The City engaged ISL in 2000 to carry out an assessment of the Capilano Bridge and to formulate a long-term rehabilitation strategy. The life-cycle analysis, including user costs, identified full deck replacement as the most cost-effective repair method. The City then retained ISL in 2002 to provide preliminary and detailed design, tender package preparation, construction inspection and contract administration, and post construction services for the bridge rehabilitation.

The Capilano Bridge is a 290m long structure over the North Saskatchewan River which accommodates six traffic lanes (65,000 vpd) and a sidewalk/bikeway. A major challenge was staging the work to minimize impact on traffic. This was successfully achieved by maintaining four travel lanes on the bridge with visual screening throughout the construction area to minimize driver distractions. The four lanes operated from 6 AM to 8 PM throughout the construction period, with longer hours to accommodate major events at Northlands Park. A second challenge was to maintain grade control throughout the 27 concrete pours considering the different load conditions associated with each pour.

Two designs were tendered. One design was conventional, while the second was an innovation aimed at reducing construction time. It incorporated precast prestressed deck panels as formwork which then doubled as a major structural component of the finished deck structure. The prestress in the panels was designed to carry the temporary loading condition during slab placement, while rebar through the panels (hooked over the supports) was designed to carry the permanent load through arching action within the deck. The contractor initially used his own forming system, but later switched to the designed precise panel option to speed construction. During the night time pours, traffic was reduced to two lanes, but was reopened the following morning to unrestricted traffic loading. The resulting deck is virtually crack-free with good grade control. A ducting system was installed for future installation of an anti-icing system. The construction was completed in the fall of 2004 at a cost of $7.2 Million.

Location: Edmonton, Alberta

Completion: 2004

Contributing ISL Disciplines:

• Structural Engineering
• Urban Roadway Engineering