三塔悬索桥中塔设计方法研究  

Research on Middle Tower Design Method of Three-Tower Suspension Bridge

作　　者：董学智 万田保[1] 唐贺强[1] 罗扣[1] 俞晶晶 DONG Xue-zhi;WAN Tian-bao;TANG He-qiang;LUO Kou;YU Jing-jing(China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430056,China;State Grid Hubei Extra High Voltage Company,Wuhan 430050,China)

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430056 [2]国网湖北省电力有限公司超高压公司,湖北武汉430050

出　　处：《世界桥梁》2023年第1期38-43,共6页World Bridges

基　　金：中国中铁股份有限公司科技研究开发计划项目(2020-重大-01)。

摘　　要：为提高三塔悬索桥中塔设计效率,提出基于中塔纵向刚度区间进行中塔设计的方法。该方法在总体计算模型中将中塔等效为一根弹簧,根据全桥竖向刚度和主缆抗滑要求试算纵向刚度,得到中塔纵向刚度区间;从中选择合理的初始值进行中塔设计;将中塔代入全桥计算模型进行迭代计算,调整中塔材料和几何参数直至各项指标均满足规范要求。利用已建成的4座公路三塔悬索桥对该方法的准确性进行验证,同时构建公铁两用三塔悬索桥算例,应用该方法进行中塔设计。结果表明:3座公路三塔悬索桥中塔实际纵向刚度均在本文确定的纵向刚度区间内,且取实际中塔纵向刚度时,等效模型与实际全桥模型计算的活载挠度、主缆抗滑安全系数最大差异为8.1%;公铁两用三塔悬索桥算例的中塔纵向刚度设计终值与纵向刚度初始值的差异为13.9%,与常规桥塔设计方法相比迭代次数减少,设计效率提高。A middle tower design method based on the longitudinal stiffness interval is proposed,which can improve the middle tower design efficiency of the three-tower suspension bridge.In the overall calculation model,the middle tower is equivalent to a spring,whose longitudinal stiffness is predicted,taking into account the demands of vertical stiffness of the overall bridge and the sliding resistance of main cables,and in turn,the longitudinal stiffness interval of the middle tower is obtained.The rational initial data are chosen for middle tower design.Afterwards,the expression of the middle tower is substituted into the overall bridge computing model for iterative calculation,during this course,the parameters of materials and middle tower geometry are kept adjusting till all the indexes meet the code requirements.Four existing three-tower road suspension bridges were employed as study cases to verify the correctness of the proposed method.Meanwhile,the expressions of three-tower rail-cum-road suspension bridge were formulated,and based on which,the proposed method was applied for middle tower design.It is shown that the actual longitudinal stiffness of the middle towers of three three-tower road suspension bridges are within the longitudinal stiffness interval proposed in this paper.When the real longitudinal stiffness of a middle tower is input,the maximum difference between the equivalent model and the overall finite element model of a real bridge reaches 8.1%,concerning the live load deflection and anti-sliding safety factor.For a three-tower rail-cum-road suspension bridge,the difference between the design longitudinal stiffness of the middle tower and the initial value of longitudinal stiffness is at 13.9%,indicating less iteration times and improved design efficiency,compared with the conventional bridge tower design method.

关 键 词：三塔悬索桥 中塔 等效模型 纵向刚度 竖向刚度 主缆抗滑 桥梁设计 

分 类 号：U443.131[建筑科学—桥梁与隧道工程] U442.5[交通运输工程—道路与铁道工程]