SELECTION OF TUNNEL ALIGNMENT AND CONSTRUCTION FOR THE SHEPPARD EAST LRT PROJECT IN TORONTO

摘要

The project is an underground connection between the new LRT along SheppardrnAvenue with the existing Don Mills subway station. This underground portion consists ofrnone kilometer twin tunnels and station underneath Highway 404. This paper describesrnthe preliminary design selection of the tunnel alignment and construction. The tunnelrnwill be constructed by a combination of cut-and-cover and mined tunneling for the stationrnand highway crossing, respectively. Both sequential excavation and TBM methodsrnwere considered for the mined tunneling. Selection criteria included construction risksrnand settlement, ground improvement, cost, and schedule. Alternative TBM procurementsrnwere evaluated due to the tight construction schedule.