Wavelet-based Analysis for Pulse Period of Earthquake Ground-motions

Pulse period of earthquake records has been known as a key parameter in seismology and earthquake engineering. This paper presents a detailed characterization of this parameter for a special class of earthquake records called pulse-like ground motions. This type of motions often resulting from directivity effects is characterized by a strong pulse in the velocity time history of motion, in normal-fault component. Wavelet analysis was used as a powerful and useful technique in the analysis of non-stationary signals in this study. The period of velocity pulses is basically determined by using the pseudo-period of the mother wavelets. The effects of three different mother wavelets on results were investigated and new empirical predictive equations for pulse period have been derived.