Interfacial Shear Properties of Red Clay and Polyurethane with Different Densities

Polyurethane reinforced slopes have been widely used in practical engineering, for the stability of the composite structure, the interfacial shear performance between polyurethane and soil plays a crucial role. This paper through the indoor interfacial shear test, study the relationship between shear displacement and shear stress at the polyurethane-red clay interface under the different polyurethane densities. At the same time, based on the bilinear finite element cohesive model, using ABAQUS finite element software to establish a numerical model of polyurethane-red clay composite specimens to simulate the indoor shear test process, and to study the shear stress and shear strength changes at the interface between polyurethane and red clay; verify the feasibility of the numerical model by comparative analysis. The test results show: The incorporation of polyurethane has a significant promoting effect on the interfacial shear strength, there is a linear positive correlation between the interfacial shear strength and the density of polyurethane; The shear strengths of the composites with densities of 0.2 g/cm3, 0.5 g/cm3, and 0.8 g/cm3 are 1.53 times, 1.60 times, and 2.24 times that of pure red clay respectively, the optimal polyurethane density is between 0.5 g/cm3–0.8 g/cm3; The bilinear finite element model can effectively simulate indoor shear tests, and the average error of the simulated shear strength result is within 9.4%, which provides an effective method for understanding the interfacial shear performance of the composite body.