LAUSR

AbstractTo investigate the effect of the changes in the soil suction on volume changes, expansion index, swelling pressure, shear strength and the coefficient of permeability, small-scale experiments were conducted on pure bentonite and bentonite mixed with sand with proportions of 30, 40 and 50% at different initial water contents and dry unit weights that were chosen from the compaction curves. In addition, large-scale model of soil with dimensions (700 × 700 × 650) mm was used to prepare the soil samples at the same initial water content and dry unit weight to show the effect of water content changes in different relations (swelling with time, swelling pressure with time, shear strength and soil suction). The results showed that the swelling potential decreases with increase in sand content from 14 to 2.4% by adding 50% sand to pure bentonite. The swelling percent found from the large-scale model is higher than that obtained from the oedometer swelling test for the same soil. This result applies well o...