King Road Grade Separation Accelerated Underpass Construction by Jacking

Author(s) J. Pittsinger, R. Doucet
TAC 2014


The project team designed an innovative strategy for the King Road Grade Separation which involved constructing a reinforced concrete tunnel structure ‘off-line’ of a major rail corridor, and subsequently sliding the completed four-track tunnel into place using an open-cut tunnel-jacking methodology. The slide utilized a one of a kind low friction, sliding base assembly. The structure was pushed into place under a fraction of the structure’s weight using a system of hydraulic jacks. This methodology allowed for a significantly abbreviated shutdown of mainline tracks over a single 72 hour period, minimizing operational impact to CN, Metrolinx and VIA trains.