Nobody wants to drive off a cliff, or drive past an unstable one, either. The Highway 63 job went through the downtown area, over the Athabasca River and between the Athabasca River Valley and its shaky cliff. Staged construction, overlapping contracts and almost 2 kilometers of tangent pile, secant pile and 9-meter-high mechanically stabilized earth walls were used to handle the tricky conditions while keeping traffic moving during construction. Crews used launching girders and worked from existing structures to build the river crossings. One of the bridges was built on existing 50-year-old piers.
Location: Fort McMurray, Alberta, Canada
Cost: $450 million
Length: 4.35 miles
Designer: Stantec Consulting Ltd.
Contractors: Flatiron Constructors; Graham Construction; Innovative Civil Constructors; South Rock Construction
Owner: Alberta Transportation