WATCH: TBM breaks through in Seattle
The tunnel boring machine (TBM) on the Alaskan Way Viaduct replacement tunnel has broken through, after tunnelling for more 2.8 km underneath Seattle, Washington.
The TBM, affectionately known as Bertha, laid a total of 1,417 concrete rings along the route which will form the walls of the new tunnel.
Governor of Washington Jay Inslee said “This is a historic moment in our state’s transportation history.
“Innovation and perseverance are the engines that keep Washington at the forefront. There is still more work ahead but this moment is one worth celebrating.”
The construction team will now spend several days removing steel support braces between Bertha and the inside of the 27.5 m disassembly pit where it broke through.
Once the braces have been removed, the machine will be driven to its final position where it will be cut into pieces for removal.
Seattle Tunnel Partners Project Manager Chris Dixon said “We were always confident that we would successfully complete the tunnel drive.
“The dedication and commitment of everyone on the Seattle Tunnel Partners team has been exceptional, and we wouldn’t be at this milestone without the hard work of our crews.
“We look forward to continuing this outstanding progress through project completion.”
The four-lane toll tunnel was set to open by the start of 2016 to replace the earthquake damaged Alaskan Way Viaduct, as part of the US$3.1 billion Viaduct replacement.
However, a series of issues plagued the project including the TBM drawing to a halt, leading the JV to make significant insurance claims against the project’s owner, the Washington State Department of Transport.
For more information visit the Washington State Department of Transportation website.
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Images supplied by the Washington State Department of Transportation.