2020 CANADIAN CONSULTING ENGINEERING AWARDS
TRANSPORTATION
AWARD OF EXCELLENCE
Garrison Crossing
Pedelta Canada
“The bridges are over two of Canada’s busiest rail lines and the innovative use of stainless steel for long-term durability reduces the need for maintenance.” –Jury 40
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On behalf of Toronto, CreateTO, awarded the Garrison Crossing designbuild project to Dufferin Construction in 2015 to provide a link from the city’s Stanley Park to the historic site of Fort York and the waterfront, crossing above two of Canada’s busiest rail corridors. Pedelta served as lead designer. Construction started in August 2016 and the crossing opened to the public in October 2019. Pedelta designed two pedestrian and cycle bridges, using duplex stainless steel for the entire structure to ensure long-term durability. The crossing is designed to last at least 75 years. A tale of two bridges The structural systems selected for both bridges were similar, with the geometry differing slightly. The north bridge has a single, 52-m long span. Its arch has a maximum height over the deck elevation of 9 m and is connected to the tiegirder at both ends and by two families of inclined hangers that cross each
other once. This system allowed for relatively slender cross-sections and a lighter structure. The south bridge required its own design to accommodate a 5-m elevation difference. The best fit for the site constraints was a one-span arch connected to a V-shaped pier on the south end. This system transforms the thrust of the arch into a set of axial forces in the pier. Specifying stainless steel This project marked the first time duplex stainless steel has been used for the entire structure of a bridge anywhere in North America. Stainless steel is recognized as a sustainable material with a lower environmental impact than carbon steel, due to reduced CO2 emissions during fabrication, lightweight construction, low need for maintenance and one of the highest rates of recycling of any material. When evaluating the use of stainless steel from an investment perspective, one of the key points considered
October/November 2020
2020-10-05 9:16 AM
