The Seattle Times » The massive drill has veered a few inches off course.
GeekWire » The Washington State Department of Transportation (WSDOT) takes viewers on a behind the scenes construction tour of the new double-deck State Route 99 tunnel. WSDOT’s Deputy Administrator explains how the tunnel boring machine, known as Bertha, works to dig through the ground and place concrete rings to form the tunnel wall as she goes. Watch […]
GeekWire » Seattle Tunnel Partners (STP) has released a video of construction crews performing routine maintenance on Bertha, the tunnel boring machine, which includes power washing the cutting head and replacing cutting tools that weight 75 pounds each. Bertha is outfitted with 700 cutting tools (or teeth). During this maintenance stop STP has inspected 400 teeth, replacing […]
The Seattle Times » The Alaskan Way Viaduct was scheduled to be closed for two weeks beginning on April 29 so Bertha, the tunnel boring machine, could work under the existing tunnel and move forward 385 feet. The Alaskan Way Viaduct reopened five days earlier than scheduled, but Bertha still needs to finish boring the remaining 73 […]
The Seattle Times » In January 2016, a geotechnical expert for the Washington State Department of Transportation (WSDOT) warned officials of possible over excavation and ground loss one day before a sinkhole appeared 110 feet behind the tunnel boring machine’s cutting face. WSDOT and their consulting engineers are concerned about the contractor’s ability to maintain soil […]
The Seattle Times » The Seattle Tunnel Partners (STP), the contractor on the Highway 99 tunnel project, submitted a report to Washington state officials to explain why a sinkhole formed near Bertha’s (the tunnel boring machine’s) repair site. In a statement, Governor Inslee said the information provided was insufficient.