Analysis of Shear Characteristics of Cohesive Soil and Rigid Base: A Case Study of Concrete Base

Taking the concrete as an example, this paper studies the shear characteristics of the cohesive soil and rigid base. A series of shear tests are conducted by the refitted DSJ-2 electric four-joint equal stress direct shear apparatus. The results in the shear tests are contrastively analyzed. The results show that under the condition of simple shear tests, the constitutive relation of structural interface between the clay and concrete is rigid, and the residual strength is obvious. Under the condition of direct shear tests, the shear stress-displacement curves present hyperbolic connection. There is obvious strain hardening phenomenon, no obvious peak strength and residual strength. Under the two experimental conditions, the peak shear strength of the interface increases with an increase in the normal stress. With increasing moisture content, the peak shear strength of the interface decreases. The internal friction angle and cohesion of the structural interface decrease with increasing moisture content, and the relationship between internal friction angle, cohesion of the structural interface and moisture content are nonlinear. The peak shear strength of the direct shear tests is greater than that of the simple shear tests.