【摘要】 依据171次地震中3 462组三分量地震记录,对竖向地震动的一些特性进行了统计分析,结果表明:(1)在近场区,竖向地震动的影响较大,峰值较大而且往往首先出现;(2)地面震动强度越大,竖向地震动的相对比值V/H1越大;(3)V/H1峰值比的总体平均值约为0.5,V/H1≤0.65的总体累积概率约为84.5%;(4)竖向反应谱曲线下降段的衰减指数小于水平向;竖向反应谱拐点周期要小于水平反应谱,而且与场地条件关系不大。更多还原

【Abstract】 Based on 3 462 records of three-component seismograms from 171 earthquakes,the characteristics of vertical seismic ground motions were analyzed. The results show that:( 1) in near-field,the peak ground accelerations( PGA) of vertical components are often larger than that of horizontal components,and the arrival times of PGA of vertical components are usually prior to that of horizontal components;( 2) the peak value ratio V / H1 is larger as the greater the intensity of seismic ground motions;( 3) the overall average of the peak value ratio V / H1 is about 0. 5,and the cumulative probability of V / H1≤0. 65 is about 84. 5%;( 4) the attenuation coefficient of the vertical response spectra is less than that of the horizontal’s; the periods of the turning points of the vertical response spectra are less than those of the horizontal response spectra; and the vertical response spectra are independent of the soil conditions.更多还原