Design Ground Motion for Lifeline System Taking into AccountFault Rupture Process

倒谱分析用于将地震波反卷积成系统响应函数和脉冲序列。基于几个最小化误差的准则，我们提出了一种利用已识别的脉冲序列来识别源机制的方法。为了验证所提出的反卷积方法的有效性，对模拟波进行了分析。结果表明，脉冲的到达时间在两个采样间隔的误差范围内估计，脉冲强度与脉冲的准确到达时间与估计到达时间之差成正比。在埃尔森特罗阵列的14个站点记录的加速度被用来确定1979年加利福尼亚帝国谷地震的断层机制。在破裂过程中选取合适的故障参数值，使反卷积脉冲序列与理论计算脉冲序列的误差最小，从而估计出破裂速度、破裂起点、破裂传播方向和上升时间。在断层表面发现了5个主要的小事件，证实了多次破裂过程。地震矩在断层表面的识别分布与其他方法的结果比较好。解析算法导致了系统的非线性反演和辨识参数的非唯一性。为了克服这些问题，我们应用贝叶斯规则，该规则提供了一个定量的误差度量，考虑了先验信息对参数识别的影响。

The cepstrum analysis was applied to deconvolute a seismec wave into a system response function and a train of impulses. Based on several criteria to minimize error, we propose a method to identify the source mechanism using identified trains of impulses. Simulated waves were anakyzed in order to examine the validity of the proposd decomvolution method. It was found that arrival time of an impulse was estimated within teh error of two sampling intervals and intensity of impulse was proportional to the difference between the exact and estimated arrival time of the impulse.The accelerograms recorded at fourteen stations in El Centro Array are used to identify the fault mechanism of the 1979 Imperial Valley, California earthquake. The rupture velocity, the starting point of rupture, the direction of the rupture propagation and the rise tiome can be estimated by minimizing the error between deconvoluted trains of impulses and theoretically calculated ones by selecting proper values of fault parameters in the rupture process. The multiple rupture process was confirmed by the fact that five major small events were identified on the fault surface.The identifide distribution of seismic moment on the fault surface compares well with that investigated from different approach. The analytical algorithm led to the nonlinear system inversion and non-uniqueness of identified parameters. To overcome these problems, we applied Bayes' rule which provided a quantitative error measure taking into account the effect of prior informartion for identfying parameters.