Decomposition and Effects of Pulse Components in Near-Field Ground Motions

Long-period pulse components in near-field ground motions have been known to cause significant damage to flexible structures. In this paper, an empirical mode decomposition (EMD) approach is used to identify and separate the dominant pulse, high-frequency, and long-period components in near-field ground motions. The pulses synthesized by an analytical pulse model recently proposed by the authors are compared to the extracted pulse components from recorded earthquake records using EMD, and the responses of linear and nonlinear structures subjected to these components are analyzed. The results demonstrate that (1) the characteristics and effects of the pulses generated by the analytical pulse model are similar to those of the extracted pulse components and (2) the pulse components are responsible for the peak responses of elastic structures subjected to near-field ground motions and govern the extent of inelastic structural damage in all frequency ranges.