宏观非均匀性对岩石微震序列类型和破裂方式影响的数值试验研究

Numerical test of influence of macroscopic heterogeneity on seismic sequence types and mode of rock failure

运用岩石破裂过程分析RFPA2D系统,研究了岩石介质宏观非均匀性(含裂纹)对宏观力学行为和微震序列类型的影响。通过对5种不同岩石介质结构的宏观非均匀性样本进行破裂过程的数值模拟,发现非均匀程度不同会产生不同地震序列类型,主要有:前震-主震-余震型、主震型和震群型。此外,对5种不同均质度系数的岩石样本破裂过程的模拟。结果表明,岩石介质结构的宏观非均匀性不仅对岩样宏观强度和宏观变形非线性行为有显著的影响,而且也显著地影响试样破裂模式。随着非均匀程度的降低,主破裂呈现脆断模式,而随着非均匀程度的增加而呈现韧性破坏特征。

A numerical method, RFPA^2D used in analysis of rock failure process, is applied to study the influence of macroscopic heterogeneity on macroscopic mechanical behavior of rock failure and seismic sequence types. The failure processes of rock samples with 5 different kinds of macroscopic heterogeneity are simulated by numerical calculations. The resuits show that rock failure with different heterogeneities can produce different seismic sequence types, mainly including： foreshock-main shock-aftershock, main shock and swarm type. Besides, the numerical simulation of rock failure with 5 different kinds of heterogeneities shows that the macroscopic heterogeneities affected the non-linear behavior of rock deformation and macroscopic strength as will as failure mode obviously. With the decreasing of heterogeneity, the main failure process presents brittle behavior, and vice versa, with the increasing of heterogeneity, failure process presents ductile behavior.