Identification of acceleration pulses in near-fault ground motion using the EMD method
In this paper, response spectral characteristics of one-, two-, and three-lobe sinusoidal acceleration pulses are investigated, and some of their basic properties are derived. Furthermore, the empirical mode decomposition (EMD) method is utilized as an adaptive filter to decompose the near-fault pulse-like ground motions, which were recorded during the September 20, 1999, Chi-Chi earthquake. These ground motions contain distinct velocity pulses, and were decomposed into high-frequency (HF) and low-frequency (LF) components, from which the corresponding HF acceleration pulse (if existing)and LF acceleration pulse could be easily identified and detected. Finally, the identified acceleration pulses are modeled by simplified sinusoidal approximations, whose dynamic behaviors are compared to those of the original acceleration pulses as well as to those of the original HF and LF acceleration components in the context of elastic response spectra. It was demonstrated that it is just the acceleration pulses contained in the near-fault pulse-like ground motion that fundamentally dominate the special impulsive dynamic behaviors of such motion in an engineering sense. The motion thus has a greater potential to cause severe damage than the far-field ground motions, i.e. they impose high base shear demands on engineering structures as well as placing very high deformation demands on long-period structures.
作 者： Zhang Yushan Hu Yuxian Zhao Fengxin Liang Jianwen Yang Caihong 作者单位： Zhang Yushan,Liang Jianwen,Yang Caihong(Department of Civil Engineering, Tianjin University, Tianjin 300072, China)Hu Yuxian,Zhao Fengxin(Institute of Geophysics, China Earthquake Administration, Beijing 100081, China)
刊 名： 地震工程与工程振动（英文版） SCI 英文刊名： EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION 年，卷(期)： 2005 4(2) 分类号： P315 关键词： acceleration pulse velocity pulse near-fault pulse-like ground motion empirical mode decomposition(EMD) response spectrum