Quantitative classification of near-fault ground motions using wavelet analysis
Quantitative classification of near-fault ground motions using wavelet analysis
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DOI：
10.1785/0120060255
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发表时间：
2007-10-01
影响因子：
3
通讯作者：
Baker, Jack W.
中科院分区：
文献类型：
--
作者：
Baker, Jack W.
描述了一种定量识别包含强速度脉冲的地震动的方法，例如由近断层方向性引起的地震动。该方法利用小波分析从给定的地面运动中提取最大的速度脉冲。提取的脉冲相对于原始地面运动的大小被用来开发一个定量的标准，分类为“类脉冲地面运动。“该标准是通过使用人工分类的地面运动训练数据集进行校准的。为了确定这些脉冲记录的最大的工程利益的子集，两个额外的标准：脉冲到达早期的地面运动和速度脉冲的绝对振幅大。速度脉冲的周期（工程师感兴趣的量）是很容易确定的程序的一部分，使用伪周期的基础小波。这种分类方法对各种地震学和工程学主题都很有用，其中脉冲式地面运动是感兴趣的，如概率地震危险性分析，地面运动预测（“衰减”）模型，和结构的非线性动力分析。使用这种方法处理下一代衰减（NGA）项目的地面运动库，并发现91个大速度脉冲中的故障正常分量的约3500强地面运动记录考虑。据信，许多已识别的脉冲是由近断层方向性效应引起的。该程序可以作为一个独立的分类标准，或作为一个过滤器，以确定地面运动值得更仔细的研究。
A method is described for quantitatively identifying ground motions containing strong velocity pulses, such as those caused by near-fault directivity. The approach uses wavelet analysis to extract the largest velocity pulse from a given ground motion. The size of the extracted pulse relative to the original ground motion is used to develop a quantitative criterion for classifying a ground motion as "pulselike." The criterion is calibrated by using a training data set of manually classified ground motions. To identify the subset of these pulselike records of greatest engineering interest, two additional criteria are applied: the pulse arrives early in the ground motion and the absolute amplitude of the velocity pulse is large. The period of the velocity pulse (a quantity of interest to engineers) is easily determined as part of the procedure, using the pseudoperiods of the basis wavelets. This classification approach is useful for a variety of seismology and engineering topics where pulselike ground motions are of interest, such as probabilistic seismic hazard analysis, ground-motion prediction ("attenuation") models, and nonlinear dynamic analysis of structures. The Next Generation Attenuation (NGA) project ground motion library was processed using this approach, and 91 large-velocity pulses were found in the fault-normal components of the approximately 3500 strong ground motion recordings considered. It is believed that many of the identified pulses are caused by near-fault directivity effects. The procedure can be used as a stand-alone classification criterion or as a filter to identify ground motions deserving more careful study.