Wednesday, August 6, 2008

I-405 weekend closures...Wilburton tunnel removal

If you live in the Puget Sound region and haven't heard about the Wilburton Tunnel removal and I-405 closures, now's the time to find out more. We will close the southbound lanes on I-405 in Bellevue this weekend to safely remove the tunnel above the freeway. With lane closures like this, traffic could get bad. We're talking 13-mile backup bad. So planning alternate routes or having a staycation is advised.

So how, exactly, do we remove a tunnel? Think of the crunchiest cereal you've ever eaten-Captain Crunch, Grape Nuts, or Cinnamon Toast Crunch. Now imagine what your teeth are crunching is concrete. The specialized machinery being brought for this job has jaws that are capable of crushing four-feet thick concrete. That's crunchy.

Fun facts about this weekends work
Located just north of the I-405/I-90 interchange the Wilburton Tunnel runs about 360 feet long and 70 feet wide.

While this looks like a small tunnel, demolition numbers are surprisingly large:
  • The total weight of debris being moved from the Wilburton Tunnel is equivalent to the weight of 14 Statue of Liberties.
  • 20 million pounds (10,000 tons) of concrete will be crunched into smaller chunks and hauled away—about the weight of three Space Needles.
  • 1.5 million pounds of rebar will be extracted. This is equivalent to the weight of four Boeing 747 airplanes.
  • 1 million pounds (500 tons) of sand will be placed on the roadway each Friday night, acting as a buffer to protect the roadway from falling debris.
Crews will use about a dozen pieces of equipment to remove the Wilburton Tunnel:
  • Two 15,000 ft-lb breakers, each capable of crushing four-feet thick concrete will break, or crunch, down the tunnel into small concrete chunks.
  • Six hydraulic excavators with specialty attachments (concrete crunchers, breakers, and “bucket and thumb”) will crunch the tunnel and help remove debris
  • Bobcats and a front-end loader will help remove debris
  • A hydraulic hammer will crush the tunnel


After Friday at 11 p.m. you won't be able to go under the tunnel, but there are detours in place. Check the Web site for the latest updates on the tunnel removal progress.

6 comments:

dargilac said...

I'm sure if every driver frustrated by the tunnel was given a hammer, the demolition project would be finished today :)

Dave in Redmond said...

Looking at the photos posted on Flickr it looks like possibly the entire tunnel could be demolished in this one weekend. Is that the plan? If so, what work will be done the during the next two weekend closures?

Jennifer said...

Hi--This is Jen from the I-405 team.
Crews continued to make progress over last night, and are demolishing the east wall of the tunnel today until about 6 p.m., when work will shift to a cleanup operation so we can reopen all lanes of southbound I-405 by 5 a.m. Monday.

Crews will stop at what is known in construction lingo as a cold joint. This is the point where there is clean concrete and no exposed rebar.

Work is on schedule. Our contractor tells us the toughest work is yet to come, though. Check out the construction journal for continual status updates: http://www.wsdot.wa.gov/Projects/i405/112thAvetoSE8th/update.htm

Greg Phipps said...

Hi Dave,

We're on schedule for the work performed this weekend. Although the top of the tunnel has come down easily, the sides of the tunnel are thicker so they're coming down slower. Once on the ground, we need to clean up the debris, sweep the road and re-stripe lanes, so we've got a tall order ahead of us.

Stay tuned to the I-405 - Wilburton Tunnel Removal Status Updates for the latest tunnel removal information.

MACK DADDY said...

I always call it "the scary tunnel" because people always slow down or slam on their brakes approaching the tunnel, even during "non-peak" hours. I'm glad they are demolishing the scary tunnel!

Anonymous said...

Good grief. You know in a couple of years, you're going to be spending another $30 million to rebuild the railway line you just severed.... and worse, closing the highway again in order to do so!

No long-term planning, that's what's wrong with this country.