Study on Attenuation of Ground Motion Input Energy Spectra

摘要

The seismic safety evaluation based on input energy may prove useful for the identification of scenario earthquakes because input energy is a convenient single-parameter descriptor of ground motion duration and amplitude. Based on 266 records, an attenuation relationship was established for two kinds of both elastic and inelastic input energy spectra with earthquake magnitude, source-to-site distance, and site class. The results show that the site class has a significant effect on both absolute and relative input energy spectra. The two kinds of input energy spectra increase rapidly with the increasing of earthquake magnitude and attenuate quickly with the increasing of distance. Furthermore, the two kinds of input energy spectra increase with the increasing of ductility factor in short period range and decrease with the increasing of ductility factor in long period range. The effect of ductility on the relative energy spectra in short period range is much larger than that on the absolute energy spectra but very similar in long period range. After comparison of two kinds of input energy spectra constructed from the attenuation relationship, it is found that the absolute input energy spectra are some larger than relative input energy spectra in short period range and some less than relative input energy spectra in long period range, and they are almost equivalent at the period about 0.5s. The input energy demand of structures in future earthquake can be evaluated according to the results of the paper.