SEATTLE – As we end the first week of the viaduct closure, it looks like Bertha is moving ahead of schedule.
The tunnel boring machine has dug 214 of the 385 feet needed before the viaduct can reopen. Halfway through an estimated two week closure, Bertha is about 55 percent done.
Bertha is starting to emerge out from underneath the viaduct at Yesler and Alaskan Ways. If the machine’s pace continues, there may only be one more week in the closure.
WSDOT officials have seen some tiny movement in the dirt underneath the viaduct, from 1/16 to 1/8 inches. This happens because of pressure and thrust that’s put onto the machine’s cutting head. However, officials said it isn’t a concern until they see ½ inch of movement.