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]
Current projections put the project completion 35-months behind schedule because of problems with a portion of the TBM constructed tunnel. The County is suing for $74M in damages associated with the delays. This massive sewer […]
These are some really fantastic photos of the Devil’s Slide tunnel construction. For those who aren’t familiar, the tunnels will be bypassing a particularly landslide and rockslide-prone portion of the California Coast that is currently […]