Dive Brief:
- Tunnel boring progress on the $3.1 billion Alaskan Way Viaduct project in Seattle has reduced projected cost overruns from $223 million to $149 million, according to The Seattle Times.
- Bertha, the tunnel boring machine, has managed to operate consistently for the last several months and is 72% complete with the $2.1 billion, 2-mile path that will carry State Route 99 under downtown Seattle.
- Joe Hedges, program administrator for the Washington State Department of Transportation (WSDOT) told The Seattle Times that an additional $69 million could be whittled away if there are no further delay-causing problems.
Dive Insight:
However, that $149 million could skyrocket, according to The Times, if the state is forced to pay an extra $480 million to Seattle Tunnel Partners for Bertha-related charges. The construction team claimed that the WSDOT did not inform it of an 8-inch steel pipe in Bertha's path, which resulted in damage that took approximately two years to fix. The WSDOT has consistently disputed that claim.
In November, a superior court judge in Thurston County, WA, ruled that STP was not able to collect on damages to Bertha under the design-build contract it signed, as it prevents reimbursement for damages to equipment.
After Bertha was repaired, it restarted tunneling operations in December 2015, but about a month later, WSDOT and Washington Gov. Jay Inslee stopped work again after a sinkhole opened up over the tunnel boring machine.
STP filled the sinkhole with concrete and reported back to WSDOT that the sinkhole came about because of "a pre-existing void, a ground loss in the face of the (tunnel-boring machine), or a combination of both." WSDOT and the governor "conditionally lifted" the stop-work order in February. STP subsequently furnished the state with a soil monitoring and removal plan.