基于非因果滤波和零点法的近断层脉冲型地震动识别方法

Near-fault pulse-like ground motion identification method based on non-causal filtering and zero-point method

基于Butterworth非因果低通滤波器和零点法提取地震动速度时程中的脉冲信号,并以脉冲信号中的极值点数量确定滤波器的截止频率。选取666条速度峰值大于30 cm/s的近断层地震记录作为训练数据,以脉冲信号的相对能量和幅值作为量化指标,给出了单脉冲型和双脉冲型地震动的识别标准;提出了以最显著脉冲信号的持续时间为依据的脉冲周期计算方法。通过与既有方法比较表明:基于Butterworth非因果低通滤波器和零点法的脉冲提取方法的拟合效果较好,可用于提取非对称脉冲信号和双脉冲信号;提出的定量识别标准可以有效地识别单脉冲型和双脉冲型地震动;所提的脉冲周期计算方法可以用于确定单脉冲型和双脉冲型地震动的脉冲周期。

Here,based on Butterworth non-causal low-pass filter and the zero-point method,pulse signals in time history of ground motion velocity were extracted,and the cut-off frequency of the filter was determined with the number of extreme value points in pulse signals.666 near-fault seismic records with their peak velocities larger than 30 cm/s were selected as training data,and the relative energy and amplitude of pulse signals were taken as quantitative indexes to give identification standards of single-pulse and double-pulse ground motions.A pulse period calculation method according to the duration of the most significant pulse signal was also proposed.Comparing the proposed method with the existing methods showed that the pulse extraction method based on Butterworth non-causal low-pass filter and the zero-point method has a better fitting effect,and can be used to extract asymmetric pulse signals and double-pulse signals;the proposed quantitative identification standards can effectively identify single-pulse and double-pulse ground motions;the proposed pulse period calculation method can be used to determine pulse periods of single-pulse and double-pulse ground motions.