Abstract:The dynamic characteristics of undisturbed red clay in Guiyang under cyclic loading were tested by a SDT-20 dynamic triaxial testing machine in the laboratory. Effects of confining pressure, consolidation stress ratio, and vibration frequency on the dynamic parameters of red clay were investigated. Results showed that the dynamic constitutive relationship of Guiyang red clay conforms to the H-D hyperbolic growth model. Dynamic elastic modulus decreases nonlinearly with increasing dynamic strain, and the damping ratio increases nonlinearly with increasing dynamic strain. In addition, confining pressure and consolidation stress have a significant influence on the dynamic parameters of red clay. Details are as follows:with increasing confining pressure and consolidation stress ratio, dynamic deformation and damping ratio decrease, and dynamic elastic modulus increases. Under the same conditions, if the vibration frequency is increased, the kinetic parameters will follow the same law as confining pressure and consolidation stress ratio, though not significantly. Based on the H-D model, the hyperbolic model parameters of undisturbed red clay in Guiyang are given. The empirical model of dynamic elastic modulus attenuation and damping ratio of Guiyang red clay under different test conditions is proposed by multiple regression analysis, and the corresponding fitting parameters are given.
