WSDOT insists no threat of Alaskan Way Viaduct closure from Bertha tunneling
Feb 25, 2014, 1:23 PM | Updated: 1:52 pm
Despite media reports to the contrary, the Washington State Department of Transportation insists Bertha’s tunneling below Seattle is not threatening the Alaskan Way Viaduct.
The viaduct has settled 4/10ths of an inch because of the tunneling, prompting City Councilman Mike O’Brien to speculate Monday the viaduct could be shut down and the city should start making contingency plans.
But Todd Trepanier, administrator of the Alaskan Way Viaduct replacement project, said the settlement was expected. And he said, during a conference call with media Tuesday, crews are constantly monitoring the viaduct and can reinforce it if needed.
“This was settlement that was anticipated and known it would happen because of the tunneling activities. And Seattle Tunnel Partners, as part of the contract, designed for that and strengthened the viaduct to be able to deal with those settlements,” Trepanier said.
The viaduct has been settling for years in varying amounts along the entire stretch of the elevated roadway. It remains vulnerable to earthquakes, and WSDOT has an emergency closure procedure in place in case of a catastrophic event. But short of that, there’s nothing to indicate the viaduct faces any undue threats from the tunnel project, Trepanier said.
“If there was any indication that something had to be taken care of, that would be noticed and something would be done before there was any issue of having to close the viaduct.”
Over 100 monitors have been installed along the viaduct to measure settlement, according to WSDOT. While the agency constantly monitors near the tunneling activity, WSDOT also closes the viaduct twice a year to inspect the entire roadway. One of those closures happens this coming weekend and was previously scheduled, Trepanier said.
Bertha the tunnel machine has been stalled since early December because of a mechanical problem. WSDOT expects to determine later this week how long repairs will take and when tunneling might resume.
