Les exposés écrits du congrès ont été publiés dans la langue dans laquelle ils ont été soumis à l’ATC.
A rapid bridge replacement (RBR) method was designed and utilized for the replacement of five overpasses along Highway 417 at Rochester Street, Booth Street, Percy Street, Preston Street, and Bronson Avenue in Ottawa. The current paper focuses on the replacement of the overpass at Bronson Avenue which involved the replacement of two rigid frame structures, supporting eastbound and westbound lanes (EBL and WBL), separated by a 20 mm expansion joint gap.
The existing concrete rigid frame structures were demolished in place while preserving the existing footings, with excavation being performed in parallel. The new structures were prefabricated in staging areas near the sites and transported to their final locations using specialized heavy-lift equipment, including self-propelled modular transporters (SPMTs). The new rigid frames were founded on top of the existing footings.
Several replacement alternatives were studied, including staged construction, rapid bridge replacement with a composite steel girder deck, and the construction of a secant wall behind the footings during nightly closures. It was concluded that the engineering and construction costs for a rigid frame RBR alternative is the lowest cost among feasible alternatives and had the least impact on traffic.
A three-dimensional, linear elastic finite element analysis was conducted to ensure the strength and stability of the structures during lifting, transportation, and final backfilled service conditions. This presentation discusses the challenges encountered during the design and construction of the structure and the solutions implemented to address them. The construction was successfully completed in July 2023.