断层结构非均匀性对地震活动性影响的细胞自动机模拟

基于断层强度分布的非均匀性,构建了由81×81个细胞单元组成的4种不同匀质度及其各自6种不同随机构型共计24个非均匀二维单断层模型样本,并通过设计的细胞自动机模拟程序,在保持其它模拟参数不变的条件下对它们进行了模拟试验.研究结果表明,随着断层结构非匀质度的增加,其宏观变形破坏行为由相对脆性向塑性变化；地震序列类型依次表...

Simulation of effect of fault structure heterogeneity on seismicity using cellular automata model

A 2-D cellular automata fault model with 81×81 cells was constructed to test its seismicity performance. In a series of tests 4 kinds of fault strength heterogeneity and 6 different strength geometrical distributions were taken. With the model simulation we analyzed how the fault structure heterogeneity affects macroscopic fault failure behavior and generated seismic sequence type. The results show that with increasing degree of heterogeneity the macroscopic deformation and fracture process present from brittle to plastic behavior, and produce 3 different types of seismic sequence, i.e., main shock type, foreshock-main shock-aftershock type and swarm type. In the same time, with increasing fault strength heterogeneity the fracture size distribution more regularly follows the G-R relation. Besides, temporarily the events occur in a certain random process, that is, small events appear randomly, medium size events occur in clusters and large ones emerge quasi-periodically. The event clustering and quasi-periodic occurrences become less significant with the fault heterogeneity increasing. It is also found that the randomness of structural geometric variation may affect characteristics of seismic sequences, but the difference in randomness becomes weaker as degree of heterogeneity increases.