Two tunnels that will help increase capacity on GO Rail’s Kitchener Corridor have reached substantial completion, a milestone Metrolinx says marks the end of heavy construction, with only finishing touches and repair of minor deficiencies left to be completed.
Construction to excavate the tunnels began in July 2019, with completion of the first tunnel excavation achieved in August of 2020 followed in February 2021 with completion of the second tunnel excavation.
The excavation description is enough to get any engineering professional’s heart beating, but Metrolinx says the real “engineering bit of urban magic” is that the work took place less than three meters (9.8 feet) beneath 21 active lanes of Highways 401 and 409 without disruption to traffic.
“The project is a significant achievement and provides key infrastructure for the Kitchener line,” said Franca Costantino, Metrolinx senior manager of the project delivery team. “The tunnels will eventually help get more commuters off the roads and onto public transit, improving quality of life for many people.”
As crews worked to excavate the tunnels, shotcrete was applied, followed by installation of the final liner, which smooths the tunnels for track installation to take place. Metrolinx says the final lining work took place in May 2021.
In 2017, Toronto Tunnel Partners (TTP) was awarded a C$116.9 million (US$91.88 million) contract by Metrolinx and Infrastructure Ontario to build the two tunnels. TTP is working with Metrolinx to perform finishing touches and correct any minor deficiencies, such as final smoothing of the concrete of the tunnels or retaining walls.
The next steps for construction of the tunnels include track installation, signaling and communications infrastructure, which will be performed under a separate contract.