地震频谱特性对独塔斜拉桥纵向地震响应影响

发布时间：2018-12-19 14:26

【摘要】：以一座实际的独塔斜拉桥为背景,分别以速度脉冲波和实际地震波作为地震动输入,研究了不同频谱特性地震输入下独塔斜拉桥地震响应特点.结果表明,近断层地震动的长周期速度脉冲对独塔斜拉桥的地震响应影响显著,特别是当地震动峰值速度(VP)与地面运动峰值加速度(aP)比值较大时,速度脉冲波的周期与主梁第一阶竖弯振动周期接近,塔柱、梁体、拉索和支座等受力明显增加,并可能出现支座脱空和拉索松弛等现象.进一步研究了支座脱空和拉索松弛现象,结果表明,支座脱空和拉索松弛对主梁位移、拉索索力和支座竖向反力等响应的影响较大,不考虑支座脱空和拉索松弛可能会低估梁体位移和拉索的地震响应.
[Abstract]:Taking an actual cable-stayed bridge with single tower as the background, the seismic response characteristics of the single-tower cable-stayed bridge with different spectral characteristics are studied by using the velocity pulse wave and the actual seismic wave as the ground motion input, respectively. The results show that the long-period velocity pulse of near-fault earthquake has a significant effect on the seismic response of cable-stayed bridge with single tower, especially when the ratio of local peak velocity (VP) to ground motion peak acceleration (aP) is large. The period of velocity pulse wave is close to the period of the first order vertical bending vibration of the main beam. The forces on the tower column, beam body, cable and support are obviously increased, and the phenomena of support detachment and cable relaxation may occur. The phenomena of support emptying and cable relaxation are further studied. The results show that the effects of support emptying and cable relaxation on the responses of the main beam displacement, cable force and vertical reaction force are significant. The displacement of the beam and the seismic response of the cable may be underestimated without considering the support void and cable relaxation.
【作者单位】：同济大学土木工程防灾国家重点实验室;长沙理工大学交通运输工程学院;
【基金】：同济大学土木工程防灾国家重点实验室自主课题(SLDRCE15-A-01)
【分类号】：U442.55;U448.27

【相似文献】