The construction of the future Vaudreuil-Soulanges hospital has intensified in recent weeks with more equipment and workers on site as the foundation work begins.

The preliminary excavation for the hospital's two pavilions is complete and workers are crews are now drilling and inserting concrete caissons on site, according to an update from the Centre intégré de santé et de services sociaux de la Montérégie-Ouest (CISSSMO).

The hospital is located at the junction of Highways 30 and 40. 

564 caisson piles  

The Vaudreuil-Soulanges Hospital project is being built using 564 piles making it the largest caisson pile project in North America at this time.

The piles range from 1.2 to 1.5 metres in diameter will be inserted at depths up to 23 metres to form the foundations of the two pavilions at the future hospital. 

The piles are long cylinders that are driven deep into the ground to provide a stable foundation for structures when shallow foundations are inadequate due to the weight-bearing capacity of the soil. 

Pile construction procedure 

A temporary caisson is installed at a depth of approximately 15 to 20 meters through layers of clay and till.  

The inside of the temporary caisson is hollowed out using an auger, an instrument with a spiral bit designed to drill into the ground. The caisson is then sealed and the socket is drilled into the rock.

The rock walls and pile bottom are cleaned using a high-flow pump. Once completed, the pile is rigorously inspected and filled with clear water to compensate for artesian pressure. 

The team then installs the reinforcement and cements the pile using a concrete pump with a hopper immersed from the bottom. The temporary caisson is then removed as the concrete rises. This sequence is repeated for each of the 564 piles that will be drilled into the ground.  

"The next few months will be busy. We're delighted to see the work progressing and taking shape. We're getting closer to our final objective and are confident about the future," says Martin Ouellet, Director of Major Infrastructure Projects at the CISSS de la Montérégie-Ouest.