Pape SOE

To support the Ontario Line subway expansion at Pape Station, GIP executed specialized geotechnical construction focused on precise ground stabilization and engineered structural reinforcement in preparation for station excavation and tunnel boring. The scope encompassed the installation of deep reinforced concrete slurry walls and a jet grouting program, both designed to enhance subgrade conditions and deliver a watertight, robust support of excavation (SOE) at the critical station-tunnel interface.

Slurry wall construction consisted of installing reinforced concrete diaphragm walls using hydromill trenching equipment paired with a bentonite slurry containment system to stabilize trench faces. The bentonite slurry was generated on site and continuously recirculated to maintain wall integrity until reinforced concrete was placed, thereby establishing a permanent structural and waterproof foundation for the Ontario Line interchange at Pape Station.

GIP also completed a staged jet grouting program along Gertrude Place near Muriel Avenue, injecting high-pressure grout to form engineered soil columns that reinforce the ground and minimize water infiltration before excavation. All work occurred in a densely built urban area, requiring coordinated traffic management, pedestrian safeguards, acoustic barriers, and phased construction.

Working below a dense Toronto neighbourhood, the priority was precision over volume. GIP's slurry wall system used bentonite (a naturally occurring mineral) as a temporary stabilizer during excavation, displacing the need for more invasive shoring methods. Jet grouting created cemented soil columns in place, using what was already there rather than importing structural fill. The result was a tight, contained construction process with minimal surface disruption above