Kicking Horse Canyon Phase II
October 1, 2008
By Canadian Consulting Engineer
The original roadway of the Trans Canada Highway along the Kicking Horse River near Golden, B. C. was a winding, two-lane road. Up to 10,000 vehicles use the highway during peak season, with 24% of th...
The original roadway of the Trans Canada Highway along the Kicking Horse River near Golden, B. C. was a winding, two-lane road. Up to 10,000 vehicles use the highway during peak season, with 24% of the traffic representing heavy trucks. The prime objective of the project was to improve safety on the notoriously dangerous stretch of road.
Upgrading the 5.8-kilometre Phase II section of Highway 1 meant traversing extreme mountainous terrain and presented many engineering and geotechnical challenges. The project changed the alignment to produce a new road with a 100-km/hour design speed, reduced grades, and extended shoulders.
Besides making the road safer, the project removes the traffic flow from the banks of the Kicking Horse River to an elevated position, allowing the banks to recover and be replanted. The environmental challenges of the project as a whole were significant, requiring a review under the Canadian Environmental Assessment Act.
The project was done as a public-private-partnership (P3) between the Trans Park Highway Group (TPHG) and the B. C. Ministry of Transportation. On behalf of the TPHG Group, Golder was involved in key geotechnical and environmental issues, while Parsons and Delcan were responsible for the bridge design and construction supervision and management.
Geotechnical and structural challenges
The terrain presented significant geotechnical constraints. The Rocky Mountains have undergone major tectonic deformation, periods of glaciation, and subsequent rapid valley incisions. Variable depths of glacial till are plastered on top of highly undulating, steeply inclined, poor quality bedrock, including limestone, shale and quartzite.
The selected alignment for the new road reduced the highway gradient to less than 6% and required the construction of the new Park Bridge. The bridge has a total span of 405 metres and features five piers up to 90 metres high above the canyon base. They are the highest piers of any steel girder bridge in B. C.
The major engineering challenges related to the bridge included the design and construction of (1) 90-m high rock cuts through these varying, very poor quality rock types for the approach to the bridge, and (2) engineering the foundations for the bridge’s piers. The project also required the largest application in Canada of high-tensile mesh to retain material within near-vertical slopes up to 14 metres high.
Advanced analysis methods were used to develop geological and geomechanical models to provide a three-dimensional understanding of potential foundation failures.
The bridge foundations typically required up to 16 piles per pier, 900 mm in diameter. Some of those piles had to be bored and steel cased for up to 45 metres through overburden before being socketed 8 metres into the bedrock.
Park Bridge also represents the first North American application of an incrementally launched curved girder bridge. Using this approach significantly reduced the construction time and cost. The girders were manufactured at both ends of the country –in B. C. and Quebec –assembled off site, and then launched using hydraulic jacks that pushed them at a rate of 20 metres per hour across the spans between the abutments and piers. The front end of the section included a removable nose section to ensure that launched girders would land smoothly on each pier. This process was used for the entire 405-m span.
The Phase 2 project was completed 21 months ahead of schedule and opened in August 2007 for a total cost of $143 million, saving $18 million from the original estimate.
Project name: Kicking Horse Canyon -Phase II, Golden, B. C.
Award-winning firms and roles: Golder Associates, Squamish & Victoria, B. C., geotechnical and environmental subconsultants (Rich Humphries, P. Eng., Paul Schlotfeldt, P. Eng., Don Lister, P. Eng., Dave Munday.
Delcan Corporation, Vancouver & Calgary, bridge and wall design subconsultant (Joost Meyboom, P. Eng., Hugh Hawk, P. Eng.)
Owner: B. C. Ministry of Transportation
Client: Trans-Park Highway Group (TPHG) joint venture
Joint venture partner, design management, bridge design: Parsons Transportation Group
Roadway design subconsultant: Stantec Consulting
Other key players: Flatiron Constructors Canada (TPHG joint venture leader and construction management); Bilfinger Berger BOT (TPHG concessionaire)