Submission #16 CLOSE
DeJong Design Associates Ltd. and KTA Structural Engineers (Calgary)
Our ëSà Turn Bridge was designed to provide a walking experience across the Bow River. The view constantly changes across the distinctive curving form in contrast to the static horizon point experience typical of straight run pedestrian bridges. The galvanized ribs give the bridge deck a boat-like structure, which was inspired by the use of boats to cross rivers before bridges were commonplace.
At the island, we have positioned the bridgeÃs main structure (the concrete arches) away from the walking deck to permit as many of the existing trees to be preserved around the bridge deck as possible. This creates the unique sensation of walking through the tree tops.
The ëSà Turn Bridge consists of 26 identical, prefabricated modular units comprised of steel and concrete, which are united by a poured-in-place structural concrete deck. Some advantages of modular construction are the ability to fabricate offsite, as well as the speed with which onsite assembly can occur. Tying all the modules together is the centre deck unit with its lookout point and integrated ramp leading to St. PatrickÃs Island. Each module is supported by galvanized steel ribs, which are held up by suspension cables radiating from the twin arches.
The arch is an iconic bridge element that we worked to utilize in a non-traditional manner. After numerous design iterations, we found that placing the arches perpendicular to the bridge, and then splitting them so that each arch could support the respective bridge deck to which it tilts towards, provided an essential anchor both visually and structurally balancing the bridge. Centered between the arches of the bridge is a 5% gradient ramp to allow access to the island. Opposite the ramp entrance is a lookout point oriented toward downtown Calgary. Rather than the deck being purely utilitarian in function ̱ to get to the other side Рour intent is to provide an area for viewing and contemplation.
