An inclined arch design by a team of RFR and Halsall Associates has beaten a strong international field of 33 entries to win the conceptual competition for the St Patrick's Bridge in Calgary, Canada.
RFR and Halsall had said that one of the primary goals of the concept was to keep the supporting bridge structure located primarily above the deck. This means that the bridge is supported only from land, minimising occupation of the river corridor both during construction and after completion.
The rhythm of the varying continuous arches is designed to be aligned with the river channels and the island, synchroning with the surrounding environment. The arches are inclined laterally giving a feeling of a partial enclosure for pedestrians over the river channels while remaining below deck on St Patrick's Island to open up views.
Limiting the number of elements in the flood zone also improves resistance to floods and ice floes, said the submission. In addition, the leaning arch geometry facilitates arch, hanger and strut inspection.
Calgary Municipal Land Corporation had also shortlisted a cable-stayed crossing by Buckland & Taylor and Kitchell Architecture & Design and a stress ribbon bridge by Arup with Falco Schmitt Architects.
Detailed design work will now begin as well as public consultation on the rejuvenation of St. Patrick's Island.
