To keep Lakeshore West GO Trains running smoothly through the station at Port Credit while tracks for the Hazel McCallion Light Rail Transit (LRT) line are laid underneath, Metrolinx’s contractor, Mobilinx, will use the construction method called the Verona System.
Mobilinx will use three temporary bridges below the existing tracks before laying new underground LRT tracks and installing the permanent foundations for the street level GO tracks.
In the first step, the push box was built. This is a large concrete structure that will serve as the underpass for light rail vehicles traveling under the Lakeshore West Line. It includes a partition wall separating north and southbound vehicles.
The box was built in an open area, benefiting customers by keeping this part of construction away from the GO line. Placing it under the existing tracks while minimizing disruption is the goal.
Next, four rows of micropiles (very strong pieces of metal used for a foundation) along with pile caps will be installed along the existing GO tracks at the station. Once completed, 11 beams in trenches under those tracks will span the four rows of micropiles. After the beams are in place, three temporary modular bridges – one for each current street-level track – must be created to hold those tracks up during the next stage.
To get the box in place, crews will use an approach called box-jacking, pushing it underneath the GO tracks while excavation work clears a path for it.
The three temporary bridges will support the street-level GO tracks, while the box is being jacked. Afterwards, those bridges will be removed, and the train loads will be safely transferred to the top of the push box.
The Verona System minimizes impact on train schedules, work time at the station, noise and pollution. It also improves overall productivity of construction and quality of the infrastructure. Most of this work in Port Credit will be done at night to further reduce the impact on customers’ travel.
“This is the first time a Verona System is being deployed in Canada,” said Mobilinx Assistant Project Manager Gavin Lobo. “This innovative technique designed by Petrucco will ensure minimal disruption to train service while the push box is installed.”