作　　者： ; ; ; ; ;

机构地区： 东北大学

出　　处： 《地球物理学报》 2003年第5期659-666,共8页

摘　　要： 运用岩石破裂过程分析RFPA2D系统 ,研究了岩石介质细观非均匀性对宏观力学行为的影响和微震序列特征 .通过对不同均质度系数m =1.1,1.5 ,2 ,3,5的 5个样本进行破裂过程的模拟 ,发现均质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表明 ,岩石介质的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 .随着均质度系数的提高 ,主破裂呈现脆断模式 .同时介质的细观结构随机性 ,也对试样宏观破裂模式产生重要影响 . 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.

关 键 词： 岩石破裂过程分析 非均匀性 微震序列类型 变形局部化 数值试验

领　　域： [天文地球] [天文地球]