A Simple and Quantitative Algorithm for Identifying Pulse-Like Ground Motions Based on Zero Velocity Point Method

Pulse-like ground motions, which are mainly concentrated in near-fault regions, can induce severe damage on structures. This article presents a simple and effective method used for quantitatively identifying pulse-like ground motions. First, zero velocity point method is proposed based on the properties of trigonometric functions. This method can reveal the time-domain characteristics of ground-motion velocity time history and can be used to detect the potential velocity pulse which is included in corresponding original ground motion. Second, pulse-like ground motions are classified into two classes: single-pulse-like and multi-pulse-like ground motions. Further, single-pulse-like is divided into significant-single-pulse-like and non-significant-single-pulse-like, while multi-pulse-like is divided into double-pulse-like, three-pulse-like, and four-pulse-like. Third, energy method is adopted to formulate the identification criterion for each type of pulse-like ground motion. Finally, the energy parameters of the detected potential velocity pulse for a large number of ground motions are calculated, and the proposed identification criteria are applied to identify whether these ground motions are pulse-like or not. A comparison of the methodology proposed in this study with previous identification methods is presented. Analysis results indicate that the methodology proposed in this study can accurately distinguish pulse-like and non-pulse-like ground motions.