关键词: 三维弹塑性细胞自动机, 岩石破裂过程, 非均质性, 围压, I类和II类曲线

Abstract:

The basic components of solid cellular automaton were defined in three-dimensional condition. The theories of elastoplasticity, cellular automaton, statistics and rock mechanics are integrated to develop an elastoplastic cellular automaton model to simulate the failure processes of heterogeneous rocks under three-dimensional condition and the associated numerical code EPCA3D was compiled in Visual C++ environment. The EPCA3D code was used to simulate the failure processes of heterogeneous rocks under uniaxial compression. The failure mechanism was well explained by analyzing failure pattern, inner failure position, complete stress-strain curves as well as the acoustic emission. It is found that the EPCA3D has the ability to simulate crack initiation, propagation and coalescence in the failure processes of rocks. Using the developed model, the effect of confinement on the complete stress-strain curves is investigated by using the linear combination of stress and strain loading control method. It is concluded that brittle heterogeneous rock is prone to behave Class II with small confinement and behave Class I with big confinement. The strength of the rock is lower with smaller confinement and vise versa, which is consistent with the results obtained from physical experiments.

Key words: 3D elastoplastic cellular automaton, rock failure process, heterogeneity, confinement, Class I and Class II curves