具有刚性中央扣的大跨度悬索桥随机地震响应研究

发布时间：2018-06-18 22:39

本文选题：大跨度悬索桥 + 刚性中央扣　；参考：《世界桥梁》2017年03期

【摘要】：为分析刚性中央扣对悬索桥地震响应的影响,以一座具有刚性中央扣的大跨度悬索桥为例,建立大跨度悬索桥的空间有限元模型,基于随机振动法对比分析刚性中央扣对悬索桥动力特性的影响、地震动功率谱密度函数的选择对地震响应的影响以及悬索桥在三向地震作用下的地震响应。结果表明:刚性中央扣减少了加劲梁纵飘及与主缆振动相关振型出现的次数并增大了相应的频率;在纵向地震作用下,中央扣减小了加劲梁的位移,但是明显增大了加劲梁的内力;地震动功率谱密度函数模型采用Clough-Penzien模型时所得到的随机地震响应要较杜修力模型大,且两者的计算结果均大于采用规范反应谱的计算结果;在三向地震作用下,导致加劲梁在中央扣位置处形成内力集中,地震响应也更为不利,桥塔最大纵向弯矩位于塔底,最大横向弯矩位于横梁交界处和塔底。
[Abstract]:In order to analyze the effect of rigid central buckle on seismic response of suspension bridge, a spatial finite element model of long-span suspension bridge with rigid central buckle was established. Based on the random vibration method, the influence of rigid central buckle on the dynamic characteristics of suspension bridge, the influence of the selection of power spectrum density function of ground motion on the seismic response and the seismic response of suspension bridge under the action of triaxial earthquake are analyzed. The results show that the rigid central buckle reduces the frequency of longitudinal floating of stiffened beam and the modes associated with the vibration of the main cable and increases the corresponding frequency, and the displacement of stiffened beam decreases under the action of longitudinal earthquake. However, the internal force of stiffened beam is obviously increased, and the random seismic response of Clough-Penzien model is larger than that of Duxiu force model, and the calculated results of both models are larger than those of normal response spectrum. Under the action of triaxial earthquake, the internal force concentration of stiffened beam is formed at the central buckling position, and the seismic response is even more unfavorable. The maximum longitudinal moment of bridge tower is located at the bottom of the tower, and the maximum transverse moment is located at the junction of beam and tower bottom.
【作者单位】：中交第二公路勘察设计研究院有限公司;
【分类号】：U442.55;U448.25

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