In 2016, Parks Canada commissioned a new wildlife overpass over the Trans-Canada Highway through Yoho National Park. Our client, Eagle Builders LP, retained CVL Engineers Inc. to provide structural design for the overpass.
Unlike other overpasses along the highway, there were topography limitations here that made a double arch over individual lanes of traffic impossible. Instead, the single precast concrete arch would need to be designed with a length of 58m and a clear span of 33.4m, making it one of the largest concrete arches in the world, and the longest animal overpass in the world.
With this lofty goal ahead of us, the CVL Engineering team got to work on designing the structure. The arch was designed to be constructed with precast concrete segments, with a cast-in-place concrete key at the peak of the arch.
We accommodated for the effects of heavy snowfall, drifting, and winds in the area, as well as the impact of backfill on top of the structure (which created a seamless transition for wildlife to pass over). Loading information provided by Parks Canada was used to determine the loading requirements for the overpass.
The design was completed to the Canadian Highway Bridge Design Code, along with Parks Canada specifications requirements. The engineering and detailed design costs represented a very tiny fraction of the overall construction costs for this project. Some portions of this mega-engineering project were built over live traffic during peak season in Yoho National park, as shown in this video feature on Discovery Channel.
Despite the challenges and colossal size of the structure, construction went ahead exactly as planned with no major hiccups.