ABSTRACT
Unsaturated soil regions with high soil suctions are generally located near ground surface. This study reports the results of triaxial tests on a silty soil. The modified triaxial cell apparatus applied a constant net normal stress and varying soil suctions as well as having a constant high total suction with the net normal stress varying. Matric suctions were applied to soil specimens in the triaxial cell, through a ceramic base plate for suctions up to 450 kPa. Higher total suctions were applied to soil specimens in a glass desiccator where salt solutions were used to create a constant relative humidity chamber. Total suction values up to 292,400kPa were used in this test program. This study showed that the failure envelope with respect to suction was composed of two segments; namely, a curvilinear segment at low suctions and a horizontal segment at high suctions.
