Design and Construction of St. Patrick's Pedestrian Bridge in Calgary

St. Patrick's Bridge crossing the Bow River in Calgary is currently under construction and will be reaching completion at the time of the conference. The bridge is the result of an open international competition won by a joint venture between RFR architects and engineers, and Halsall, now part of the Parsons Brinckerhoff group.

The footbridge is a three-span, 182 metre long network arch structure spanning over the Bow River at the tip of St. Patrick's Island in Calgary. The inherently efficient scheme with generous span to depth ratios was optimized parametrically with respect to member geometry and sizes. The slender arches and slim deck have minimal contact with the river banks thereby responding to the openness and the natural qualities of the site.

Several challenges were encountered during the course of the construction, the most significant of which was the unprecedented flooding of June 2013 that washed out critical deck falsework, and caused extensive damage to the bridge deck and steelwork. Finally, the design itself presented certain construction challenges such as the sequencing of installation operations and hanger cable tensioning so that the arches and deck work together as a network arch.