Neighborhood vibration testing, construction to close SR-520 bridge over upcoming weekend
Aug 25, 2022, 6:21 AM
(Steve Voght via Flickr)
While construction on the Portage Bay connection on State Route 520 between Montlake and I-5 is years away from starting, workers will use this weekend’s closure of the freeway to begin preparations.
SR-520 will be closed in both directions this weekend. Contractors will be working on the lid and making preparations for the next phase of the project, which is finishing the widening of the freeway over to I-5. The Washington Department of Transportation’s Steve Peer said they need all the lanes of the freeway because they are working above them. “We’re placing 24 girders for the Montlake Lid,” he said. “We’re using a lot of this closure to shift the highway a little bit and widen the work zone under the new lid.”
They will be using this full closure to put a crane up in the eastbound lanes to drill a pile shaft into the ground. This pile will be driven into the ground near Boyer Avenue to test a couple of things. Engineers need to test the soil for future construction, and they are testing how driving those future piles will vibrate the nearby neighborhood. “We’ll be able to use those measurements to write the scope for the limits of what future contractors can do in that area,” Peer said.
Contractors used to not care about noise or vibrations when it came to projects, but WSDOT has changed its philosophy over the years. Peer said WSDOT wants to be a good neighbor. It wants to get the work done with little impact to the community. “We want to measure this pile driving to make sure that the future project is a good neighbor when building the trestles.” he said.
And this won’t be the only test pile they complete. Another shaft will be driven in early September. That one will actually be in the water of Portage Bay.
The closure starts at 11 p.m. Friday night and should last through early Monday morning.
This won’t be the only freeway closure to deal with. Revive I-5 is back. Shocker, right?
The state will be closing southbound I-5 between I-90 and the West Seattle Bridge from Friday night through Monday morning. All traffic will be diverted into the collector-distributor lanes. “It could be a double-whammy for drivers,” Peer said.
This is going to make getting to the Mariners a lot more difficult. We’ve got Ichiro Hall of Fame night Saturday and a bobblehead giveaway Sunday.
Be sure to plan extra time to get into and out of the Stadium District.