【摘要】 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.更多还原

【Abstract】 For studying the geomechanical process of the development and occurrence of shallow tectonic earthquakes, this paper proposes a model for the earthquake fault before the shock, consisting of three stages: the first -- stress accumulates in the relatively stable locked zone; the second--the slipping zone extends and the locked zonecontracts in which high concentration of stress takes place; the third-- residuallocked zone contracts to a certain degree causing violent displacement of the fault.Based on this variation of mechanical state at the earthquake fault, the additional stress given rise on its surroundings and the stress change of this process have been computed and analyzed. The results show that this model agrees with observations and experiences in practice and that it explains certain observed facts before the 1975 Haicheng earthquake.更多还原