摘要
柳州白沙大桥主桥为2×200 m独塔双索面钢箱梁斜拉桥,采用塔梁固结体系。桥塔为空间异形门形钢结构桥塔,由单箱矩形截面沿空间曲线扭曲而成;桥塔和斜拉索在主梁上、下游侧均反对称布置。采用MIDAS Civil软件建立主桥结构空间杆系有限元模型进行结构静力分析,通过调整塔柱中轴线线形优化桥塔结构内力,拟合出合理的塔柱中轴线方程;调整主梁高度为4.0 m和尾索靠边支点布置来提高桥梁结构刚度。在2根塔柱与主梁之间分别设置大横梁形成塔梁固结体系限制结构扭转,在梁端设置剪力卡榫抵抗横向水平反力,计入约束扭转效应情况下主梁和塔柱均满足强度及稳定要求。
The main bridge of Baisha Bridge in Liuzhou is a steel box girder cable-stayed bridge with two equal spans of 200 m. The bridge features its spatial irregular steel portal-frame pylon that is rigidly connected with the superstructure, the columns of rectangular cross-section twist along a spatial curve line to be an arch-like portal. The pylon columns and stay cables on the upstream and downstream sides are arranged in inverse symmetry. A spatial finite element model of the main bridge was built with link elements in MIDAS Civil to carry out static analysis. The axis line shape of the main pylon was modified to optimize the internal forces of the pylon, consequentially a column axis expression was fitted. To improve the stiffness of the pylon, a pylon-girder fixation system was selected, the depth of the steel box girder was adjusted to 4.0 m and the longest stay cables were stretched to anchor at the locations close to the supports. To limit the rotation of the superstructure, a large crossbeam is added between the two pylon columns and the superstructure to form a pylon-girder fixation system. Shear tenons are installed at the ends of the superstructure to resist horizontal reaction force. When the torsion-restricting force is considered, the strength and stability of the superstructure and pylon columns can meet the requirements.
作者
张先蓉
王碧波
ZHANG Xian-rong;WANG Bi-bo(China Railway Major Bridge Reconnaissance&Design Group Co.,Ltd.,Wuhan 430056,China)
出处
《世界桥梁》
北大核心
2023年第2期14-20,共7页
World Bridges
关键词
独塔斜拉桥
反对称结构
桥塔中轴线方程
塔梁固结
结构刚度
约束体系
桥梁设计
single pylon cable-stayed bridge
inverse symmetry
bridge axis line expression
pylon-girder fixation
structural stiffness
restraint system
bridge design
