Highway 401 Crossing - Design

Metrolinx and Infrastructure Ontario
Toronto Tunnel Partners - EllisDon & Strabag Joint Venture
$117 million CAD
January 2018 — October 2019
Services performed
Tender support for design during RFP followed by detailed design of excavation and support sequence drawings, primary and permanent lining, sheet membrane waterproofing system including cross passages. Portal wall design. 
TTP delivered two new single-track rail tunnels of approx. 188m length and 11m height each crossing the Highway 401/409 intersection. The aim is to increase capacity along the Kitchener GO commuter rail corridor and to accommodate the new Union-Pearson (UP) Express service. The tunnels are mined less than 5m under the 401/409 Highway using the Sequential Excavation Method (SEM). Tunnel design services were provided to address the challenging conditions (large tunnel cross sections, very low overburden, man-made ground, intercepting piles and other man-made obstructions).
Granular non-cohesive and cohesive embankment fill underlain by glacial till, sands and clay. Subsurface obstructions such as piles, foundations, retaining walls of old Highway construction phases and boulders.
Toronto, Canada


  • Challenging ground conditions, strict settlement criteria enforced by highway agency
  • Adjacent to a live rail corridor in a two track rail tunnel
  • Maximum Overburden of 3-5m in soft ground using heavy pre-support pipes

3D CAD rendering of new and existing tunnel, intermediate shaft and known obstructions.

3D FE-model in Abaqus of new and existing tunnels, and intermediate shaft.