【摘要】 本文依据基于地震学理论合成地震动的随机方法和能够细致描述震源复杂性的有限断层模型,采用随机有限断层法直接生成最大可信地震。重点比较了随机有限断层法的静拐角频率和动拐角频率理论,开发基于静拐角频率方法的Fortran程序SFFMSIM,作为对比,引进了动拐角频率程序EXSIM。选用1994年Northridge地震数据检验本文采用的随机有限断层模拟方法和程序。最后以大岗山水电站工程为例,采用随机有限断层法生成磨西断裂发震时工程场址可能产生的最大可信地震的加速度时程曲线。结果显示:随机有限断层法合成时程的放大系数谱均值与80条基岩记录平均谱的一致性较好。预测震源位错分布形式未知的地震时,动拐角频率和静拐角频率方法的模拟结果有差异。更多还原

【Abstract】 On account of the stochastic method of ground motion simulation based on seismology theory and the finite fault source model which can describe the complexity of the earthquake source accurately,the stochastic finite fault method is applied directly to generate the maximum credible earthquake.Two theories of the stochastic finite fault method,including the static corner frequency theory and dynamic corner frequency theory,are compared.According to the static corner frequency theory,a Fortran program SFFMSIM is developed,while EXSIM,a program based on the dynamic corner frequency theory,is introduced for comparison.The stochastic finite fault method and procedures of simulating ground motions used in this paper are validated against strong motion data of 1994 Northridge earthquake.Finally,taking the Dagangshan hydropower for example,the artificial accelerograms of the maximum credible earthquake generated from the rupture of Moxi fault and recorded at the dam site are simulated by the stochastic finite fault method.The results show that the average values of the strong-motion amplification factors produced by the stochastic finite fault method and those derived from 80 real rock accelerograms are in good agreement.There are some differences between strong motions simulated by the static corner frequency method and dynamic corner frequency method when the slip distribution on the causative fault is unknown.更多还原