CMC foundation for Carseland Terminal

Geopac has successfully improved, by Controlled Modulus Columns, the foundation soils of petroleum product tanks.

Geopac improved, by Controlled Modulus Columns, the foundation soils of petroleum product tanks on Federated Co-Operatives Limited’s property in Carseland (Alberta). The foundation of 16 tanks over a total surface area of 8700 m² was improved as follows:

• 3 tanks – diameter 38 m
• 6 tanks – diameter 27 m
• 7 tanks – diameter 18 m

Soil characteristics are relatively homogeneous and composed as follows:

• 3m of Clay Till #1- N_SPT = 12
• 2m of Clay Till #2 – N_SPT = 30
• 2m of Clay Till #3 – N_SPT = 50

The specifications of the treatment for load of 300 kPa are:

• A uniform settlement lower than 50 mm at the edge of the tank
• A differential settlement lower than 13 mm per 10 m of circumference

The proposed solution was to install dense semi-rigid elements, Controlled Modulus Columns (CMC), through the thickness of the clay in place (about 8 to 10 m) down to the dense clay till.

In order to achieve the set up within the time allowed, two production stations carried out the installation of over 3000 CMC’s.

The load capacity of the CMC’s was verified with load tests and performed on pre-selected CMC’s.