ALE Provide Bridge Support in Canada
The Champlain Bridge stretches for over 3km over the Saint Lawrence River and is one of the busiest routes in Canada, connecting Montreal and the South Shore. As the condition of the original bridge began to deteriorate, plans for a new Champlain Bridge were swiftly put in place. A challenging timeline was proposed for one of the biggest construction projects in North America.
ALE was tasked with supporting the bridge during the installation of four new segments. ALE designed a system that could support the bridge from a single location throughout the operation and didn’t need to be moved for the installation of each segment. It also would enable the client to continue construction from both the east and west sides of the Saint Lawrence River. This accelerated the installation by minimising disruption to ongoing construction activities from the west side.
The support structures included a shoring system, consisting of two ‘A’ towers, and a king post. Temporary foundations were installed 15m above the ground to support the shoring system, enabling it to support the lower deck of the new bridge at a total height of 52m.
Above this, the 36m king post was installed, connected to two of the bridge segments and one of the bridge piles by retaining hoist units.
Throughout the installation of each of the four segments, ALE controlled these hoist units as well as jacks contained within the shoring towers. These lifting systems enabled ALE to precisely lower or increase the tension as required, raising or lowering each of the bridge segments.
To perform this operation, ALE utilised six 500t capacity double-acting jacks within each shoring tower. For the operation of the king post, there were a total of four 1,250t capacity retaining hoist units; two connected to the bridge pile and two to one of the bridge segments. There were also two 900t capacity hoist units connected to another segment.
Constructed near to the original bridge, the new Champlain Bridge has a central lane solely for public transport, which will help to ease traffic congestion. While the old bridge was in use for 57 years, the new one is expected to have a 125-year lifespan.