Seattle’s Alaskan Way Viaduct and Seawall Replacement Project is a political lightning rod, but this amazing simulation video released by WSDOT underscores what COULD happen if a significant earthquake struck the Seattle Downtown Waterfront area.
Seattle’s Alaskan Way Viaduct and Seawall Replacement Project is a political lightning rod, but this amazing simulation video released by WSDOT underscores what COULD happen if a significant earthquake struck the Seattle Downtown Waterfront area.
Construction has started on the tunnel boring machine launch pit for the WSDOT SR 99 Tunnel Project (Viaduct Replacement). The 420 foot long pit is being constructed using secant pile retaining walls, with 2 rows […]

WSDOT released an update on February 7 with some conclusions regarding the blockage that has stopped the Alaska Way Viaduct Tunnel Boring Machine, Bertha’s progress since December 6. Now they don’t think it was necessarily the well casing after all.
They cite two factors that contributed to the blockage. First, the cutterhead was clogged with material. You can see an cool short video of a worker unclogging the cutterhead. Not terribly dramatic, but still cool. The second factor was increased temperatures inside the equipment. STP discovered damage to a seal that protects the machine’s main bearing. They are still determining how the repairs will be done.
If you want to follow the chronology of this issue, read below for summaries and links to previous updates from WSDOT. And Check out the videos too! [Source: WSDOT]
The repaired cutterhead has been in the pit several weeks now, and the final three pieces of shielding for the Bertha TBM have been lowered into the access pit. Seattle Tunnel Partners team members will […]
Copyright © 2007-2020 by Randy Post
