State highway engineers will shut down a stretch of the Alaskan Way viaduct later this month to take a closer look at cracks found on the roadway.
What workers found during a routine inspection of the viaduct on March 1 isn’t that unusual, says Tom Baker, an engineer with the Washington state Department of Transportation.
“We have seen cracks before, but we haven’t seen them at this location or in this number. So that’s why we want to take a closer look,” said Baker.
The cracks are in the pillars and girders that hold up the viaduct near Seneca Street. They’re small, and impossible to see from street level or while driving. Baker pulled out a piece of fishing line to demonstrate.
“That’s the width of about the widest crack. You can imagine up on the viaduct, it’d be very tough to see,” he said.
The viaduct will be closed for the better part of the day on Saturday, March 22. The inspection will focus on the area around Seneca Street. WSDOT spokesman Travis Phelps says the work will begin with the ivy that grows up the side of the 60-year-old structure.
“We’re going to take that off. We’re going to look at how the crack is responding to heavier load, like a dump truck. We’re going to drive over there and see how the bridge reacts. And we’re going to put some instrumentation on the viaduct because we just want to know, ‘Hey, is this something to be concerned about or not?’” said Phelps.
One thing they know for sure: It’s not a result of the tunnel work. The tunneling machine, Bertha, is about a half-mile away from the trouble spot. The plan now is to fill the cracks with epoxy, which will cost a few thousand dollars. The bottom line, WSDOT says, is that the viaduct is safe for traffic.
