Wednesday, January 21, 2015

How we build things in Seattle


 The Bertha "rescue" pit

Some local wags have commented that the rescue pit looks like a giant toilet. You know, the kind you throw money down?

The elevated Alaska Way viaduct has sunk more than an inch near the tunnel machine's rescue pit, and at least 20 buildings in Pioneer Square are sinking.  The state has reportedly said that the viaduct could sink another six inches total.  Now the city of Seattle has hired its own engineering consultants ($150,000) to take an independent look at the dangerous 1958 Alaskan Way Viaduct, to see whether groundwater removal and other Highway 99 tunnel work poses a "hazard."  Hazard is a much nicer word than catastrophic failure.

The tunnel digging (the most difficult part of the project) is only about one-tenth finished. They've dug 1,000 feet and have roughly 1.5 miles to go. The tunnel boring machine has been broken for over a year (they don't know why) and has to be hauled out of the pit with a crane for repair. It weighs 4 million pounds.  Costs are rising, but there's no plan to pay for cost overruns. The project is more than a year behind schedule, and officials at the highway department can't commit to a timeline for finishing the tunnel (if ever) or tearing down the viaduct.

How much more can the ground settle before they shut down the viaduct?  No one knows. And at this point, there's no plan for how 100,000 vehicles a day will be diverted onto already clogged downtown streets.

Reporting from Seattle, over and out...

No comments:

Post a Comment