Abstract:How to realize the parameterization of velocity pulse and analyze the characteristics of parameters is a problem worthy of further study. In this paper, 126 groups of near-fault pulse-like ground motion records were selected from the NGA-West2 database. The velocity pulse model was used to obtain the characteristic parameters of horizontal component based on the least square method. The effects of magnitude, fault distance, and site type on the pulse parameters were studied, and the characteristics of the pulse parameters of fault-normal component and fault-parallel component were compared. The results showed that the change rate of peak pulse value of fault-normal component with magnitude and fault distance is faster than that of fault-parallel component, and the site conditions have a great influence on the variation of peak pulse with magnitude and fault distance. There is a strong linear correlation between the half pulse period and the main pulse period, and the variation of them with the magnitude is different. With the same magnitude, the pulse peak moment in bedrock site is smaller than that in soil site. For the Chi-Chi earthquake, the small shape parameters are mainly concentrated near the rupture fault. With the increase of fault distance, the difference of pulse shape parameters between different components also increases.
