MAY 21, 2014—MONTREAL, CANADA – The MAADI Group engineering firm, Montréal, Québec, has installed a new aluminum arched pony-truss bridge as part of the TD Place Project, in Ottawa, Ontario, Canada. The strong, lightweight aluminum bridge, designed specifically for pedestrians and light vehicles, has an overall length of 30 meters (98 feet 5 inches), and is constructed with welded, high-strength aluminum alloy that is durable and maintenance-free. The sleek bridge design features a Warren-type truss structure as the main girder, with an extruded aluminum pony-truss truss framework, aluminum side guardrails and fencing, and IPE hardwood decking that resists slipping and skidding.
The bridge has a clear width of 1,883 mm (6 ft, 2 in) between its handrails, and its handrails are located 900 mm (3 ft) above the deck, with an easy-to-grip 38 mm (1-1/2 in) handrail diameter. Stylish vertical picket aluminum fencing is 1,070 mm (42 in) in height above the deck level, and runs vertically along the bridge sides from floor decking upward nearly to the top of the bridge’s side guardrails, spaced closely together as a child safety feature, as required by the Ontario Building Code Stainless steel bridge anchors with 25 mm (1 in) threaded rods, fasteners, rivets, and screws are used to secure the bridge onto its abutments. An existing concrete abutment at the North end of the bridge is used, and a new concrete abutment has been added at the bridge’s South entry point.
The TD Place Bridge decking material is planks of IPE hardwood that are 25 mm (1 in) thick. The bridge’s dead load is 7,925 kilograms (17,435 pounds) including the decking. The pedestrian bridge’s aluminum structural components, including chords, diagonals, transversals, stringers, handrails, aluminum fencing and transition plates weigh in at 5,959 kilograms, or 13,110 pounds without the wood decking, and 7,925 kilograms (17,435 pounds) with decking.
MAADI Engineers designed thermal expansion joints at each end of the bridge to enable the bridge to expand and contract up to 50.4 mm (2 in), allowing for a temperature gradient of 70 degrees, between -35°C and 35°C (-31°F to 95°F). The typical seasonal Stadium temperatures will vary from -15°C to 26°C (5°F to 79°F).
The bridge’s camber clears a 5 m (16 ft, 5 in) height by 6 m (19 ft, 8 in) width double line roadway used for maintenance and vehicles that enter the stadium field for parades and special events. The bridge’s walking surface has a mean grade of 8 percent, varying from end to end to accommodate the vertical clearance needed for the roadway path below.
The aluminum bridge’s arched-rail architectural design blends aesthetically with its natural surroundings, and provides durable functionality. The bridge is designed to handle light maintenance vehicles that, when fully loaded, weight approximately 1,000 kilograms (2,240 pounds) each. The bridge’s overall height of 9 feet 8 inches, when combined with the 3-foot-high trailer, comprised a 12-foot 8-inch trailered bridge that was able to clear the 13-foot-6-inch standard height overpass structures encountered during transport and was able to navigate smoothly around some very tight turns en route!
A custom wide-load flat-bed trailer was used to transport the pre-assembled bridge on its three-and-a-half-hour journey over 198 km (123 miles) from the manufacturing facility to the installation site at TD Place. The bridge was pre-assembled with fusion welding of the aluminum using the GMAW process. All welding on the bridge adheres to the CSA Standards W47.2 and W59.2 (Certification of Companies for Fusion Welding of Aluminum), and meets ISO9001: 2008 Quality Standards in manufacturing. MAADI Group is Division 1 Certified with a registered Professional Engineer responsible for all welding-related activities on the bridge and the qualified welders for the bridge project.
The TD Place Bridge was installed by 4 workmen and one crane operator in just 6 hours on April 28, 2014 using a 110-ton capacity crane. The stadium bridge weighs 7,360 kilograms (16,200 pounds), with a distributed load capacity of 4.8 kPa (100 psf), concentrated load capacity of 9.0 kN on a 750 mm x 750 mm area (2,000 pounds on a 30 in x 30 in area), and service vehicle capacity up to 1,000 kilograms (2,240 pounds), with a lateral wind charge of 410 Pa (8.5 psf).
The bridge’s designers, Simon Lacasse, Eng. M.Sc.A., and Alexandre de la Chevrotière, P.E., President of MAADI Group, Inc., note, “The new TD Place Bridge is truly essential infrastructure for the new Stadium grounds. The Bridge provides fans and employees with direct and safe pedestrian access between the Stadium’s North and South stands for all Sports competitions and events. Our aluminum footbridge is aesthetically pleasing and has a sleek architectural look, with mill finish aluminum vertical picket fencing and handrails that link into aluminum railings at the South end of the bridge, and into steel guardrail at the North end. The high-strength aluminum bridge structure is maintenance-free and offers reliable daily use in all weather conditions year-round.”
The aluminum bridge structure is entirely corrosion-free and maintenance-free, eliminating the need for expensive galvanizing or painting of steel due to rust. The structure’s AA6061-T6 aluminum extrusions can withstand harsh climate conditions including ice, snow, frigid temperatures, and high winds. Aluminum is fully recyclable with very high scrap value, and retains its strength properties when reused, unlike steel. These benefits, along with efficient transport and fast installation make this aluminum bridge structure highly cost-effective and sustainable.
“Aluminum is the ideal truss and railing material to integrate with the bridge’s slip-proof Ironwood™ decking to create a pedestrian bridge that is perfect for the heavy foot traffic at this Sports venue, and for light vehicle access by maintenance staff,” said de la Chevrotière, “MAADI Group wishes to express our thanks to TD Place Architect Yasmeen Bebal, OAA, MRAIC, LEED AP of Cannon Design; Dominique Gagnon, P.E., LEED PA, Project Manager, Evan Toole, EIT, Project Coordinator, and Mario Rannou, Superintendant, at the General Contracting firm Pomerleau; the entire Transportation team at Synergie Xpress Inc.; the skilled tour driver Mario Bergeron from Transport Watson; and to our very professional and skilled welding and assembly team in Terrebonne.”