Numerical Simulation On Failure Process Of Rock Subjected To Stress Wave

The rock dynamics problems, such as rock under impulsive loading, widely exist in a variety of engineering applications including rock failure, hydraulic fracturing, and rock blasting, earthquake prediction, slope stability and rock burst. The rock blasting mechanism, propagation of stress wave and dynamic fracture of rock are focus of rock mechanics for mining engineering. Therefore, it is of significance to study the fracture process of rock subjected to stress waves.Numerical code RFPA-Dynamic is used to study the propagation of stress wave and the failure process of rock under dynamic loading. This thesis deals with the following issues:(1) The failure processes of homogeneous rock and heterogeneous bars subjected to dynamic loading are simulated in order to study the stress wave propagation in the rock. The numerical simulation reproduces the failure process of the rock bar, indicating that the heterogeneity of rock have a significant effect on the propagation of stress wave and rock failure process.(2) The failure processes as well as the patterns, which are dominated by the amplitudes and wavelength of the incident stress waves, are studied. Numerical results denoted that the dynamic failure processes are controlled by three factors: i.e. tensile strength of rock, amplitudes of stress waves and waveforms of stress waves. A variety of failure patterns are found and several typical failure mechanisms are clarified for rock specimens under different amplitudes or durations of incident compressive stress waves. All these failure patterns of rock specimens under dynamic loading are different from the failure pattern under static loading.(3) The failure processes of tunnel under dynamic full-width normal stress and local-width normal stress are simulated. The different failure patterns are found and different failure mechanisms are clarified for tunnels when they are compared the ones under static loading conditions.