Assessment of Shear Strength Characteristic for Unsaturated Kaolin Clay in Qaime, Iraq

In fact, the unsaturated soil testAis not common in soil mechanics labs, and the unsaturated soils are feature higher strength and stiffness than saturated soil. The study focuses on the preparation of samples (kaolin from Qaime city), it uses the static compaction (one dimension) to keep on the samples initial water content, specific volume and degree of saturated constant. During the wet state, all samples appeared to have increasing water content, specific volume and degree of saturated by log time, and matric suction value was constant, during the equalization state this value was constant after about 40 hr., isotropic load was constant value (600) kPa and applied on a sample in each direction, during shearing loading for all case, the matric suction was constant value S (30, 60 and 90) kPa during testing. In this paper, the results of wetting stages showed the deviatoric stress increases with the increase in matric suction value. The axial and volumetric strain recorded the low value at S90 kPa because of the increasing matric suction value.