The Experimental Study of the Influence of the Matric Suction on the Unsaturated Soil Strength

With modified unsaturated soil triaxial apparatus, unsaturated soil shear strength of the tests under the condition of different water contents are done. Experimental results show that the matric suction exist in unsaturated soil and increases with the decrease of moisture content. And the shear strength of unsaturated soil is higher than that of saturated soil. Shear strength of unsaturated soil varies as the matric suction and water content. The shear strength increases when the matric suction increases. when soil tend to be saturated, the matric suction will tend to be zero. And the shear strength of unsaturated soil values gradually close to the strength of the saturated soil.

Triaxial Shrinkages Tests of Unsaturated Compacted Clay

In this paper, The GDS unsaturated soil triaxial apparatus are employed for experimental tests to obtain the main characteristics of the drying paths for compacted clay. In order to study the soil water characteristic curve and shrinkage coefficient under deferent net mean stress. The results show that shrinkage index and the soil-water characteristic curve are dependent on net mean stress. At a given matric suction, with the increase of net mean stress, the void ratio and water content of soil sample is decrease, but the degree of saturation is increased.