Before redevelopment of the West Don Lands - including the Athletes’ Village/Canary District - could occur it was first necessary to implement a series of flood mitigation measures. In spring 2012, the construction of the flood protection landform (FPL) by Infrastructure Ontario was nearing completion.
The FPL is an engineering feat that is essentially a 4-metre high berm that creates a flood barrier along the west side of the Don River. It protects 201 hectares (519 acres) and an estimated $162 million in potential flood damage from catastrophic storm events. The FPL has also provided the base for Corktown Common, the area’s signature park.
One of the final pieces of work to complete the FPL was the installation of a backflow preventer on an existing storm sewer beneath the King-Queen bridge. The backflow preventer is a pipe the size of a bus that will allow stormwater to flow out to the Don River but will prevent flooding from flowing back on to adjacent lands. Without it, the FPL would be ineffective.
When excavation for the installation of the backflow preventer began, it quickly became clear to Infrastructure Ontario that the century-old bridge footings would need to be fortified before any further work could continue. The work currently underway below the bridge is required to reinforce the structure and extend the life of this important piece of infrastructure. The work is complex and takes time.
Work to-date has included the installation of a series of micro piles. Micro piles are small diameter rods drilled into bedrock adjacent to the bridge columns to reinforce the columns and support the bridge span. The micro piles are encased in a steel pipe and then filled with concrete grout for stability.
Work has also included reinforcing the existing columns and column bases. The column bases have been reinforced with large steel I-Beams where the column bases meet the back flow preventer and diagonal bracing has been installed on the columns for further reinforcement.
Future work includes pouring new concrete pile caps and incorporating them into the existing bridge footings, as well as performing work to ensure the bridge columns are level and plumb. New column bearing plates will be installed at the same time.
Infrastructure Ontario expects to complete the work in early 2015 and is grateful for the community’s patience. Infrastructure Ontario have updated the signs on the bridge and will make every effort to keep the community up-to-date on the status of work going forward.
For more information or questions about the work being undertaken at the King-Queen bridge please contact
info@infrastructureontario.ca.
