TORONTO — A steel truss system designed by Acrow, an international bridge engineering and supply company, was used to provide support to Pont Perrault during the project to rehabilitate the historic covered bridge in Québec.
Pont Perrault opened to traffic in 1929 and spans the Chaudiere River in the parish municipality of Notre-Dame-des-Pins. The bridge had not been open to vehicular traffic in years and it closed to pedestrians and cyclists in 2018 after damage to timber components was discovered. At 150.9 metres long, it is the longest covered bridge in the province.
After delays due to sharp increases in the cost of building materials during the pandemic, the project began in May 2022 and was completed in November 2022.
The repair work enabled the reopening of Pont Perrault for year-round use by pedestrians and cyclists, as well as ATV and snowmobile enthusiasts.
Acrow was contacted by project contractor Cité Construction TM Inc. to design and supply a freestanding structure to fit inside Pont Perrault to provide support to the covered bridge for the duration of the restoration, indicates a release, adding the modular steel truss system was 152.4 metres long with an overall width of 2.7 metres, and a timber deck for worker access.
In addition, temporary scaffolding underneath the bridge was cabled to and supported by Acrow’s structure, allowing exterior work on the underside of the bridge to proceed safely.
The project presented a few challenges. At the design stage, the enormous wind load necessitated the fabrication of custom sway braces for the truss system.
The installation was unusual as well and required Acrow’s structure to stay in cantilever for 41 metres and at different slopes over the spans as it was pulled into place by cables across rollers, the release states.