Conceived with the goal of revitalizing the area near the Toronto Waterfront and bringing communities closer together, these two bridges connect Stanley Park to Fort York across two railway corridors.
Pedelta worked as an exclusive design team leader and was also involved during construction, providing technical assistance until completion of the project in late 2019. Pedelta’s proposal was selected by Build Toronto in a RFP process. It included a unique design for the Garrison Crossing bridges consisting of two tied stainless-steel network arch bridges. Both bridges span the rail corridors almost perpendicularly to minimize the crossing distance, which leads to a 52 m span for the North Bridge and 44.5 m span for the South Bridge.
Each bridge is supported by a single arch rib inclining at 18° to provide a slender, transparent and elegant impression. The two arches tilt in opposite directions, and the overall layout resembles a Yin & Yang shape to emphasize both contrast and continuity, expressing a modern, understated and elegant aesthetic. The innovative bridges are based on the company’s aesthetic philosophy of “Complex Simplicity”. Pedelta received the 2019 CISC Award of Excellence for these bridges.
Pedelta’s proposal represented an unprecedented technical innovation in North America: the use of Duplex stainless-steel on the entire structure. This pioneering use of a forefront technology provides premium aesthetics within a unique setting in addition to a safe and durable asset for the community. The structure has an extended life cycle, is more corrosion-resistant and requires less maintenance, reducing its overall cost.
The design has been focused on both structural efficiency and pleasing proportioning of the geometry, resulting in a span-to-rise ratio of around 6 and a span-to-arch depth ratio of around 100. Both bridges use trapezoidal cross sections for the girders that make up the deck and triangular cross sections for the arch ribs.
The bridges are designed to add a distinctive visual element with clear vistas to Toronto and neighbourhoods without dominating the city skyline. To accommodate the 5 m elevation difference between the ends of the South Bridge, a curved landing was designed to gracefully connect the bridge to adjacent paths. This approach ramp offers a constantly changing panoramic view over Garrison Common and Fort York.
The bridges were installed with a big crane to avoid track closures.
Stainless steel, Inclined network tied arch