Anna Crockford, PEng, will present a case study on the Ottawa Light Rail project at the Association of Environmental & Engineering Geologists (AEG) 68th Annual Meeting on Wednesday, September 24, 2025 at the Westin Chicago River North, Chicago, Illinois
The Kiewit Eurovia Vinci (KEV) Partnership has designed and are nearing completion of building the Ottawa Stage 2 Light Rail Transit (LRT) Project. This 27 km extension of the Confederation Line includes 3.4 km of cut and cover tunnels and significant highway widening and structures scope. Brierley Associates supported KEV by providing temporary support of excavation system designs for various segments of the open-cut trench excavation through soils and rock. The rock along the project alignment consisted of layered limestone, dolostones and shale beds with predominantly subvertical and subhorizontal jointing. Based on top of rock data collected during prior subsurface investigation work, it was assumed that several faults would cross the alignment, although they were not mapped. Given the rock mass conditions within the project area, a spot bolting rock support system was implemented for the vertical rock cuts in combination with regular rock face mapping and monitoring.
Along one segment of the alignment, a large sub-vertical fault was exposed below the installed soldier pile and lagging shoring. During excavation, rock conditions and monitoring data indicated a potential rock slope instability in the vicinity of the fault along one wall of the excavation. The survey, engineering and contractor teams responses were coordinated to mitigate the risks to the project and personnel. Sequence of events, response successes and lessons learned will be presented.
More information and registration for the conference can be found here.