnel opens. The preparation for this shift is becoming visible as crews rebuild the roadway.

     

    The restored Alaskan Way will look much like it did the first time around. It will generally have two lanes in each direction, providing access to Colman Dock and waterfront businesses and buildings. Near the viaduct demolition work zone, the road may be narrowed to one lane in each direction, but access to Colman Dock and other properties will always be preserved.

    This configuration will remain in place until the Waterfront Seattle Project builds a new, permanent Alaskan Way in the footprint of the viaduct.

    South portal update

    A little farther south of this stretch of new pavement, an aerial view captures work building the roadways near the tunnel’s south portal. This view from the Columbia Tower shows the alignment of ramps and roadways coming into focus.

    Aerial view of the tunnel south portal

    The future ramps at the tunnel’s south portal cross what is today southbound SR 99 (click for bigger version)

    You can watch this road work from the construction camera we have mounted atop the tunnel’s south operations building. This south portal work is part of the SR 99 Connections Project, which is currently performing utility and roadwork on East Frontage Road South, between South Royal Brougham Way and South Atlantic Street.

    Crews hope to complete as much work as possible before the tunnel is ready to open. The final ramp connections, as you can tell from that map above, will go across the SR 99 mainline. So when the tunnel is ready, we will need to close SR 99 for approximately three weeks to realign the highway and connect it to the tunnel. We do not have a date for the closure yet, but we will be able to provide notice four to six weeks in advance.
     

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    Order: 9.0

  • Kiewit wins contract to demolish the viaduct

    Today, Kiewit Infrastructure West Co. was named the apparent-best-value contractor for the project that will demolish the viaduct, decommission the Battery Street Tunnel and reconnect city surface streets just north of the new SR 99 tunnel.

    The project’s design-build contract, which includes both design and construction services, is valued at $93.7 million. Kiewit submitted the apparent-best-value bid – a combination of points received for their technical proposal and their price.

    Timelines for the work will emerge after the contract is finalized and the contractor receives approval to begin design work. After that point, WSDOT will be able to share more specifics about how demolition and decommissioning will proceed.

    Last year we combined three projects into one in order to save construction time and reduce risk, so this project entails more than just demolishing the Alaskan Way Viaduct. Kiewit will be responsible for:

    • Removing the Alaskan Way Viaduct.
    • Removing the Columbia Street and Seneca Street ramp structures.
    • Decommissioning the Battery Street Tunnel, removing utility and mechanical systems, sealing the entrances and filling the tunnel.
    • Raising Aurora Avenue North to grade between Harrison Street and Denny Way, rebuilding the street, and reconnecting Thomas and John streets across Aurora Avenue North.
    • After viaduct demolition is complete, restoring waterfront roadways, sidewalks, street lighting and other elements to a temporary condition until the City of Seattle builds the new waterfront.

    Demolition cannot start until the tunnel opens to drivers, which could be as soon as this fall.

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    Order: 9.1

  • Sprucing up the north portal

    As we’ve mentioned before, the area surrounding the SR 99 tunnel’s north portal has changed a lot over the course of the project. Nearby cranes indicate that there’s still lots of construction in the area, but Seattle Tunnel Partners’ work is beginning to wind down.

    Last month, following years of utility and other construction, STP began restoring surface streets near the north portal. This work is occurring south and west of STP’s work zone, and includes sidewalk and street restoration.

    Closeup view of two crew members installing form work on Thomas Street
    Crews set up forms in preparation for paving Thomas Street near the tunnel's north portal.

    As roadway restoration continues, crews are building the remaining section of the tunnel’s north operations building. After building out the space that previously housed the tunneling machine’s disassembly pit, crews built the framework for the tunnel’s north operations building. They’re now working on the interior of the building.

    View of the tunnel's north operations building with street restoration in front
    Crews rebuild the tunnel's north operations building behind Thomas Street restoration.

    The latest notification for street restoration is available on our construction notifications page. You can also follow progress at the north portal on our construction cameras page.

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    Order: 9.2

  • One year since Bertha’s final breakthrough

    One year ago, with a roar of water and concrete tumbling, the tunneling machine Bertha broke through into the disassembly pit, completing her 1.7-mile journey under downtown Seattle. It was and remains a remarkable engineering achievement.

    At the time, Seattle Tunnel Partners was working on the double-deck highway inside the tunnel and had completed about half of the upper roadway deck. Since Bertha’s dramatic breakthrough, the machine has been fully disassembled and crews have finished building the roadways and walls inside the tunnel.

    What happened to Bertha?

    The machine needed to be removed from the tunnel so crews could finish the tunnel’s roadways. STP spent four months disassembling the machine, cutting it up into pieces small enough to be lifted out by crane. Roughly 8,300 tons of machinery were hauled out of the disassembly pit, to be repurposed or recycled. Approximately 6,850 tons of metal were sent to be recycled, but pieces of Bertha’s signature cutterhead were donated to the Port of Seattle and cutting tools and the machine’s control panel were given to Seattle’s Museum of History and Industry.

    Bertha is no longer around but you can relive her breakthrough moment with our drone video:

    A year in tunnel progress

    Since Bertha placed the last tunnel ring, crews have made great progress on the structures and systems inside. The roadways and walls inside the tunnel are done, with the last of the roadway panels that make up the tunnel’s northbound (lower) deck placed last month. Crews are hard at work installing the electrical, ventilation and other systems that will make the tunnel functional and safe.

    At the north and south portals, all signs of Bertha’s support equipment and the large pits that bookended the machine’s journey have disappeared. Crews have covered the launch pit and are preparing to build new city streets and intersections. The disassembly pit at the north end has been covered and the final section of the north operations building is taking shape on the surface.

    Other highlights of construction progress since Bertha’s breakthrough:

     

    While the past year has seen impressive progress, there’s still plenty of work left to do. Before the tunnel opens, crews must finish installing the tunnel’s mechanical, electrical and plumbing systems, then test them to ensure they function properly. Stay tuned as we continue to report contractors’ progress building toward the tunnel’s opening, which could happen as early as this fall.

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    Order: 9.3

  • #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