Transportation: Beauharnois Canal Bridge

The Beauharnois Canal Bridge, part of the last leg of Autoroute 30, opened to the public on December 15, 2012, completing a massive highway project that started construction in 2009 but has its genesis in the 1960s.

The final western section of Autoroute 30 runs from Vaudreuil-Dorion to Chateauguay, bypassing Montreal via the south and providing a corridor to the Montérégie region. It is a four-lane tolled highway that has cost a total of $1.5 billion. Arup was lead engineer for this western section, including the bridges.

The $750-million Beauharnois Canal Bridge is one of two major crossings along the highway. The bridge spans over the St. Lawrence Seaway, the main shipping route between the Atlantic Ocean and the Great Lakes. It is a 2.5 kilometre-long structure with a gradient of 3.5% that provides the necessary 38.5 metres of clearance above the shipping canal in the Seaway.

The bridge’s eastern approach superstructure, including the navigation span, is a continuous steel-concrete composite box girder. As of today, the bridge is the second longest incrementally launched bridge in the world, with a total launched length of 1,446 metres, a figure only exceeded by the Millau Viaduct in France.

The western approach has a total length of 1,095 metres, with intermediate expansion joints. Constructed with 2-metre deep NEBT beams, the 45-metre spans are among the longest ever achieved in pre-stressed bridge construction in North America.

Within the canal, the footprint of the bridge had to be minimized, both to limit the loss of fish habitat and also to minimize any head-loss in the river flow that might affect a hydro-electricity dam downstream. To achieve this, the bridge in this section has 82-metre spans with pile caps that lie above the water level.

Rather than relying on the Canadian Highway Bridge Design Code’s more conservative approach, Arup analyzed the soil conditions in a seismic response model at each of the bridge’s foundations. The specific soil properties varied significantly along the length of the bridge, so this method resulted in a more accurate and efficient design and yielded important cost reductions.

Arup is the designer to S.E.N.C. Nouvelle-Autoroute-30, the public-private international consortium that has a 35-year contract to design, build, operate, finance and maintain the entire highway and its structures.  

cce

Name of project:

Beauharnois
Canal Bridge, Highway 30, Montreal

Client:

S.E.N.C. Nouvelle-Autoroute-30 (Dragados Canada, Acciona
Infrastructures Canada,
Aecon,Verreault)

Bridge design, geotechnical,
project management:

Arup Canada (Doug Balmer, Don Phillips,
Andrew McAlpine, Roger Wood)