An improved energy‐based approach for selecting pulse‐like ground motions

Abstract

Summary This study proposes an improved energy‐based approach for quantitative classification of velocity‐pulse‐like ground motions. The pulse amplitude is determined, in its value and in time location, by the amplitude of the half‐cycle pulse having the largest seismic energy. After conducting statistical analyses, a newly‐determined threshold level for selecting pulse‐like ground motions is derived; and then what followed is a comparison analysis of three pulse‐detecting schemes, one using the wavelet analysis, the other two using the energy concept. It is believed that other than providing a useful way of classifying pulse‐like ground motions for structural demand analysis, knowledge of this work could also benefit the development of the ground motion prediction equations accounting for pulse effects, and further to aid the probabilistic seismic hazard analysis in a near‐fault environment. Copyright © 2016 John Wiley & Sons, Ltd.

Automated classification of near‐fault acceleration pulses using wavelet packets

“…Comparison of the T p calculated in the current study with those derived by (a) Chang et al. (), (b) Baker (), (c) S v , and (d) S d⋅ S v …”

“…This way of using WPT for deriving T p is then compared with those in Baker (), Chang et al. (), the S v , as well as S d ⋅ S v methods. In Figure , the comparative results are shown in terms of scatter plots, reporting the correlation coefficients (ρ) between the T p estimates based on the different studies.…”

“…The scatter points represent the formerly used 129 components that were all identified as pulse‐like by three different methods in Chang et al. (). It can be seen that overall the five methods of calculating T p have comparable outcomes, with the current T p values having the largest correlation coefficient with those of Baker's algorithm.…”

“…() and Chang et al. () is the efficient extraction of velocity‐pulses with peculiar shapes. Subsequently, the peak point method (PPM) is used to determine the velocity‐pulse‐starting ( t s ) and pulse‐ending ( t e ) time instants, which are then taken to cut off the acceleration time‐history.…”

Near‐fault acceleration pulses and non‐acceleration pulses: Effects on the inelastic displacement ratio

“…Specifically, the seismic damage within a near-fault region is often caused during a few cycles of severe inelastic deformation that coincides with large amplitude velocity pulses in the ground motions. [11][12][13] From the engineering perspective, the effects of pulse-like ground motions on various structures have been investigated, including idealized single (or multi)-degree-of-freedom (SDOF) systems, 14,15 seismically base-isolated structures, 16,17 bridge structures, 18,19 and some other special buildings or elements. 2 Previous studies confirmed that key features of the velocity pulse, eg, amplitude, predominant period, and the pulse shape, play important roles in affecting the structural response and are primarily affected by the earthquake source characteristics, location of the recording station relative to the fault rupture as well as the site effects.…”