Collaboration was the guiding principle for the four ACEC-BC member geotechnical firms that worked side-by-side to help safely design and construct one of Canada’s largest pipeline projects, the Trans Mountain Expansion Project (TMEP). Due to the scale and complexity of the project, TMEP engaged BGC Engineering, Stantec, Thurber Engineering, and WSP (formerly Wood) to provide geotechnical design support to the owner and on-site support to multiple prime construction contractors. Their partnership, facilitated by TMEP, across all project elements resulted in greater efficiency and innovation. The TMEP twins the original 1,150-kilometre Trans Mountain pipeline constructed in 1953 with a modern, larger pipeline. Both pipelines transport refined oil products such as gasoline, heavier oil, and diluted bitumen from the Oil Sands region in Northern Alberta to the Lower Mainland in B.C. At the pipelines’ terminus, refined products supply local gas stations and the remaining products are loaded into tankers for transport to foreign markets. Completed at the end of 2023, at an estimated final cost of $30.9 billion, the construction of one of Canada’s largest infrastructure projects ensures the country remains competitive in the global oil market in a safe and reliable manner. Crossing through both the Rocky and Coastal Mountains and into the Lower Fraser Valley, the new pipeline navigates numerous geohazards including landslides and debris flows, snow avalanche paths and rockfall sites, and a seismically active region. The pipeline also crosses several major rivers, interacts with environmentally and traditionally significant areas, and travels through dense municipalities and congested transportation and utility corridors. Geotechnical Engineering was a key element by providing input into the final route to avoid geohazards where practical, and in the development of mitigation designs where unavoidable. The result is the safe design, construction, and operation of the TMEP.

The vast geography of the TMEP route meant a high number of geohazard sites and varied, challenging terrain. A willingness among all four geotechnical firms to replace competition with collaboration was integral in providing geotechnical support for the technically complex project. Through an informal agreement between senior members of each geotechnical consultant, it was agreed that each company’s staff could be called upon by others when available. This staff sharing included:

• Allowing junior members from one company to consult with senior members of another in the field, providing quicker turnaround on decisions and greater mentoring opportunities.
• For specialty teams that may not be present or available in each firm (such as geochemistry, hydrotechnical engineering, rockfall or seismic modelling), encouraging relevant work to be given to the appropriate specialist regardless of employer. This avoided time and expense in subcontracting the specialty skills.
• When capacity was challenged with multiple sites being constructed simultaneously, drawing upon each other’s staff and equipment to provide coverage without having to search for new staff.

Templates, typical drawings, and ways to approach a challenge were shared amongst the four consultants allowing for optimized and consistent solutions and improved innovation.

Working together through steep and complex terrain, BGC Engineering, Thurber Engineering, Stantec, and WSP, with over 100 fulltime equivalent engineers, collectively completed the design and installation of kilometres of rockfall protection structures, multiple tunnels, more than 300 trenchless crossings, and the design of numerous sections of pipeline with mitigation structures to reduce the risks from landslides, debris flows, and rivers, all while accounting for the effects of climate change.