【摘要】 根据桥梁所在场地条件,选择合理的谱加速度衰减关系生成场地中值加速度反应谱,选择合理的持时衰减关系,抽取持时样本,生成2个匹配场地中值加速度反应谱的人工波库,对1座钢筋混凝土桥墩进行非线性动力时程分析,将持时对于EDP概率预计和PSDM的影响与幅值和频谱的影响进行解耦。得到以下结论:(1)考虑持时的分布与否对于EDP概率预计的影响不大,但可以有效地减小离散度,而且对能量需求参数的影响大于对位移需求参数。(2)当选择结构第1模态周期谱加速度和合理的能量需求参数分别作为地面运动强度参数和EDP建立概率地震需求模型时,可以通过选择地震波来考虑持时的影响。更多还原

【Abstract】 The median acceleration response spectrum and samples of duration were obtained from the reasonable spectral acceleration attenuation relationship and duration attenuation relationship respectively according to site conditions.Two bins of artificial accelerograms compatible with the median acceleration response spectra were generated.The influences of duration,frequency spectrum and amplitude on EDP probability estimates and PSDM were uncoupled.The conclusions are drawn that(1)EDP probability estimates are influenced seldom but dispersions are reduced effectively whether considering duration distribution or not,the influence on energy EDP is more than on displacement EDP;(2)when the first mode period spectral acceleration and reasonable energy EDP are regarded as intensity measure(IM) and EDP respectively to develop probabilistic seismic demand models(PSDMs),the influence of the probability distribution of duration can be considered by the selection of earthquake strong-motions.更多还原