The original Highway 2 culvert was once a single-lane, short-span bridge that had long culvert extensions added when the road was super-elevated by the MTO in the 1960s. The original single-lane structure had deteriorated severely; however, it was more economical to remove and replace the entire culvert than it would have been to repair the original centre section, due to being buried 11 metres below the road surface.
The depth of excavation was a significant challenge that required careful construction staging plans. The option of designing and constructing a cast-in-place structure versus a precast structure was an integral part of the engineering challenge. It was determined that designing a ‘super-box’ pre-cast culvert was the most economical and fastest method of construction. By utilizing an innovative method of installing a three-sided box culvert unit inverted on top of the lower unit, construction time was greatly reduced without requiring cast-in-place concrete.