The Washington State Department of Transportation (WSDOT) recently began construction on a 1.7-mile tunnel for Highway 99 near Seattle's Pioneer Square, and the public is invited to learn more about the project on location. According to SeattlePI.com, WSDOT invited local residents to take a tour of the project, with approximately 200 people showing up on Thursday to find out more about this extensive construction site.
While tunnel excavations have not yet begun, the site is already a hotbed of construction equipment, as cranes, excavators, drill rigs and other machines have already begun working. But there is still plenty to do to prepare for the actual digging of the tunnel, which will replace the Alaskan Way Viaduct that runs through this location. The construction workers will assemble a launch pit that is 80 feet wide and 80 feet deep, in which a tunneling machine will be assembled.
"We're sitting on an alluvial fill...This used to be water under here," Chris Banbridge, a tunnel consultant on the project, explained to tour guests about the loose ground material at the dig site, according to the news source. "The natural ground is some 40 to 50 feet below us. So, in this location, we have to protect the viaduct while we're doing the excavating, and we're doing that by putting in rows of concrete piles."
The preparations will not take place overnight, and Capitol Hill Seattle (CHS) reports that construction crews are not going to begin tunneling until next year. This gives anyone who wants to learn more about the project plenty of time to take a self-guided tour of the site.
There is a pedestrian path that runs alongside the construction zone with informational displays placed strategically throughout. These signs display information about the project, the history of the location, the equipment being used and the different construction activities taking place, according to CHS. There is even a scale model of the tunneling machine on display at Milepost 31, the project's information center located in Pioneer Square. The machine itself will be 300-feet long, nearly 60 feet tall and weigh about 6,700 tons. The $80 million tool is currently being built in Japan, and will be shipped to Seattle in 41 pieces, SeattlePI.com reports.
Local traffic will definitely be affected by this construction work, but WSDOT officials hope the tunnel will be opened to the public by the end of 2015. The project has a $2 billion budget, $1.35 billion of which will go toward design and building contracts.
