Latest updates on the Alaskan Way Viaduct Replacement Program
Recently, our team detected approximately one inch of ground settlement near the pit Seattle Tunnel Partners is building to access and repair the SR 99 tunneling machine. Settlement was also detected on the Alaskan Way Viaduct and some of the buildings that we are monitoring; the amount of settlement lessens in the surrounding area. Our experts are still analyzing data and conducting daily inspections of the viaduct, but the initial settlement we reported publically on Dec. 5 has since … more
At the construction site for the SR 99 tunnel’s north portal, imagining the future is getting easier. While it all looks like one project, north portal construction is comprised of two separate contracts. Roughly everything south of the tunnel entrance near Harrison Street is part of the main tunnel contract being completed by Seattle Tunnel Partners. North of the tunnel entrance, crews working for Atkinson Construction are building the lanes and ramps that will connect … more
Since SR 99 tunnel construction started, big cranes have become a familiar sight on the west side of the Alaskan Way Viaduct. Recently, two new cranes have risen up, and they are like redwoods in a forest of pine trees. The “little” crane can lift up to 300 metric tons and stands 180 feet high. Its big brother can lift up to 600 metric tons and tops out at 236 feet high. That’s more than four times the height of the viaduct, or about the same height as the clock tower … more
She’s like Bertha, but faster. Much, much faster.
Meet “Bertha’s Last Stand,” runner-up at the 2014 Red Bull Soapbox Race in Seattle. Though not affiliated with or supported by WSDOT, a group of soapbox racers from Machias, Washington were so inspired by Bertha that they designed and built their own soapbox tunneling machine to drill through the competition. One of 36 teams that built and raced homemade cars through Seattle’s Pioneer Square neighborhood, … more
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
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.
Seattle Tunnel Partners repair work plan (pdf 4.8 Mb) … more
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
You may have heard that SR 99 will close for four straight days starting Friday night, Aug. 22. It’s the longest full closure of SR 99 in Seattle since crews demolished the southern mile of the Alaskan Way Viaduct in 2011. While this is probably not welcome news for travelers, it is a sign of progress at the tunnel’s north portal.
The 2011 demolition of the viaduct cleared the way for construction of the tunnel launch pit and the commencement of tunneling. During this … more
Seattle Tunnel Partners, our contractor for the SR 99 Tunnel Project, is remodeling the giant concrete box where they assembled, tested and launched Bertha, the world’s largest tunneling machine.
Fittingly, Bertha’s launch pit is massive – 400 feet long and 80 feet wide. It was 80 feet deep, but it’s a little shallower now due to the remodel, which is turning the pit into part of the future State Route 99.
Remodeling the launch pit isn’t too much … more
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