Alaskan Way Viaduct
A new highway tunnel through downtown Seattle won’t be open until August 2017, about 20 months behind schedule, state transportation officials said Monday.
Settling soil has caused a contractor building the Highway 99 tunnel beneath downtown Seattle to stop work on a pit being dug to reach a stalled digging machine known as Bertha, the state said.
Bertha, the broken-down tunneling machine, moved forward three feet during recent testing, while workers building an underground circular pit that will allow access to the machine finished installing the last of 84 large concrete cylinders known as piles.
Bertha, the machine boring the State Route 99 tunnel in Seattle, will not resume digging until the end of March 2015 and that the tunnel will not open until November 2016, according to the Washington State Department of Transportation.
It seems that everything connected with the effort to dig a highway tunnel under downtown Seattle is big — from the tunneling machine that stopped working last December, to a large plywood wall planned to shield neighbors from the noise of repairing the machine.
A routine inspection was conducted the weekend of March 1-2 and discovered new and widening cracks near Spring and Seneca streets.
An official for the contractor boring the Seattle Highway 99 tunnel says a six month delay in the stalled construction is a “slightly optimistic” forecast.
The Alaskan Way Viaduct has sunk nearly half-an-inch at one location where a machine has been boring a highway tunnel under downtown Seattle.
Wash. DOT says many of Big Bertha’s cutter-head openings are clogged with dirt and debris.
Seattle’s massive tunneling operation is on hold yet again due to ongoing problems with the world’s largest boring machine, officials said Friday.