Demolition experts bashed a notorious section of the old Nalley Valley viaduct into rubble Thursday, kicking off the latest phase of work on Pierce County’s busiest intersection.
Using giant machinery equipped with hydraulic hammers, workers rapidly dropped an elevated section of the old bridge between southbound Interstate 5 and westbound state Route 16, a curved and steeply canted connector that challenged drivers for decades.
“They come down so fast, and they take so long to build,” said Claudia Cornish, a Washington State Department of Transportation spokeswoman, shouting to be heard over the jackhammer din.
Cornish said demolition crews are expected to have the 415-foot section of the viaduct reduced to crushed concrete and rebar in four days.
Over the next several weeks, Cornish said, the contractor will tear down and haul off more than a quarter-mile of the old viaduct, which first lifted traffic over the Nalley Valley in 1971.
The demolition is the first phase of a $115 million construction project that will streamline traffic connections between eastbound Route 16 and I-5.
The westbound portion of the Nalley Valley project, a $184 million job that overhauled connections for I-5 traffic headed toward the Tacoma Narrows Bridge and Gig Harbor, took 21/2 years and was completed in June.
The eastbound project is expected to take another 21/2 years, winding up in spring 2014.
Some 132,000 vehicles use the Nalley Valley junction each day, so construction must be planned to minimize traffic delays.
Plans call for the now-unused westbound portion of the old viaduct to be demolished first, to make room for construction of a new eastbound structure.
Several months into the project, eastbound traffic will be diverted onto the new structure, Cornish said, clearing the way for demolition of the old eastbound viaduct.
Much of the construction work that will stop traffic, such as lifting big precast girder sections, will occur at night to avoid inconveniencing drivers as much as possible.
Neal Uhlmeyer, the transportation department’s project engineer for the eastbound project, said the contractor will install close to 200 girders during the course of the work, meaning up to 80 nights of road closures and detours.
Also, during eastbound Nalley Valley project construction, two I-5 ramps – Exit 133 on northbound I-5, which takes drivers to Tacoma’s city center, and the southbound I-5 Exit 132 to South 38th Street and the Tacoma Mall – will be closed for as long as three months.
Rob Carson: 253-597-8693 rob.carson@thenewstribune.com
JOIN THE DISCUSSION | Register here
We welcome comments. Please keep them civil, short and to the point. ALL CAPS, spam, obscene, profane, abusive and off topic comments will be deleted. Repeat offenders will be blocked. Thanks for taking part — and abiding by these simple rules. A thorough explanation of rules of conduct can be found in our Terms of Service. If you have any questions, including why your comment may not be showing immediately after you submit it, be sure to visit the commenting FAQ.