Mechanical behaviour of an unsaturated clayey sand

This paper presents the mechanical behaviour of an unsaturated clayey sand. 12 triaxial compression tests were performed on a sand-kaolinite mixture, including 3 saturated drained (CD), 3 saturated undrained (CU) and 6 unsaturated constant water content (CW) triaxial tests. Unsaturated constant water content tests were carried out with a double-walled triaxial cell and using the axis translation technique. The soil samples were remolded and brought to initial matrix suctions of 100 and 150 kPa. The soil specimens were consolidated and sheared under different values of net confining stress. Based on the results, the stress-strain and critical state behaviour of the soil are shown in terms of net stresses and suction. The water retention behaviour is presented as a surface relating degree of saturation to suction and specific volume.