中国大陆及邻区强震活动主体地区形成的数值模拟

在一定时期内，中国大陆及邻区强震活动发生在相对集中的地区，本文简称为主体地区；不同时期的主体地区在空间上有较大距离的转移与变换．本文在前人研究基础上，对主体地区的形成机制进行探讨，认为岩石圈韧性层的变形控制了强震活动主体地区的主要位置和形态，而周围板块边界作用是形成主体地区的主要驱动力． 以中国大陆及邻区韧性层为模拟对象，建立二维粘弹性有限元模型模拟韧性层的变形及应力场分布．考虑到板块边界活动在时空上的不均匀性，将板块边界分段，以不同板块边界段组合作为各时期强震活动主体地区形成的主要约束，模拟大陆内部韧性层应力集中区的形成．模拟结果显示了6种与实际强震活动主体地区有可比性的应力分布，说明在相应的板块边界段组合作用下，在韧性层可以形成与各主体地区的形态和方位基本一致的应力集中区． 

THE FINITE ELEMENT MODELING OF STRONG EARTH-QUAKE MAJOR REGIONS IN CHINESE MAINLAND AND ITS VICINITY

The strong earthquakes in Chinese continent and its vicinity occure in certain regions during a time period, it is named as major regions for short in this paper. The major regions in different periods have a large scale migration. In this paper, we discuss the mechanism based on the former research. It is proposed that the the ductile layer of the lithosphere is the place where the major regions form, and the deformation of the ductile layer controls the locations and shapes of the major regions, and the effection from the plates around the researching area is the main driving force.A two dimensional visco elastic finite element model is formed to modeling the deformation field and stress field of the Chinese mainland and its vicinity. The boundaries of the model are divided into several segments to embody the non uniform of different boundaries. The stress concentration in the continental ductile layer constrained is simulated under various effects of different boundary segments. Six models in which the stress concentration areas are consistent with the real major regions are worked out. It is proved that, there could be formed the stress concentration areas in the ductile layer simulated with the real main regions under various effects of different boundary segments.