沪苏通长江公铁大桥大跨柔性拱拼装与竖转过程分析  

Analysis of Assembly and Vertical Rotation Process of Flexible Long-Span Arch of Shanghai-Suzhou-Nantong Changjiang River Rail-cum-Road Bridge

作　　者：薛志武 周明生 XUE Zhi-wu;ZHOU Ming-sheng(CCCC Wuhan Harbor Engineering Design&Research Co.,Ltd.,Wuhan 430040,China;Hubei Key Laboratory of Advanced Materials&Reinforcement Technology Research for Marine Environment Structures,Wuhan 430040,China;China Communications 2nd Navigational Bureau 2nd Engineering Co.,Ltd.,Chongqing 401121,China)

机构地区：[1]中交武汉港湾工程设计研究院有限公司,湖北武汉430040 [2]海工结构新材料及维护加固技术湖北省重点实验室,湖北武汉430040 [3]中交二航局第二工程有限公司,重庆401121

出　　处：《世界桥梁》2021年第4期77-83,共7页World Bridges

基　　金：中国交通建设股份有限公司科研课题(2014-ZJKJ-27)。

摘　　要：沪苏通长江公铁大桥天生港专用航道桥为主跨336 m的钢桁梁柔性拱桥,拱肋在钢桁梁上组拼成半拱,利用扣塔竖向转体,单边拱竖转重量约1400 t。为选择合适的拱肋拼装和竖转施工控制措施及参数,采用MIDAS Civil软件建立有限元模型,计算3种不同拱肋拼装施工控制措施下钢桁梁的应力和变形,并分析拱肋竖转过程中拱肋受力、整体稳定性及参数敏感性。结果表明:通过边跨压重、单边拱提前预张扣索50%索力,可有效降低钢桁梁应力峰值和下挠量,确定为拱肋拼装施工控制措施;按计算的背索和牵引索试转索力和转体到位索力进行拱肋竖转,结构受力满足要求;拱肋转体的低阶稳定系数大于4,拱肋转体到位整体稳定性满足要求;按转体过程同层牵引索相对索力偏差不超过10%、背索与设计索力偏差小于10%、转铰同轴度偏差小于10 mm进行施工控制,拱肋合龙控制结果满足要求。The Tianshenggang Navigational Channel Bridge of Shanghai-Suzhou-Nantong Changjiang River Rail-cum-Road Bridge is a steel truss girder and flexible arch bridge with a main span of 336 m.The arch rib was assembled on the steel truss girder to be two halves that would be rotated into position by a tower and fastening cables system,and the rotation weight on each side was about 1400 t.To find the proper arch rib assembly and vertical rotation control measures as well as the appropriate parameters,the finite element model was established by MIDAS Civil,to calculate the stress and deformation of the steel truss girder when three different arch rib assembly and vertical rotation control measures were used.The load bearing behavior,global stability and parametric sensitivity of the arch rib during the vertical rotation process were analyzed.The results show that when the side spans were counterbalanced,and the fastening cables of each half of the arch rib were stressed to 50%of the cable forces,the stress peaks and deflection of the steel truss girder could be effectively flattened,thus determined as the arch rib assembly and vertical rotation control measure.The arch ribs were vertically rotated following the calculations of the forces of the back stays and traction stays during the trial rotation and in the final position,which proved that the load bearing capacity of the structure could reach the required level.The lower-mode stability coefficient for the arch rib rotation was greater than 4.When the arch ribs were rotated into position,the global stability of the structure could meet the requirements.During the rotation,the relative forces of the traction cables in the same layer did not exceed 10%,the difference of the measured and design forces of the back stays was less than 10%,the deviation of concentricity of the rotation hinge was below 10 mm,and the closure control result of the arch rib met the requirements.

关 键 词：拱桥 拱肋 拼装 竖转 力学性能 有限元法 施工控制 

分 类 号：U448.22[建筑科学—桥梁与隧道工程] U445.1[交通运输工程—道路与铁道工程]