%0 Journal Article %T 近断层脉冲方向性对大跨斜拉桥地震响应的影响<br>Influence of directivity of near-fault impulse effect on seismic response of long span cable stayed bridge %A 陈志强 %A 郑史雄 %A 陈志伟 %A 洪成晶 %A 李晰< %A br> %A CHEN Zhiqiang %A ZHENG Shixiong %A CHEN Zhiwei %A HONG Chengjing %A LI Xi %J 铁道科学与工程学报 %D 2018 %X 由于近断层地震动脉冲特性在不同方向上差异明显，以集集地震中典型脉冲地震记录为例，比较地震动峰值加速度PGA和峰值速度PGV在各个方向上的变异性；基于连续小波变化识别出最强脉冲能量所对应的方向，比较最强脉冲方向上地震动与初始地震记录的2条水平分量脉冲性的差异；以某大跨斜拉桥为例，研究近断层地震动脉冲方向性效应对其地震响应的影响。研究结果表明：近断层脉冲地震动的峰值加速度PGA和峰值速度PGV在各个方向上差异明显，通过旋转变换以后PGA和PGV的变异性分别达到30%和70%；基于连续小波变换识别出的最强脉冲方向与PGV最大值所在的方向基本重合，最强脉冲方向上地震动的反应谱和脉冲幅值都要明显强与实测地震动记录的2条水平分量；最强脉冲方向上地震动作用下大跨斜拉桥的地震响应明显要大于实测地震记录2条水平分量作用下的结果，在近断层地区的大跨斜拉桥抗震分析时应该以最强脉冲方向上的地震动作为输入，如果直接采用实测地震记录水平分量作为地震输入则将低估桥塔和主梁的位移响应可达到45.4%和40.2%。<br>The impulse characteristics of near fault ground motion are obviously different in different directions. Therefore, the variability of peak ground acceleration (PGA) and peak ground velocity (PGV) in each direction was compared firstly based on typical pulse seismic record in Chi-Chi earthquake. And then the orientation of the strongest pulse is determined in terms of the wavelet transform. The difference of the impulse and pulse amplitude between the seismic wave of the strongest pulse direction and the initial earthquake record was compared. Finally, taking a large span cable stayed bridge as an example, the influence of the directional effect of near fault seismic impulse on its seismic response was studied in detail. The results show that: The PGA and PGV of the near fault pulse type ground motions are obviously different in each direction. After the rotation transformation, the variability of PGA and PGV reaches 30% and 70% respectively; The strongest pulse direction identified by continuous wavelet transform coincides with the direction of the maximum PGV value, and the response spectrum and pulse amplitude of the strong pulse direction are obviously stronger than the two horizontal components recorded by the recorded ground motion; The seismic response of long span cable stayed bridge under strong impulse direction is obviously larger than that of the two horizontal components of the actual seismic record, In the seismic analysis of long-span cable-stayed bridges in the near-fault area, the seismic action on the strongest impulse direction should be taken as input, otherwise, the displacement response of tower and girder can be underestimated by 45.4% and 40.2% respectively %K 脉冲方向性 %K 连续小波变换 %K 大跨斜拉桥 %K 地震响应< %K br> %K pulse directivity %K continuous wavelet transform %K long span cable stayed bridge %K seismic response %U http://www.jrse.cn/paper/paperView.aspx?id=paper_318854