Beauharnois Bridge foundations complete
By Richard High05 May 2010
A Spanish-Canadian consortium has used Bauer foundation rigs to complete the Beauharnois Bridge project in Quebec, Canada.
The bridge is part of Highway 30, a CA$ 130 million (US$ 126.6 million) project that aims to complete the highway with the addition of a new 42 km-long, four-lane western segment between Châteauguay and Vaudreuil-Dorion, including a 7 km-long highway connection.
The western segment required the construction of two major bridges, one across the St. Lawrence River and one over the Beauharnois Canal. The Government of Quebec oversaw construction and retained ownership of the additions, including the two bridges.
Bauer Foundations Canada constructed the foundations of the Beauharnois Bridge. The CA$ 30 million (US$ 29.2 million) contract involved construction of 138 bored piles: 60 on land for the bridge thrust blocks, and 78 in the water, from a pontoon, for the pillars.
Five drilling rigs were used: three Bauer BG 40 and two Bauer BG 28 units.
To ensure pinpoint accuracy during drilling, an IB 10 rig was used to pre-drill to a depth of 4 m into the rock. The 2 m-diameter piles then socketed 4.5 to 5 m-deep into the rock, although sometimes, depending on rock quality, this was deeper.
During the geotechnical investigation the rock was proven to be extremely hard. Some of the rock cores' compressive strength was above 300 Mpa.
The Beauharnois Bridge crosses the Beauharnois Canal, a bypass of the St. Lawrence Canal and part of an international network linking Canada's Great Lakes with the industrial region of Detroit, Milwaukee and Chicago with the Hudson Bay and the Atlantic.
The Beauharnois Canal was originally blasted out of hard rock back in the 1930s, in order to make the St. Lawrence Canal passable for shipping. Downstream, the two canals converge at a lock, the location of the new Beauharnois Bridge.