断层间相互作用的触震与缓震效应定量评价

Interaction of Active Faults and Its Effect on Earthquake Triggering and Delaying

本文提出了同震库仑应力改变的基本概念 ,应用Navier Coulomb破裂准则 ,探讨了其求解方法 ,从同震库仑应力改变思想出发 ,结合活动断层地震危险性概率预测方法 ,分析了断层间相互作用导致的触震与缓震效应及其定量表达方法 ,并以鲜水河断裂带为例进行了应用研究 ,检验和评价了断层间相互作用触震与缓震效应的重要性。

The concept of Coseismic Coulomb stress change is proposed, and the method for its calculation is briefly discussed by using Navier-Coulomb criteria. From the viewpoint of Coseismic Coulomb stress change and according to the probabilistic method for predicting active fault seismic potential, the triggering and delaying effects of fault interaction as well as the method for its description are analyzed. As an example, the Coseismic Coulomb stress changes caused by active faults interaction in the famous Xianshuihe fault belt of southwest China are calculated and their influences on seismic potential are quantificationally assessed and discussed. It is concluded that an earthquake not only releases stress on the seismogenic fault, but also causes Coseismic Coulomb stress changes on its surroun-ding faults,which can trigger or delay the next earthquake. The recurrence probability changes caused by active faults interaction can be up to 30.5%, so the interaction of active faults must be considered in seismic potential assessment and prediction.