【摘要】 地震断层破裂在周围固体介质中能产生静态附加应力场.当依据库仑破裂准则和破裂模型推测构造应力变化,用以判断能否触发某处断层破裂时,这种应力变化称作"库仑破裂应力变化".一次地震产生的"库仑应力变化"被认为能影响下一次地震的发生.讨论了计算"库仑应力变化"所采用的不同模型,指出伏尔泰拉错动模型不能真实反映震源参数,因而所给出的静态附加应力场存在重大缺陷.线弹性断裂力学模型可以与真实应力降联系起来,但不能给出震源参数的约束范围,也存在破裂端部应力奇异性问题.用滑动弱化模式不仅可以消除应力奇异性,而且可以对震源参数给出较合理的约束条件.理论分析表明,计算库仑破裂应力变化必须考虑到模型选择的合理性.另外,无论是哪种模式,利用固体格架破裂计算大地震的库仑应力变化在远场的量值都很低,在一般情况下似乎不足以影响下一次远场地震的发生,迄今为止的岩石试验和实际观测资料也尚不支持这个假说.鉴于全球的地震活动有远场相互关联和呼应,对大地震的远场静态触发作用的解释需要找出其它途径.更多还原

【Abstract】 Seismic fault failure can generate additional static stress in surrounding solid medium.The stress change,calculated by using certain fault model and following Coulomb fracture criteria,with the aim at testing if it can trigger other fault failures,is called Coulomb failure stress(CFS)change.It is commonly believed that the CFS change generated by an earthquake can affect the occurrence of other remote earthquakes.This paper examines and compares the calculations of CFS change in using three different models.Since the Volterra dislocation model can not accurately represent the source parameters,the additional static stress field given by this model has major flaws.The linear elastic fracture mechanics model can be related to the real stress drop,but can not give the limit range of the source parameters.In addition,it also has the problem of stress singularity at crack ends.The slip-weakening model not only eliminates the stress singularity,but also gives more reasonable constraints on source parameters.However,quantitative analysis shows that in calculating CFS changes the rationality of the fault model must be taken into account,and that for any above model the calculated CFS change induced by a major earthquake in far-field is very low,being not enough to influence the occurrence of another remote earthquake.Up to now rock experiments and actual observations do not support the hypothesis that the Coulomb stress generated by an earthquake can affect the occurrence of a next remote earthquake.Therefore,we need to find new ways to interpret the remote correlation of seismic activities around the world and the cause of static remote triggering of major earthquakes.更多还原