The Pinawa Bridge over Winnipeg River near Pinawa, Manitoba, built in 1961, is a vital link to the
community of Pinawa, the Manitoba Hydro Pointe du Bois Generating Station, and AECL’s Whiteshell
Laboratories. The structure accommodates two traffic lanes on four 42.7m main spans and two 30.5m
approach spans. The bridge superstructure comprising of five steel plate I-girders and reinforced concrete
deck, is continuous over the piers with hinges in spans 3 and 5. Finger plate expansion joints above the
hinges accelerated deterioration of the underlying deck soffit, steel girders, and pin-hanger system.
Rehabilitation works were required to extend the remaining service life due to deterioration of several key components. The major rehabilitation work items included:
Replacing existing pin-hanger connections with girder continuity splices to make the bridge fully continuous;
Replacing existing rocker bearings with pot bearings to accommodate the change in behavior of the superstructure;
Constructing a partial depth deck replacement, widened to current geometric design standard;
Installing girder cover plates to increase the design live load and to enable deck widening; and
Associated road works to accommodate widened bridge geometry.
The project presented challenges to Manitoba Infrastructure and Transportation (MIT) and to the design team in ensuring that the rehabilitation works occurred in accordance with the design and staging requirements. Challenges encountered during construction works included:
Staging of construction works to maintain at least one traffic lane at all times;
Installing continuity splices in areas of severely corroded and/or distorted girder steel;
Reviewing contractor’s staging techniques to allow concurrent continuity splice installation and
deck demolition works; and
Completing staged partial depth deck construction in Manitoba winter conditions and constructing the widened deck section profile.
The rehabilitation works were completed successfully and will increase the bridge service life by 40 years and meet current design standards.
