The Evergreen Line, located east of Vancouver, links the cities of Burnaby, Port Moody, and Coquitlam with an 11-kilometer-long (6.8 mi) light rapid transit line between Douglas College in Coquitlam and Lougheed Town Centre in Burnaby. The Evergreen Line connects with the Millennium Line in Burnaby and extends to downtown Vancouver, and the Vancouver International Airport via the Canada Line. The transit line includes a 2‑kilometer-long (1.2 mi) bored tunnel.
Delve Underground’s role in the tunnel design included segmental lining design, ground improvement and interface coordination at tunnel portals, geotechnical design services, development of an instrumentation and monitoring plan, and design support during construction.
We also developed the tunnel boring machine (TBM) excavation requirements (which were incorporated into the Plan for Tunnel Advance and included EPB pressures for the alignment), and completed structural design for the TBM thrust frame and gantry crane foundation at the launch portal, and an innovative invert design.
Other project components consisted of elevated and at-grade guideways, seven stations, power substations, train operating systems, parking facilities, and a vehicle storage and light maintenance facility.
Aside from short sections at either end of the tunnel with low ground cover (which was steel bar reinforced), the one-pass segmental lining was designed with steel fiber reinforcement—a first for an area of moderate seismicity. Additionally, the invert design included the use of granular fill to accommodate seismic ground motion and provide drainage of any groundwater leakage through the lining to the low point at the east portal.
Design Build Institute, 2017