中文摘要：

通过对20条远场类谐和地震动、20条近场类长周期地震动及10条普通地震动的弹性反应谱分析得出：长周期地震动与普通地震动在低频成分、加速度峰值、卓越周期几方面有较大差异。通过Hilbert-Huang变换理论中的经验模态分解,对典型的普通地震波与近远场长周期地震波进行分解后重组。分析比较重组后分量时程与原时程位移谱的拟合程度得出结论：长周期地震动重组后分量时程与原时程位移谱的相关系数大于0.8;普通地震动的重组后分量时程与原时程位移谱的相关系数小于0.8。由此提出一种定量区分长周期地震动与普通地震动的方法,为界定长周期地震动提供依据。

英文摘要：

According to analyze the elastic response near-field long-period ground motions and 10 ordinary spectrum of 20 far-field harmonic-like ground motions, 20 ground motions, the conclusion could be drawn that long-peri- od ground motions and ordinary ground motions have differences in the low frequency component, peak acceleration and predominant period. By the empirical mode decomposition of the Hilbert Huang transform theory, the research restructures rordinary ground motions and near-field and far-field long-period ground motions. After analyzing and comparing the displacement spectrum of restructuring seismic time-histories and the original seismic time-histories, it is concluded that the correlation coefficient of displacement spectrum of restructuring seismic time-histories and the original seismic time-histories of long-period ground motions is greater than 0.8; the correlation coefficient of displacement spectrum of restructuring seismic time-histories and the original seismic time-histories of ordinary ground motions is less than O. 8. Based on the above, the paper puts forward a quantitative way to distinguish be- tween long-period ground motions and ordinary ground motions, wich could provide the basis for defining the long- period ground motions.