地震动输入能量衰减规律的研究

Attenuation of input energy of strong ground motion

对所收集到的266条强震记录,将其按场地条件分类,计算了不同场地条件、不同延性系数下的“绝对”和“相对”输入能量反应谱,然后利用两步回归法,得出了不同场地条件下地震动“绝对”和“相对”两种输入能量的衰减规律,分析了场地条件、延性系数、震级及距离等参数对地震动能量谱的影响,并对两种输入能量衰减规律进行了比较。

With 266 strong ground motion records from 15 significant earthquakes in the west of America, an attenuation relationship was developed for ground motion input energy spectra with earthquake magnitude, source-to-site distance, and site class. All the records are examined and classified into three site categories. For each horizontal component of one record, two different input energy equivalent velocity spectra, 'absolute' input energy equivalent velocity spectra and 'relative' input energy equivalent velocity spectra, are calculated for various ductility levels, and the geometric mean of the two horizontal components for each energy spectrum is used in a two-stage non-linear regression method. The effect of parameters such as magnitude, site class and ductility factor on the input energy spectra is discussed in the paper. It is found that both 'absolute' and ' relative' input energy are increased with the earthquake magnitude and attenuated quickly with the increasing of its distance.