Capilano Bridge Rehabilitation
The Capilano Bridge is a 290-metre long structure over the North Saskatchewan River which accommodates six traffic lanes (65,000 vehicles per day) and a sidewalk/bikeway. The City of Edmonton engaged ISL to carry out an assessment of the Capilano Bridge and to formulate a long-term rehabilitation strategy. In 2002, ISL began the design of a full deck replacement, deemed to be the most cost-effective repair method.
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 and Coliseum (now Rexall Place).
To help reduce construction time, ISL tendered an innovative design using precast and prestressed deck panels as formwork – which then doubled as a major structural component of the finished deck structure – with a concrete pour overtop to create a smooth, unbroken surface.
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.
A major challenge was to maintain grade control throughout the 27 concrete pours considering the different load conditions associated with each pour. During the night-time pours, traffic was reduced to two lanes, but was reopened the following morning to unrestricted traffic loading. A ducting system was also put in place for future installation of an anti-icing system.
By way of ISL's innovative design, the resulting deck is virtually crack-free with good grade control. The construction was completed in the fall of 2004.