The deconstruction teams have begun work to remove the piers and footings using specialized barge-mounted excavators. The barges will be used as a work space and will help the teams take concrete debris toward the quay berth of the Île des Sœurs jetty.
Work on the river will continue until summer 2023. To date, 38 piers and 26 footings have been deconstructed between Île des Soeurs and the St. Lawrence Seaway. (Update September 2022)
Deconstruction steps: piers
The piers are deconstructed from top to bottom using hydraulic percussion hammers installed on the excavators.
Two barges are needed to deconstruct a pier.
The barges are attached together to recover the debris.
The debris is recycled at authorized recycling centres.
It takes about 10 days to deconstruct each pier.
Deconstruction steps: footings
Two barges assembled into an “L” shape surround the footings, which are retained with sheet piles.
Once the sheet piles are in place, excavators with GPS positioning systems extract the footing from the bed of the St. Lawrence River.
The space in the river bed left by the removed footing is restored with stone fill, and the sheet piles are removed.
It takes about 20 days to remove each footing.
Construction of the temporary jetty
Nouvel Horizon Saint-Laurent (NHSL) is partially removing the jetty on the Île des Soeurs side, in the section adjacent to the Estacade entrance to recover materials that are no longer needed.
These materials will be used to complete the seaway dike jetty to reduce the need to bring new materials from quarries, which will decrease trucking in the network surrounding the project and lower greenhouse gases.
Also, when the jetty is removed, NHSL will begin the deconstruction of the three footings located under the jetty.
Section 6 : Seaway
Deconstruction of the cantilever section
The deconstruction of the cantilever of the east span (on the Brossard side) has begun and will continue until December 2022.
130 steel components to be cut and lowered
Approximately 130 steel components remain to be cut and lowered with a crane onto the jetty from the cantilever section of the bridge’s east span (Brossard side).
The 5 steps of a lifting operation:
To lift a component from the bridge, engineers have to identify and calculate the weight to be lifted.
Once the weight is determined, cutting lines are painted onto the component.
The component is attached to a crane, and crews on the bridge deck cut the steel into pieces.
Finally, the component is lowered and placed on the jetty by the crane.
The materials are sent to authorized recycling centres.
On average, about ten lifting operations can be done per day depending on the weather.