A new phase of the bridge deconstruction that will begin in the coming weeks will require a new deconstruction method. The teams will begin work to remove the bridge piers (or its “legs”) and the footings that sit under water. 
 

This operation will be carried out with specialized excavators on barges that will serve as a work surface for crews to remove concrete debris toward the Île des Sœurs jetty.

Photo: Deconstruction of a Champlain Bridge pier.

Deconstruction of the “legs”

The “legs” will be deconstructed from top to bottom using hydraulic percussion hammers installed on the excavators. The work barges will be placed in the same location to recover all of the deconstruction debris. This will keep the debris from impacting the environment before it enters the material recycling process.

The two barges used for the piers are 210 feet by 144 feet.

Removal of the pier footings

Two barges assembled into a “C” shape will surround the footing to be removed, which will be retained with sheet piles. Once the sheet piles are in place, excavators with GPS positioning systems will extract the footing from the bed of the St. Lawrence River. The space in the bed left by the removed footing will be restored with stone fill, and the sheet piles will be removed.

This operation will be repeated for all 34 footings in the Greater La Prairie Basin.

Photo: Removal of a Champlain Bridge footing.