Little Bras d'Or Bridge Replacement, Cape Breton, NS

 

The innovative girder erection approach developed for the replacement of the Little Bras d’or Bridge involved assembling the steel box girders on the West approach of the bridge and longitudinally launching them into position across the channel. The approach minimized the use of expensive cranes and allowed for minimal impact on the sensitive watercourse. To shorten the cantilever length to 30 m during construction, and thus limit the compression stresses in the wide / unstiffened bottom plate and the buckling stresses in the girder webs, temporary supports were designed between the center pier and both the east and west abutments. The temporary supports each consisted of 22 m long steel box trusses supported on the south end by a steel saddle beam and single pipe pile braced back to the temporary trestle and driven to refusal in bedrock, and by a gantry system that was supported from the east and west piers of the existing bridge. HEC ensured that the existing piers were capable of withstanding the load effects resulting from girder launching operations while traffic remained on the existing structure.

Client: Cherubini Metal Works

Value: $11 M (Full Bridge Replacement)

Year: 2010

Role: Preliminary and Detailed Bridge Designers