Pipelines

Prairie Creek Culvert Replacement

Location

Fort McMurray, Alberta

Expertise

Pipelines

Alberta Transportation retained Associated Engineering to complete preliminary engineering for the replacement of BF 76001 located on Highway 63:11, 9 kilometers south of Fort McMurray.

Highway 63 is a four-lane divided highway at this location and provides the only access to Fort McMurray.

BF 76001 consists of two culverts constructed in 1982. They comprise a 3.05 metre diameter x 130.5 metre long and 1.2 metre diameter x 122 metre long multi-plate pipes. The smaller pipe was installed 2.75 metre above the larger pipe’s invert to aid with icing issues. The culvert is located beneath a horizontal curve under approximately 9.75 metre of fill with 4:1 side slopes. The larger culvert is in poor condition with roof sagging, sidewall deflection and cracked seams. Struts were installed in 2008 to support the roof sagging. The upstream half the culvert was installed with a 6.5% gradient and downstream half a 0.4% gradient.

Project Highlights

Preliminary engineering included a geotechnical investigation, hydrotechnical investigation, and environmental assessment, including a fish survey.

Preliminary design included a review of the benefits of open cut excavation to optimize construction costs, and trenchless methods to maintain the normal operations of Highway 63. Installation of a 98 metre long 3450 mm WSP by trenchless methods with CSP end sections was recommended. Culvert to have 3.3% slope to match average streambed slope and a 0.3 metre deep boulder bed to reduce flow velocities to meet Alberta Transportation fish passage requirements.