论文部分内容阅读
运用三维有限单元法，探索地壳结构的非均匀性对地壳应力场的影响．假定分层地壳结构中镶嵌高速块体，低速块体，高、低速块体３种情况，分别计算壳内平均应力与水平剪应力的变化图像．结果表明：高速块体单独存在可导致高应力在高速体内的局部集中，并在其边缘和四个角区形成应力的高度集中，有利于强震的孕育和发生；低速体单独存在时，由于低速体本身不能积累应力，而其上部的应力集中程度不大，难以形成强震；高、低速体的同时存在则有利于高应力在高速体内的高度集中和在高速体外的地壳上、下部的相对集中，形成对大地震孕育、发生更加有利的条件．本文结果与邢台地震序列的空间分布图像吻合甚好．
Using the three-dimensional finite element method, the influence of crustal structural heterogeneity on the crustal stress field is explored. Assuming three kinds of cases, such as high-speed block, low-speed block, high-speed and low-speed block, are embedded in the layered crust structure, the change images of average stress and horizontal shear stress in the shell are respectively calculated. The results show that the existence of high-speed blocks alone can lead to the local concentration of high-stress in high-speed body and the high concentration of stress in the edge and the four corners of the block, which is beneficial to the gestation and occurrence of strong earthquakes. The low velocity body itself can not accumulate stress, but the upper part of the stress concentration is not large, it is difficult to form strong earthquakes; high and low speed body at the same time is conducive to high stress in high-speed body highly concentrated and high-speed in vitro crust, the lower Relatively concentrated, the formation of the earthquake, occurred more favorable conditions. The results are in good agreement with the spatial distribution of Xingtai earthquake sequence.