OHL North America webpage - Home



Toronto York - Spadina Subway Extension

Section: Highway 407 Station and Northern Tunnels

Client: Toronto Transit Commission

Contract Model: Lump Sum

The Toronto - York Spadina Subway Extension (TYSSE) is an 8.6 km extension that will connect the city of Toronto to the regional municipality of York. OHLA was awarded the Highway 407 Station and Northern Tunnels contract to begin construction in early 2011.

Highway 407 Station

The highway 407 station is located south west of the 407 ETR & Jane St intersection. The station will serve as a multi-modal transportation hub providing parking for up to 600 commuters, as well as 30 passenger pickup and drop-off spaces (PPUDO). The new facility also incorporates an 18 bay York Region Transit (YRT) and GO Transit bus terminal. As part of the 600 parking spaces, 14 accessible parking spaces will be provided adjacent to the PPUDO, near the entrance to the TTC facility.

In addition to incorporating barrier-free access elements, the overall design also required provisions for a future connection to the MTO’s proposed Highway 407 transit way. The sloping roof of the bus terminal will be clad with a standing seam roofing system utilizing clear anodized aluminum and will include allowances for landscaped berms where the structure curves down toward ground level. All bus terminal glazing is bird-friendly “fritted” glass fitted within black aluminum curtain wall framing. Cornice and roof overhang soffits are clad in zinc coated aluminum panels to create a seamless, visually appealing sightline transition from ground level to roof.

The subway platform is served by an elevator from the concourse level, four high capacity escalators, and an architectural stair & ramp assembly. There are no columns in the platform area, which creates unobstructed upward and outward views to the skyline from the maintenance level through to the top of the sloped windows and artwork above.

The Northern Tunnels

This is the most challenging and complex section of the entire TYSSE project. It consists of 7,280 m of excavated tunnels created using an earth pressure balance (EPB) tunnel boring machine (EPB-TBM).

The twin tunnels (3,640 m each) were bored at an average depth of 18 m. The project also required 220 m of Sequential Excavation Method (SEM) tunnel and 2 sections of cut & cover tunnel structure: North wye- 100mx20mx20m & South wye -61mx20mx20m.

Compensation grouting will also be required for settlement management beneath 3 buildings.

The work also includes:

  • 4 emergency exit buildings (EEB-4, EEB-5, EEB-6 & EEB-7)
  • 3 cross-passages (CP-5; CP-6; CP-7)
  • Tunnel invert slab, walkway and embedded conduits included in the project scope