三塔悬索桥结构竖向刚度及主缆抗滑需求  

Requirements of vertical stiffness and anti-slip safety for three-pylon suspension bridge

作　　者：沈锐利[1] 侯康 王路[1] Shen Ruili;Hou Kang;Wang Lu(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;CCCC Highway Consultants Co.,Ltd.,Beijing 100088,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]中交公路规划设计院有限公司,北京100088

出　　处：《东南大学学报（自然科学版）》2019年第3期474-480,共7页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51178396);浙江省交通运输厅科技计划资助项目(2011H03)

摘　　要：为研究不同跨径三塔悬索桥对于结构竖向刚度及主缆抗滑安全的综合需求特征,构建了主跨500~1 500 m范围内的6座三塔悬索桥计算模型,通过改变中塔纵向刚度,对加劲梁竖向挠度及主缆抗滑安全系数进行了计算分析,并探讨了将主缆抗滑安全系数限值进行折减的合理性.研究表明:跨径越大的三塔悬索桥越易满足结构竖向刚度及主缆抗滑安全的要求,有效缓解了中塔效应问题;中塔纵向刚度对结构刚度、塔顶偏位及主缆抗滑安全系数均有较大影响,但该影响随中塔纵向刚度的提高而趋于恒定;适当增大缆鞍间摩擦系数后,三塔悬索桥桥跨布置及中塔纵向刚度的合理设计区间大幅拓宽;杆系模型配合规范计算公式得出的主缆抗滑安全系数要比多尺度模型结果小21%~30%,因此建议可偏保守地对规范抗滑安全系数限值进行15%的折减,即由2.0降低至1.7.To study the comprehensive requirements of vertical stiffness and anti-slip safety for three-pylon suspension bridge with different spans, the model of six three-pylon four-span suspension bridges distributed from 500 to 1 500 m was established. By the adjustment of the longitudinal stiffness of the mid-pylon, the vertical deflection of the girder and the anti-slip safety factor of the main cable were calculated and analyzed. The rationality of reducing the limits of the anti-slip safety factor was discussed. The results show that the larger three-pylon suspension bridges can satisfy the requirements of the deflection-span ratio and the anti-slip safety factor more easily, relieving the problem of the mid-pylon effect effectively. The longitudinal stiffness of mid-pylon has a great influence on the vertical stiffness, the longitudinal deviation of mid-pylon, and the anti-slip safety factor of the main cable, and these influences tend to be stable with the increase of the longitudinal stiffness of mid-pylon. With the increase of the friction coefficient between the main cable and the saddle, the applicable scope of the three-pylon suspension bridge and the longitudinal stiffness of the mid-pylon is expanded significantly. The anti-slip safety factor obtained by the bar system model cooperated with standard calculation formula is smaller by 21%-30% than that calculated from multi-scale refinement model. Therefore, it is suggested that a reduction of 15% can be carried out conservatively to the limit of the anti-slip safety factor calculated by the standard calculation formula;i.e., from 2.0 to 1.7.

关 键 词：多塔悬索桥 中塔效应 结构竖向刚度 抗滑安全系数 中塔纵向刚度 名义摩擦系数 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]