The Illecillewaet Value Engineering project is located along Highway 1 approximately 45 km east of Revelstoke. Emil Anderson Construction (EAC) won the contract for this four-laning project, with the tender design consisting of a shear pile-supported MSE wall, and significant upslope shotcrete walls. The project is located above CP Rail ROW, and a portion of the project crosses over a potentially unstable slope, requiring the shear pile wall. As EAC’s winning bid was much more than the original project budget, both the Ministry and EAC were very interested in exploring the value engineering opportunity for the project. The engineering and construction of value engineering aspects of the project had to be completed within the tender project construction schedule.

BASIS worked with EAC to determine the driving factors of the construction costs. BASIS employed an innovative approach to provide a more cost-effective design solution. By raising the profile of the new highway, the upslope shotcrete and anchor retaining walls were drastically reduced, which in turn reduced the construction cost and overall project schedule.
The eastbound lanes are supported by a 4-span, 136 m long cantilever structure providing an alternate method to support the roadway. The cantilever structure uses a single steel I-girder, with partial depth precast concrete panels to maximize offsite work for the remote site. Uncased cast-in-place drilled shafts instead of steel pipe piles were used to reduce costs, an unconventional approach on transportation projects in BC. The stabilization piles were shifted back from the top of slope to beneath the highway median to reduce foundation costs. Additional geotechnical and structural analyses during the Value Engineering design optimized loading in the foundation elements. MSE walls support the highway off both ends of the cantilever structure. Significant Value Engineering redesigns to the drainage systems were also completed across the project.

The project is located in a critical location along the Trans-Canada Highway between Kamloops and Calgary, with extremely limited options for alternate routes , so being able to keep traffic moving was a fundamental goal for the project. The innovative cantilevered structure designed for the project considered the available space on both the upslope and downslope sides of the existing highway and ensured that maintaining one lane of traffic in both directions at all times during construction was achieved.
Schedule was another critical component of the value engineering design.

The design enabled the major structural components to be prefabricated and then transported to the remote project site. BASIS maintained close coordination with EAC and its subcontractors throughout the course of the project, to ensure that any critical path design items were addressed in a timely fashion. The close coordination with the contractor also resulted in cost savings, as potentially costly structural details were discussed early in the design development, and the contractor was able to provide input into developing more economical options. Using a cantilever system with uncased drilled shaft piles was a unique structural approach by BASIS that was ideal for this location. Overall, this resulted in a structural design that was able to be constructed in a reasonably short timeline, that included significant economic benefits over conventional design approaches.

This project offered BASIS and EAC an opportunity to develop a cohesive and efficient design for the project owner. The project team closely collaborated throughout from concept through to construction, resulting in numerous cost saving decisions and unique simple constructable concepts.

The team achieved over $2 million in cost savings, a reduction of construction risks, completion within the original schedule, minimized environmental footprint, and improved safety for the travelling public.