TEST STUDY ON SHEAR STRENGTH OF UNSATURATED SOILS

In order to verify the suction constitution in unsaturated soils, some un-hygroscopic tests are designed and performed.The testes are classified into four different types including common triaxial tests, pressure plate common triaxial tests, pressure plate GDS triaxial tests and natural air drying common triaxial tests.The results indicate that the friction angle related to unsaturation can be greater than that induced by net normal stress in a higher saturation state and the strength increment induced by unsaturation is linear to matric suction in a lower saturation state.Failure occurs distinctly in a slope for unsaturated soil samples but this is not true for the saturated one.