Eglinton Crosstown: Over and under the existing subway

By Shawna Munn, P.Eng., Isherwood Geostructural Engineers, and Sarah Speir, P.Eng., Crosslinx Transit Solutions

This article was originally published in DFI’s bi-monthly member magazine, Deep Foundations, January/February 2023 issue. DFI is an international technical association of firms and individuals in the deep foundations and related industries. To join DFI and receive the magazine, go to www.dfi.org.

Cedarvale Station is one of 25 new Eglinton Crosstown light rail transit (ECLRT) stations along Eglinton Avenue in Toronto. It is an interchange station with the existing Toronto Transit Commission (TTC) University subway line and is located at the intersection of two major thoroughfares. The new LRT tunnels run below the existing Yonge Spadina subway line and required total excavation depths of 20 metres (65 feet) to facilitate construction of the new station.

TBM exit and launch shafts

The TTC would not allow the tunnel boring machines (TBMs) to tunnel