Kicking Horse Canyon Phase 4 (KHCP4) is a $600 million Design Build project that includes the design and construction of improvements to 4.8 km of the existing Trans-Canada Highway 1 to provide a four-lane divided standard with a 100 km/h design speed and geohazard mitigation. Challenges included steep terrain, unstable slopes, and an environment subject to rockfall, avalanche, and debris flow hazards. The project achieved Substantial Completion at the end of November 2023 with all lanes available for traffic.

The project provided infrastructure improvements that reduced exposure to geotechnical and environmental hazards for improved safety and reliability along Trans-Canada Highway 1, while also avoiding net impacts to another nationally significant goods movement corridor: the Canadian Pacific Kansas City (CPKC) rail line in the canyon below, which carries 30 trains per day and connects to ports on the Pacific Coast. Rock cuts, excavations, ditching, grading, and bridge clearances for the new highway alignment were applied to strategically protect it against avalanche, rockfall, and debris flows. In addition to reducing the frequency and severity of these disruptions, the improvements also provided a more robust and resilient drainage system, and underground power and communications links to better protect the infrastructure from severe weather and climate change impacts, which have resulted in significant economic and supply chain disruptions in recent years.

Where changes in rock elevation necessitated changes to structural and/or retaining wall arrangements, the KHCC team worked with the client to undertake value engineering proposals which included changing the spacing and configuration of foundations, excavation to reduce loading on unstable slopes, and conversion of wall sections to viaducts.

A combination of short- and selected long-term lane closures, traffic shifts, and detours were implemented to safely complete the project.

Innovative roadway, geotechnical, and structural design and construction techniques were required to deliver this complex project featuring steep and unstable slopes, high rock cuts, and limited space for traffic detours. The highway alignment drove the configuration of bridges, walls and upslope excavations.

Vertical and horizontal geometric options were developed early on and refined as geotechnical information was processed and analyzed. Four bridges and nine viaducts were taken to detailed design and construction on the project, with almost half of the project’s limits consisting of elevated segments. Each was designed to accommodate unique features and hazards with three bridges designed to pass avalanche and debris flows beneath the bottom of girders and allow for large animal passages under the highway. Due to the steep terrain and site conditions, the foundation designs for structures included a variety of foundation types including micro-piles, drilled shafts with permanent steel casings, spread footings on rock with dowels, and tie-back anchors. Access to the site required unique and innovative means and methods for bridge construction. Nearly all the temporary works designs for the project were provided by the in-house construction engineering team. This specialty scope included the crane trestle design, girder assembly tower design, truss analysis, truss supports, launching and jacking details, girder stability and erection sequence, and detailed rigging drawing.

Features to improve safety and reliability included:

• Structures accommodate avalanche pressures, and ditches prevent snow from impacting the highway.
• Rockfall attenuators for the most prone areas of the corridor. • Stabilization of slide areas using excavation, dewatering, and anchoring to reduce slope loading.
• Road safety enhancements including widening to four lanes divided, improved geometrics, and wider shoulders. 
• Fencing to direct wildlife to landscaped passages under bridges.