Ottawa Light Rail

Owner
City of Ottawa
Client
Dragados - SNC Lavalin - Ellis Don
Cost
$3 billion CAD
Timeframe
March 2012 — ongoing
Services performed
Tender design, preliminary and full detailed design including execution drawings for three mined station caverns, adits and shafts. Additionally, construction support services on site were provided.
Description
The confederation Line in Ottawa encompasses 15 stations and stops; its centre piece is a 2.5km long tunnel with three underground stations underneath downtown Ottawa. The mined construction method for the stations was chosen in order to minimize the impacts to the surface. The underground stations are located directly adjacent to existing, sensitive and sometimes historic buildings requiring detailed studies of risks during construction and risk mitigation measures.
Geology
The geology varies from strong limestone to competent and fractured shale. A soft ground section includes highly disturbed glacial sand/silt/clay deposits with a high water table.
Location
Ottawa, Canada

Highlights

  • 3 large caverns and Twin Track Running Tunnel in rock
  • Sensitive urban environment in close proximity to existing infrastructure
  • Minimum surface impact during construction
Cavern construction under way

Cavern construction under way

Downtown stations located between high-rise buildings

Downtown stations located between high-rise buildings

Mined Caverns directly adjacent to existing basements

Mined Caverns directly adjacent to existing basements

Special Excavation Sequences incorporating pre-tensioning

Special Excavation Sequences incorporating pre-tensioning

Large-Scale 3D Numerical Modelling incorporating the surroundings

Large-Scale 3D Numerical Modelling incorporating the surroundings