Abstract Manager

Egis (formerly Mcintosh Perry) was tasked with saving the 74-year-old Touchette Bridge over the South Nation River near Casselman Ontario, Canada. The bridge was a 73 m long single span Parker through truss bridge with a timber deck on steel stringers supported by steel floor beams. 

The bridge was in poor condition with severe section loss in the steel deck system and had extensive delaminations and spalls on its abutments. The poor condition had limited loads on the structure to 15 tonnes and was on the brink of closing. The client tasked Egis with designing a rehabilitation that would restore normal loading conditions and extend the service life of the bridge by more than 25 years.

During Egis’ initial site visit, the bridge team noted that the ends of the truss were pushing into the bridge abutments and the uni-directional pot bearings had exceeded their movement capacity. These unexpected concerns made salvaging the bridge more difficult. The bridge team had to find a way to stabilize the abutments from further movement and stage replacement of the truss decking system to prevent the trusses from buckling.

This project is a great example of the challenges that small Municipalities have with large bridges and the economic challenges of keeping them open.

This presentation/paper will discuss the analysis of the truss and substructure, the stabilization of the abutment and the carefully engineered construction sequence that was developed to complete the $4.5M rehabilitation.