100 Avenue Bridge Rehabilitation
Grande Prairie, AB
The City of Grande Prairie selected ISL for this bridge rehabiliation project, which involved structural assessment and recommendation of rehabilitation options, followed by design, tendering and construction administration for the selected option.
State of Disrepair
Built in 1958 with only small fixes thereafter, the 100 Avenue Bridge was in a state of disrepair with reinforcing bar corrosion and numerous spalls of concrete along the deck curb. Bridge expansion joints were buried under six inches of Asphalt Concrete Pavement (ACP).
Inspections and assessments led ISL to recommend replacing the 39.5-metre long deck and rebuilding the wing wall, guard rail, abutments, bearings and approach slabs. Construction staging enabled two lanes of traffic to remain open for most of the construction, even though the work was extensive. A new High Performance Concrete (HPC) topping slab will increase the deck's durability and service life.
Analysis showed that the existing girders complied with bridge code loading, allowing ISL to develop a plan for girder reuse by rehabilitating their corroded ends. Construction efficiencies were maximized by lifting the girders and rehabilitating them off their supports, which enabled access to the abutment/piers for its rehabilitation at the same time. These measures resulted in substantial time and capital cost savings for the City.
With the completion of these rehabilitations in December 2014, the service life of the bridge has been extended by 50 years or more.