Ranking of pulse-like ground motions

Abstract

Near-fault seismic ground motions are frequently characterized by intense velocity and displacement pulses of relatively long periods that clearly distinguish them from typical far-field ground motions. Intense velocity pulse motions can affect adversely the seismic performance of structures. In response to the realization of the importance of near-fault motions on structural performance, a number of studies have been directed to developing procedures for the identification of ground motions containing velocity pulses; these procedures classify ground motions as yes/no (pulse or non-pulse). The procedure proposed by Panella, Tornello, and Frau to identify pulse-like ground motions is based on the parameter called “development length of velocity time history”. It classifies ground motions in pulse or non-pulse too, but besides that, it is able to assess the level of impulsivity of them. In this work, we present a ranking of pulse-like ground motions based on the severity of the pulses. This paper may be a help to an adequate selection of records that are used to analyze structures in near-fault regions. The study ends with an analysis of the regions in the acceleration response spectra where they are affected for the velocity pulses.