Abstract:Dynamic triaxial test of Huashan granite was conducted to analyze the relationship between the strain rate and the granite compressive strength, the elastic modulus and Poisson’s ratio with different confining pressures. Test results show that with the same confining pressure, the compressive strength increases with the strain rate, but there are no apparent changes in the elastic modulus and the Poisson’s ratio of the granite. The compressive strength also becomes larger with increasing confining pressure at the same strain rate, while the elastic modulus and Poisson’s ratio changes little. Based on the above test results, Mohr Coulomb and Hoek Brown criteria were adopted to quantitatively analyze the relationship among compressive strength, strain rate and confining pressure. As for the former, the change of strength is primarily due to the variation of cohesion with strain rate. Assessment of the Hoek Brown criterion indicates that the uniaxial compressive strength increases with strain rate, but the parameter m changes very little.
