According to the STM, the principal contractor and project manager of the Montreal Metro Blue line extension, a pre-qualification notice was launched on April 19th for the construction of the tunnel of the blue line metro extension.
The use of a tunnel boring machine (TBM) is planned for most of the excavation work. “This will be the first use of a TBM in the long history of the STM,” says Marie-Claude Léonard, Interim CEO of the STM."
“It will allow us to speed up the excavation process and will help us to build high-quality infrastructure as we extend the Blue line of the Montréal métro.”
Multiple advantages
The TBM method of tunnel excavation and construction is faster than traditional methods, which will help to keep the project on schedule. Perfect for a rocky subsurface such as the blue line extension, the TBM also has the advantage of being less disruptive to neighborhoods on the surface, as it causes less noise and vibration.
The specialized machine will also provide lasting results and more waterproof tunnel walls, due to the use of pre-made concrete rings that will be installed along the way as the TBM bores through the ground. From an environmental perspective, the TBM has the added advantage of operating on electrical power, thus less polluting.
The TBM used for the blue line extension excavation work should be able to move at an estimated rate of 13 to 15 meters a day, on average.
