Officials at the Washington State Department of Transportaton (WsDOT) announced this week that the Alaskan Way Viaduct, which was expected to see completion in calendar 2015, will now not open to traffic until mid-2017.
A memo issued by WsDOT indicated that the new completion date would be “later than the November 2016 date [the contractors, Seattle Tunnel Partners] had been targeting” since the work stoppage that was the result of a broken-down boring machine.
As previously reported by Roads & Bridges, the tunnel boring machine known commonly as Bertha has been waylaid since December 2013 due to a damaged 57-ft diameter cutting head. In order to reach the machin in order to make repairs, crews had to make an 80-ft diameter access pit to a depth of 120 ft. Soil settlement in the area, as well as concerns over the structural integrity of adjacent buildings, further disrupted rescue operations, and now it seems that STP and WsDOT are having to hit the reset button on what could be called realistic expectations.
WsDOT believes tunneling will resume in April 2015, now that the settlement issues have stabilized to scientists’ satisfaction. “We have conducted 50 building surveys since Dec. 7 and our survey efforts are ongoing,” the DOT said via memorandum. ”Survey crews have found some minor cosmetic damage in a handful of buildings, but no structural damage has been discovered. While Seattle Tunnel Partners provides us with a schedule each month, we cannot endorse a project completion date until the work is further along. While we are confident the project will be completed, a schedule we can endorse will likely come into greater focus only after the access pit is complete and the tunneling machine has demonstrated it can successfully mine. This is very difficult work, and certain construction activities have and will continue to take longer than anticipated.”
The present viaduct has been considered unsafe since the Ash Wednesday earthquake of 2001, which caused the nearly 70-year-old waterfront freeway to sink. Ex-DOT Secretary Doug MacDonald has acknowledged in statements to the press that the structure might well have toppled altogether had the quake continued for a further minute, possibly less.
