This is an interesting video of crews changing cutterhead teeth on the Bertha TBM beneath downtown Seattle. [Source: WSDOT YouTube Channel. Image: YouTube]
Video: Changing cutting tools on Bertha TBM
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Seattle tunnel will go under 158 buildings
The tunnel replacing the Alaskan Way Viaduct (SR-99) will pass beneath 158 existing structures requiring an extensive program of vibration and settlement monitoring as well as some remediation. Of the 158 buildings, WSDOT identified 20 […]
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Feb. 7 Bertha update: Two factors contributed to tunnel stoppage
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]
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Conceptual Plan for Excavation to Repair Bertha TBM
Seattle Tunnel Partners has released a conceptual plan showing what the excavation of the pit will look like to repair the damaged Bertha Tunnel Boring Machine. See below. A pit 120 feet deep and 83 […]