By Ashley Karen
Metro Vancouver is building a new $286 million water supply tunnel in-depth beneath Burrard Inlet, east of the Ironworkers Memorial Bridge between the City of Burnaby and the District of North Vancouver.
The Second Narrows Water Supply Tunnel Project – Burrard Inlet Crossing contains a 1.1-km tunnel, two shafts and near-surface structures (valve chambers). It is one of five new regional water supply tunnels being developed to meet existing seismic standards to guarantee the reliable delivery of drinking water in the region in the event of a significant earthquake.
Moreover, once completed, the tunnel will enhance the current system’s capacity to meet the long-term requirements of the growing population.
The project team employed a 7-bar pressure slurry (Mixshield) tunnel boring machine – a first for a metro-sized tunnel in Canada. As reported, tunnel excavation, pipe installation and backfill are complete. Also, shaft pipe installation and near-surface valve chamber construction are underway.
The new water supply tunnel will be bored in-depth underground utilizing a TBM. The tunnel boring machine will launch from a vertical entry shaft on the North Vancouver side and headway south beneath Burrard Inlet to the vertical exit shaft on the Burnaby side. When the tunnel is bored, three steel water mains will be installed inside the new tunnel and linked to the new valve chambers at each shaft site and into the region’s drinking water system.
Project team: Traylor Aecon General Partnership: Contractor; Metro Vancouver: Owner; Delve Underground: Tunnel and Shafts Designer; AECOM: Near Surface Works Designer; Mott MacDonald: Construction Manager; Herrenknecht: TBM Manufacturer; Southwest Contracting: Earthworks Subcontractor; Jewel Holdings: Pipe Welding and Coating Subcontractor; Aecon Water: Large Bore Mechanical Installation Subcontractor; Black & McDonald: Electrical, Instrumentation, HVAC, and Fuel Oil Subcontractor; Nucor-Harris Rebar: Reinforcing Steel Subcontractor.
Personnel: Construction Manager: Patrick Hamlin (Mott McDonald); Engineer of Record: Andrew McGlenn (Delve); Owner’s Representative: Mark Qian (Metro Vancouver); Project Manager: Erica Frederickson (Traylor); Project Engineer: Brian McInnes (Aecon); General Superintendent: Ty Winters (Traylor).
