Jetty: The jetty allows the dismantling of structural elements of the bridge in areas on the shore where the use of barges is not possible due to the shallow water.
Pier: The pier of a bridge, or the “leg”, is an intermediate support supporting the deck of the structure.
Footing: A footing of a bridge, or the “foot”, is the base that takes up the loads of the bridge.
Abutment: The abutment of a bridge is the part located on the shore intended to support the weight of a deck.
Deck: The deck of a bridge is a load-bearing structure that supports the loads of road traffic.
Span: The span of a bridge is the part between two piers or between a pier and an abutment.
Pier cap: The pier cap of a bridge is the upper part of a pier when the deck rests on it by means of one or more supports.
Section 5 : St. Lawrence River
Lowering of the spans
The “River Giant” continues the descent of the 30 spans of the original Champlain Bridge in the maritime sector. When fully deployed, these towers allow the work platform to reach the height of a nine-story building.
Photo. The six lifting towers raise the span (September 2021).
For the next spans, the deconstruction cycle—from recovery by the lifting system and the deconstruction on the platform to the removal of waste by barge—will take an average of about seven days.
However, weather conditions, and specifically strong winds and heavy precipitation, could extend this cycle by a few days.
Removal of piers and footings
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.
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
Lowering of the suspended span in January 2022
Preparatory work for lowering the suspended span above the Seaway is underway to begin this delicate operation in January 2022.
The original Champlain Bridge has slowly disappeared from the Montreal landscape over the past 18 months. In January 2022, the “heart” of the bridge, or its main steel span over the St. Lawrence Seaway, will be separated from the structure it has been attached to for nearly 60 years.
A first in Canada
This 2,200-tonne span will be removed and lowered onto a two-barge assembly using six strand jacks installed on temporary support girders. Heated enclosures will surround the strand jacks to protect them from the wind and keep them functional.
This complex and delicate operation is a first in Canada, as it is being done during the winter when commercial shipping activities on the St. Lawrence Seaway are halted.
The main span’s journey
It will take many hours to take down the main span, and the exact amount of time will depend on the weather conditions. Once positioned on the barge, the span will be moved along the Seaway to the temporary storage site, where it will be dismantled in spring 2022. The materials from the span will in turn be transported to specialized companies to be recycled.
Subsequently, NHSL will install temporary towers under the cantilever span of section 6 on the Brossard side and begin deconstruction.
Section 7 : Brossard
Work will begin in spring 2022.
All works may generate trucking, noise due to the deconstruction work and the off-site transportation of materials, dust emissions and occasional local traffic hindrances.