Opening of a new pedestrian tunnel linking the island-based Billy Bishop Toronto City Airport to the mainland for the first time has been celebrated with release of images of the construction phase on Canada’s first drift tunnel project.
Arup was the lead engineer for the 185m long tunnel that takes passengers 35m below the bed of Lake Ontario to access the airport, rather than using the ferry that has served the airport since it opened in 1939.
According to Arup, the driving the 1.85m diameter tunnel through the shale bedrock was highly challenging.
The tunnel was bored using two tunnel boring machines to excavate seven interlocking tunnel drifts that were backfilled with concrete to strengthen ground above the tunnel crown before the core of the tunnel was excavated below. According to airport owner Ports Toronto, this was the first time this technique has been used in Canada.
Instead of taking the ferry, passengers will now access the tunnel via a bank of lifts and travel the length of the tunnel by travelator before emerging into the terminal by escalator.