摘要
越东大桥为主跨400 m钢—混组合梁斜拉桥,其索塔采用了水滴形曲线混凝土结构。受自重及施工荷载等影响,塔柱在倾斜悬臂状态下,根部截面处易形成较大弯矩并造成混凝土出现较大拉应力,需设置内支撑以降低索塔施工过程中的结构内力。利用有限元方法,对3种不同临时支撑方案下的索塔受力变形进行了对比分析,基于计算结果探讨了不同支撑方案的可行性,在综合考虑结构受力安全性和经济效益的条件下确定了索塔实际支撑方案。同时,在索塔施工过程中对关键截面应力与索塔线形进行了监控量测,将测试数据与有限元计算结果进行了对比。研究结果表明,上塔柱内设置单道支撑时,无法及时提供横向抗变形刚度以抵抗由上横梁施工造成的横向位移;索塔合龙后整体横向位移随横撑布设数量增大呈减小趋势;中塔柱采用2道支撑和3道支撑计算得到的索塔合龙后的横向位移分布及峰值均较为接近,工程中选用了在中塔柱和上塔柱各设置2道横撑的方案;监测数据与有限元模拟结果吻合良好,索塔合龙后索塔整体线形与理论线形基本一致。
The Yuedong Bridge is a steel-concrete composite girder cable-stayed bridge with a main span of 400 meters,the tower adopting a water droplet-shaped curve concrete structure.Due to the influence of self-weight and construction load,large bending moment can easily form at the base section of the inclined cantilever state of the tower columns,causing significant tensile stress in the concrete,internal supports are needed to reduce the structural internal forces during the construction of the tower. In thestudy, the finite element method is used to compare and analyze the force deformation of the tower underthree different temporary support schemes and discusses the feasibility of different support options basedon the computational results. Taking into account the structural safety and economic efficiency, the actualsupport scheme for the tower is determined. At the same time, during the construction of the tower,stress monitoring at critical sections and the profile of the tower are conducted. The test data are comparedwith the finite element calculation results. The research results show that when a single internal support isset up in the upper tower column, it cannot provide lateral deformation resistance in time to counteract thelateral displacement caused by the construction of the upper beam;after the tower is closed, the overalllateral displacement of the tower decreases with the increase in the number of lateral braces;the lateraldisplacement distribution and peak values after the tower is closed are relatively close when using two orthree supports in the middle tower column. In the project, two lateral braces are selected for both themiddle and upper tower columns (the second scheme). The monitoring data and the finite elementsimulation results are in good agreement, and after the tower closure, the overall profile of the tower isbasically consistent with the theoretical profile.
作者
章文彬
杨康
郝笛笛
宋正锋
吕悦凯
缪长青
万春风
ZHANG Wen-bin;YANG Kang;HAO Di-di;SONG Zheng-feng;LYU Yue-kai;MIAO Chang-qing;WAN Chun-feng(The Fourth Engineering Company,CCCC Second Harbor Engineering Co.Ltd.,Wuhu 2410o1,China;Key Laboratory of Concrete and Prestressed Concrete Structure of Ministry of Education,Southeast University,Nanjing 21oo96,China;School of Civil Engineering,Southeast University,Nanjing 211189,China;China-Road Transportation Verification&Inspection Hi-Tech Co.Ltd.,Beijing 10o080,China)
出处
《公路》
北大核心
2024年第10期94-102,共9页
Highway
基金
国家自然科学基金项目,项目编号52178119。
关键词
桥梁工程
钢—混组合梁斜拉桥
水滴形索塔
有限元分析
支撑方案
施工监控
bridge engineering
steel-concrete composite beam
water-drop shaped cable tower
finite element analysis
support scheme
construction monitoring
