NUMERICAL TEST OF INFLUENCE OF MESOSCOPIC HETEROGENEITY ON MACROSCOPIC BEHAVIOR OF ROCK FAILURE AND SEISMIC SEQUENCE TYPES
细观非均匀性对岩石破裂过程和微震序列类型影响的数值试验研究

A newly-developed numerical method, RFPA 2D , used for analysis of rock failure process, is applied to study the influence of mesoscopic heterogeneity on macroscopic behavior of rock failure and seismic sequence types. The failure processes of rock samples with 5 different kinds of heterogeneity are simulated by numerical calculations. The results show that rock failure with different heterogeneities can produce different seismic sequence types, mainly including (1) main shock-aftershock type, (2) foreshock-main shock-aftershock type, and (3)swarm type. Besides, the numerical simulation of rock failure with different heterogeneities shows that the non-linear behavior of rock deformation and fracture pattern as well as failure mode are obviously affected by the heterogeneities. With increasing the degree of rock homogeneity, the macroscopic failure process presents brittle behavior markedly. Meanwhile, it is also found that the failure modes of specimens are sensitive to the local variations of the mechanical properties of specimens with the same mechanical properties including the heterogeneity.