Experimental investigations of using deep mixing method to stabilise problematic clays in Ontario

Champlain Sea clay is a sensitive marine clay which can lose more than 90% of its strength when disturbed. Organic silty clay, commonly found in Ontario, has a high compressibility and a low shear strength. In this experimental study, different binders were applied to Champlain Sea clay and organic silty clay to improve its strength properties. The results indicate that cement and slag/cement can significantly improve the strength of these problematic clays. A cement dosage ranging from 150 kg/m3 to 250 kg/m3 can consistently improve the undrained shear strength of Champlain Sea clay and organic silty clay with the maximum strength improvement ratio of 10 and 18 respectively. A slag/cement dosage of 290 kg/m3 with a mass ratio of 3:1 can improve the undrained shear strength of Champlain Sea clay for more than 50 times. Lime was found to be effective in treating organic silty clay as well.