The widening of the Arch Span on the Canadian side of the Rainbow Bridge was a challenging project that was completed within a tight timeframe and under extremely challenging conditions. A large portion of the project was completed during the winter months and traffic flow on and below the bridge had to be accommodated at all times. Crews worked around the clock and much of the work was completed 200 feet below bridge level.
The bridge approach spans on the Canadian side of the bridge were widened adding 1,500 square metres of new bridge deck. The Substructure consisted of hollow concrete box piers and a hollow barrel arched concrete superstructure helped support the new bridge deck. Both the substructure and the superstructure were cast-in-place requiring extensive work below bridge level as three tall piers were constructed in the gorge and two were required near the top of the gorge. One of the concrete footings in the substructure was built into a one-to-one rock slope and required intensive construction techniques. The conditions required excavation machinery and other equipment to work in the gorge on the steep side slopes.
Extensive blasting of the existing rock face was needed to accommodate the new bridge expansion. The blasting had to be precise and well orchestrated due to the proximity of the bridge, nearby homes, and businesses. Segments of the existing bridge structure and the new construction were within eight feet of the blasting areas. In addition, no debris from the blasting was to come into contact with any portions of the existing bridge or the expansion that was in construction. The Niagara River also needed to be protected from debris entering the water. All of the debris from the blasting was contained on the slope of the gorge by custom designed and constructed barriers. Rankin Construction successfully completed this project approximately 7 months ahead of schedule to the appreciation of the Niagara Falls Bridge Commission.
