Design of a Remarkable Bascule Bridge Over an Historical Canal

The Gouin bascule bridge is a 1,300 tons gigantic steel structure that allows pleasure boats to enter the Chambly Canal National Historic Site and provides access over the Richelieu river for vehicles, cyclists and pedestrians. As part of a project to revitalize and modernize the city centre, the architectural concept of the movable bridge will provide a landmark to this highly touristic site. There are only few examples in the world of such movable bridges with a large suspended counterweight. The challenges of the project include strict architectural criteria, fabrication and alignment of over 800 mm in diameter pins, the assembly on-site of remarkably large bridge parts and the precise balancing of the bridge.

When designing this structure, WSP made sure to consider the non-redundant aspect of some parts of the structure. Details regarding the design of the stays supporting the entire upper structure and the hydraulic cylinders initiating the rotation are described in this paper. The planning of the works in the middle of the critical infrastructures and services surrounding the bridge is explained. Since no interruption of the navigation on the canal was allowed during construction, some special considerations had to be taken with regards to the works at the foundation units.