大跨径不对称斜拉桥二次转体称重试验研究  

Research on Two-Stage-Rotation Weighing Test for Long-Span Asymmetric Cable-Stayed Bridge

作　　者：索小灿 孔华 严和仲 李川 茅建校[4] SUO Xiao-can;KONG Hua;YAN He-zhong;LI Chuan;MAO Jian-xiao(China Railway Bridge&Tunnel Technologies Co.,Ltd.,Nanjing 210061,China;Fujian Longyan Urban Construction Investment Development Co.,Ltd.,Longyan 364031,China;China Construction Sixth Engineering Bureau Group Co.,Ltd.,Tianjin 300171,China;Southeast University,Nanjing 210096,China)

机构地区：[1]中铁桥隧技术有限公司,江苏南京210061 [2]福建省龙岩市城市建设投资发展有限公司,福建龙岩364031 [3]中国建筑第六工程局有限公司,天津300171 [4]东南大学,江苏南京210096

出　　处：《世界桥梁》2023年第S01期110-116,共7页World Bridges

基　　金：国家自然科学基金项目(52108274)。

摘　　要：龙岩大桥主桥为(190+150)m独塔不对称双索面钢箱梁斜拉桥,跨越既有铁路线,采用裸塔单转和塔梁共转的二次转体施工工艺。针对该桥结构特点,转体称重试验采用球铰竖向转动法,提出不对称转体桥梁二次配重试验方案,即先通过一期配重加载和球铰位移变化的实时监测,将不对称转体结构调整至不平衡力矩小于球铰摩阻力矩状态;再进行称重试验,得出二次精确配重,完成转体平衡配重的布置。试验结果表明:实测两次转体球铰静摩擦系数分别为0.022和0.037,小于0.05,球铰静摩擦系数均满足设计要求;按二次精确配重加载后,校核转体结构重心偏心距仅为7 mm,满足平衡转体要求;该桥两次转体时间间隔4.5个月,第二次转体过程实测塔顶最大偏位为0.1 m,最大撑脚间隙变化为5 mm,撑脚未着地,球铰工作性能良好,实现了平衡转体的目标。The main bridge of Longyan Bridge is a steel box girder cable-stayed bridge that features its single pylon,which creates two asymmetric spans of 190 m and 150 m.Due to that the bridge crosses existing railways,a two-stage rotation construction scheme was selected,incorporating the first-stage rotation of the bare pylon and the second-stage collaborative rotation of the pylon and the superstructure.Considering the structural characteristics of the bridge,a spherical hinge that permits vertical rotation was employed in the weighing test of the structures rotated,and a"two-stage counterweighting"plan for the asymmetric bridge rotation construction was proposed,namely in the first stage,to adjust the asymmetric structures rotated to a state where the unbalanced moment is less than the friction moment of the spherical hinge;in the second stage,to carry out the weighing test to obtain accurate second-stage counterweights,to complete the distribution of counterweights on the asymmetric structures rotated.In the test,the static friction coefficients of the spherical hinge in the first-and second-stage rotations were 0.022 and 0.037,respectively,below 0.05,indicating that the friction coefficient of the spherical hinge meets the design requirements.Loaded with accurate second-stage counterweights,the gravity center eccentricity was calibrated to be only 7 mm,meeting the balance rotation requirements.The second-stage rotation was conducted 4.5 months after the completion of the first-stage rotation.The maximum pylon-head offset measured in the second-stage rotation was 0.1 m,the maximum spacing variation between stands of the spherical hinge was 5 mm,and the stands did not touch the ground,proving that the spherical hinge worked well.By using the proposed construction scheme,the Longyan Bridge achieved the objective of balanced rotation construction.

关 键 词：不对称斜拉桥 跨线桥 二次转体 球铰 静摩擦系数 配重 称重试验 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.465[交通运输工程—道路与铁道工程]