Design Ground Motion for Lifeline System Taking into AccountFault Rupture Process

应用倒谱分析将地震波解卷积为系统响应函数和脉冲序列。基于几个标准，以尽量减少误差，我们提出了一种方法来识别源机构使用识别的脉冲串。为了检验所提出的反褶积方法的有效性，对模拟波进行了分析。利用埃尔森特罗台阵14个台站记录的地震加速度记录，对1979年加州Imperial Valley地震的断层机制进行了研究。通过选择合适的破裂过程中的故障参数值，使解卷积后的脉冲串与理论计算值之间的误差最小，可以估计破裂速度、破裂起点、破裂传播方向和上升时间。在断层面上识别出5个主要的小事件，证实了该断裂的多次破裂过程，识别出的地震矩在断层面上的分布与用不同方法研究的结果相吻合。解析算法导致非线性系统的反演和识别参数的不唯一性。为了克服这些问题，我们应用贝叶斯规则，它提供了一个定量的误差度量，考虑到先验信息的影响，用于识别参数。

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.