Controlled Modulus Columns (CMCs)
Building A of the Leeswood project involved the construction of a new distribution center located on lot 6 402 840, rue Turnbull, near Highway 30 in Beauharnois, Quebec. Due to the compressibility of the soils and in order to limit total and differential settlements, the Controlled Modulus Column (CMC) system was chosen as the best solution for reinforcement to support the slab and the foundations.
The stratigraphy of the site was composed of 3 distinct layers before reaching the rock:
- Topsoil with a thickness of 0.10m to 0.20m on all the boreholes drilled by GHD (2022) and Solroc (2021).
- An embankment with organic matter with a thickness between 0.6 and 4.00 m
- A silty clay deposit between 16.89 m and 19.82 m thick in BH-08 and BH-09. The silty clay deposit was to be divided into two distinct sections:
- A clayey crust with a thickness of 3 meters;
- A soft to firm clay with a thickness of approximately 13.8 to 16.8 meters;
- A glacial till was intercepted directly under the silty clay in borehole BH-09. The rock was drilled in boreholes BH-08 and BH-09 to a thickness of 1.5m to 2m