A unique application of Diaphragm Wall to facilitate the excavation of New River Channel on The Port Lands Flood Protection and Enabling Infrastructure Project in Toronto, Ontario-Presentation Video

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Video Summary

Hugh Lee and Max Ho describe the use of diaphragm walls on Toronto’s $1.25 billion Portland Flood Protection Project at the Don River mouth. The project replaces a former industrial flood-prone area with a more natural river outlet and future development space. Diaphragm walls, excavated with hydro mills and slurry support, were chosen over the original secant pile design because they offered greater stiffness, better verticality, faster construction, and lower cost.<br /><br />The walls served multiple roles: temporary earth retention, a hydraulic cutoff to isolate contaminated soils, a dam during river excavation, and support for bridge installation. The west plug wall was especially complex, acting through several construction phases before being decommissioned. North and south walls remain as permanent cutoff walls. Monitoring showed only 10–15 mm deflection, no major leakage, and successful performance through Toronto’s extreme temperature range.

Keywords

Toronto flood protection

diaphragm walls

Don River

hydro mill excavation

hydraulic cutoff