The evolution of the work on the West Approach of new Champlain bridge
The west approach extends from L’Île-des-Soeurs to the rear span of the cable-stayed section of the bridge. The west jetty, which was the first work platform created for the project, has changed a lot since the ground was broken in June 2015. It is a hive of activity, with several different work areas, including the one being used for the prefabrication of the concrete footings, which are the very foundation of the bridge.
To keep them protected from the weather, each of the four footings’ production lines are covered by super domes and are working at full capacity.
The journey of a footing
Each footing requires a form, with a rebar cage and post-tension loops installed in it, in preparation for the concreting operations, which last five or six hours. Once the concrete is poured, the footing rests for three days in its form, to give the concrete time to harden.
The footing is then removed from the form and moved to the second position in the production chain, using a super transporter (now called “Thor la fourmi”), which can lift parts weighing up to 1000 tons. The next step is to add a pier base, which is cast in place at an angle above the footing.
At the third and last station, the operation is finished with the installation of a work platform and the accessories required for the subsequent installation operations in the river.
The finished unit will be about 14 metres tall and will be moved to the loading dock at the end of the west jetty. As a last step, an industrial catamaran, specially designed for this purpose, will carry the unit to its place at the bottom of the river. Marine excavation work has been underway for a few months, to prepare for this important step, which will begin sometime in May.
Footings by the numbers:
Average size of the footings
11 metres by 11 metres by 2 metres high
Quantity of concrete per footing
About 250 cubic metres
Quantity of steel rebar per footing
About 40 metric tons
Number of footings prefabricated