The Effect of Suction on Shear Strength of Silty Clay

Abstract

The shear strength is one of the main mechanical performance indexes of soil, which is affected by many factors, such as the types of soil, the structure and the water saturation. The effect that soil water saturation exerts on shear strength is caused by the changing of the matric suction. As a result, It is important to research relationship between matric suction and the shear strength in engineering field. Therefore, the following study presented in this article takes silty clay as the object. In this paper, the matric suction and shear strength of soil under different saturation conditions are measured by pressure plate extractor and the triaxial compression apparatus, and the effect of matrix suction on the shear strength of silty clay is explored. Also, the functional relationship between the matric suction and shear strength of silty clay indicators that include cohesion and internal friction angle is obtained by the method of least square. Meanwhile, the formula of Coulomb is modified based on the above studies. The result shows that the cohesion of silty clay increases with the increase of matrix suction in the form of a power function, and the internal friction angle increases with the increase of matrix suction as a logarithmic function.