The new Autoroute 30 project consists of the completion of the western portion of A-30 over a distance of 42 kilometers between Chateauguay and Vaudreuil-Dorion (QC). The road alignment crosses over the St. Lawrence River and the St. Lawrence Seaway at Beauharnois. Due to poor soil conditions at the eastern approach of the Beauharnois Canal Bridge, Controlled Modulus Columns (CMC) were used to improve the bearing capacity of the underlying soft soil, ensure slope stability and to reduce post construction settlements. This part of the project was critical as the embankment was used to launch the bridge spanning the canal. This article presents the specifics of this particular project and the CMC technology. Design considerations and calculation concepts are explained including finite element analysis and verification of resistance of the rigid inclusions in a seismic event.
