Scarborough Subway Extension

SENER Canada
Toronto, Canada
2024-2025

The Scarborough Subway Extension project is a major transit infrastructure initiative to extend Toronto’s TTC Line 2 subway by 7.8 kilometers, connecting Kennedy Station to McCowan Road and Sheppard Avenue. The extension includes the construction of three new underground stations as well as improved connections to other transit systems like the Eglinton Crosstown LRT, GO Transit, and Durham Region Transit. The project design life criteria ranged from 50 years to 100 years.

Performance-based approach to design and selection of material

SIMCO was hired as durability consultant to design and optimize the concrete mixtures and establish material specifications to ensure the achievement of service life for the main underground structures and secondary structures. The proposed approach required mitigation strategies for the impact of stray current on the reinforced concrete and steel elements. Our scope of work included:

• Analysis of the environmental and operational loads to identify potential degradation mechanisms
• Evaluation of the impact of stray current on material durability for corrosion control
• Elaboration of provisions and avoidance strategies for the identified degradation mechanism and stray current
• Service-life STADIUM® calculations for reinforced concrete elements (fib Bulletin 34, ISO 16294 and ACI 365.1R-17 compliant)
• Establish critical limits and performance thresholds for concrete and steel elements to meet service life
• Evaluation of waterproofing and protection systems
• Recommendations for material and construction method
• Evaluation of thermal control plan 
• QA/QC guidelines for construction

SIMCO’s approach relied on quantitative predictions of the structure’s durability, incorporating specific exposure conditions and locally sourced materials into performance calculations. This approach ensured that all considerations aligned with the material property requirements to fully comply with the project specifications established at the design phase.

For more details about the project :

Sener Chosen as Lead Designer for the Extension of Toronto Subway Line 2

Scarborough Subway Extension

Image credit: Metrolinx