逆冲断层地震主震的突变理论分析  

Analysis of Main Shock of Thrust Fault Earthquake by Catastrophe Theory

作　　者：潘岳[1] 赵志刚[2] 

机构地区：[1]青岛理工大学土木工程学院,山东青岛266520 [2]山东科技大学矿业灾害预防与控制重点实验室,山东青岛266510

出　　处：《应用数学和力学》2012年第7期796-811,共16页Applied Mathematics and Mechanics

基　　金：国家自然科学基金资助项目(5067059)

摘　　要：逆冲断层系统作准静态形变时的功、能量增量关系可以分解为关于体积应变能的功能增量关系和关于偏应力能的功能增量关系.采用突变理论方法对逆冲断层系统的偏应力功能量增量关系进行的分析表明:折迭突变模型展示的性状可对逆冲断层地震主震的发震条件、演化过程和若干震后特性作恰当描述.围岩的围压大,最大主应力大,逆冲潜断层面倾角小,围岩切向刚度与断层抗剪强度曲线软化段拐点处斜率的比值小,则震时围岩弹性能释放量大、震级高,断层破裂半错距大,围岩端面位移振幅也大.断层岩体破裂扩容和震时围岩体积应变能释放,增强了前述效应.The relationship between work and energy increment of thrust fault system with qua- si-static deformation can be decomposed into two parts, i.e. the relationship between work and energy increment of volume strain energy and that of deviation stress energy, which was analyzed by using method of catastrophe theory. The research indicates that the characteristics displayed by fold catastrophe model can appropriately describe the earthquake generation condi- tion, the evolvement process of main shock of thrust fault earthquake and some important earthquake effects as well. The bigger the surrounding press of surrounding rock is, the bigger the maximum principal stress is. The smaller the incidences of the potential thrust fault surface are, the smaller the rate between the tangential stiffness of surrounding rock and the slope is, which is at inflexion point on the softened zone of fault shearing strength curve. Thus when earthquake occurrs, the larger the elastic energy releasing amount of surrounding rock is, i. e. the larger the intensity of earthquake is. The larger the half distance of fault dislocation is. The larger the displacement amplitude of surrounding rock end face is. Fracturing, expanding of the fault rock body and releasing of volume strain energy of surrounding rock while earthquake oc- cuffs enhance the foregoing earthquake effects togetber.

关 键 词：逆冲断层 地震 折迭突变模型 弹性能释放量 断层错距 

分 类 号：P315.3[天文地球—地震学]