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-Video

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Hugh Lee of Keller and Max Ho of Grounded Engineering describe diaphragm walls used in Toronto’s Port Lands Flood Protection and Enabling Infrastructure Project. The project will reshape the mouth of the Don River to reduce flooding and enable urban revitalization. Hydromill-excavated, reinforced-concrete walls were installed through reclaimed, contaminated soils and socketed into bedrock to provide earth retention and hydraulic cutoffs.<br /><br />The design-build team proposed diaphragm walls instead of the tendered secant-pile system. Stiff T-shaped panels enabled cantilever walls without lateral supports, reduced riverbank deflections, and cut construction joints by up to 80%. The alternative was estimated to save about 25% in cost and shorten construction from eight to ten months to roughly four.<br /><br />At the west plug, the walls served successively as a bulkhead, bridge support, and dam during excavation. Automated monitoring tracked wall movements in real time. Measured deflections were about 10–15 mm, with no significant leakage; the temporary plug wall was decommissioned in 2024.

Keywords

diaphragm walls

Port Lands Flood Protection

Don River

hydromill excavation

earth retention