采用HHT方法分析近场及远场长周期地震动的特点

Analysis of Characteristics of Near-field and Far-field Long-period Ground Motions Using HHT Method

利用HHT方法非线性信号时频分析原理,研究近场和远场地震动频率变异系数和能量变化规律,表明带有速度脉冲的近场长周期地震动的频率和能量特征具有明显突变性,频率变异系数较大,而远场长周期地震动频率和能量变化相对平稳,频率变异系数较小。

Using the principle of time-frequency analysis of nonlinear signals with the HHT method,the frequency variation coefficients and energy variation laws of near-field and far-field vibrations are studied,indicating that the frequency and energy characteristics of near-field long-period ground motions with velocity pulses have obvious mutations.The frequency variation coefficient is large,while the long-period ground motion frequency and energy change are relatively stable,and the frequency variation coefficient is small.