Deconstruction of the original Champlain Bridge

Section 7 : Brossard

Fall 2022 – Stage 1: mid-September to November

• Preparatory work for the deconstruction of the spans over Highway 132, mainly trucking for the transportation of granular materials
• Removal of the modular trusses
• Deconstruction of the spans over Highway 132 (end of October/early November depending on work progress and weather conditions)

Anticipated Impacts:

• Traffic: 6 weekend blitzes between September and November from Friday, 11 p.m. to Monday, 5 a.m. + complete night closure during the week in September only
  • complete closure of Highway 132 OR complete closure of Marie-Victorin Boulevard, either in one direction or in both directions at the same time
  • By default, during closures on Marie-Victorin Boulevard, the exit and access ramps in the impeded areas will be closed
• Continuous day and night work
• Impact and operation noise / Possible exceedance of noise criteria at night
• Visible dust in the vicinity of the site
• Trucking and storage of materials

Mitigation Measures:

• Simulation of the works before blitzes ​
• Use of hammers with noise suppression (5 to 10 dBa reduction)​
• Noisier work performed during the day​
• Temporary acoustic barrier/panel made up of trucks (over 210 m)​
• Monitoring of noise levels by real-time sound level meters
• Use of water cannons to reduce dust
• Real-time monitoring of air quality

Fall 2022 – Stage 2: October 2022 to April 2023

• Deconstruction of the spans on the Brossard jetty
• Treatment of the concrete floor on the jetty

Anticipated Impacts:

• Noise from impact and daytime operations for several weeks (October 2022 to April 2023), in compliance with criteria
• Visible dust in the vicinity of the site
• Storage of materials
• Trucking during permitted hours   

Mitigation Measures:

• Simulation of the works before blitzes ​
• Use of hammers with noise suppression (5 to 10 dBa reduction)​
• Noisier work performed during the day​
• Temporary acoustic barrier/panel made up of trucks (over 210 m)​
• Monitoring of noise levels by real-time sound level meters
• Use of water cannons to reduce dust
• Real-time monitoring of air quality

Section 5 : St. Lawrence River

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

1. The piers are deconstructed from top to bottom using hydraulic percussion hammers installed on the excavators.
2. Two barges are needed to deconstruct a pier.
3. The barges are attached together to recover the debris.
4. The debris is recycled at authorized recycling centres.

It takes about 10 days to deconstruct each pier.

Deconstruction steps: footings

1. Two barges assembled into an “L” shape surround the footings, which are retained with sheet piles.
2. Once the sheet piles are in place, excavators with GPS positioning systems extract the footing from the bed of the St. Lawrence River.
3. 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.  

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

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:

1. To lift a component from the bridge, engineers have to identify and calculate the weight to be lifted.
2. Once the weight is determined, cutting lines are painted onto the component.
3. The component is attached to a crane, and crews on the bridge deck cut the steel into pieces.
4. Finally, the component is lowered and placed on the jetty by the crane.
5. The materials are sent to authorized recycling centres.

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.

• 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.