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为了探讨浅源构造地震孕育和发生的力学过程,本文提出了一种力学模式,其中把发震断层的震前状态划分为几个阶段,即相对稳定的闭锁区内应力积累—滑动区逐渐扩展、闭锁区收缩并造成闭锁应力高度集中—剩余闭锁区缩小至一定程度而导致断层剧烈错动的几个阶段.计算并分析了震源力学状态这种变化在其周围产生的附加应力场,以及反映这一过程的地应力变化特征.其结论与多年来地应力观测实践中取得的某些经验性认识相符,并较好地解释了1975年海城地震前的若干实测资料.
In order to study the mechanical process of the geologic inception and occurrence of shallow source tectonics, a mechanical model is proposed in this paper, in which the pre-earthquake state of the seismogenic fault is divided into several phases, that is, the relatively stable accumulation of stress in the closed area - , The closure zone shrinks and causes a high concentration of latching stress - the remaining closure zone shrinks to a certain extent and leads to the fault dislocation in several phases.An additional stress field around the change of source mechanical state is calculated and analyzed, This process is characterized by the variation of the geostress, and its conclusion is consistent with some empirical findings obtained from the practice of geostress observation over the years and provides a good explanation of some measured data before the Haicheng earthquake in 1975.