摘要
为研究高速铁路多塔斜拉桥力学行为,以某高铁黄河桥为背景,对主跨5×260 m六塔斜拉桥进行结构参数及受力特性研究。结果表明:5主跨斜拉桥主梁竖向刚度约为单主跨斜拉桥的0.5倍;能显著控制塔顶水平位移的措施可有效改善主桥总体刚度,如采用刚性塔、加劲索;温度、收缩徐变引起长联主梁伸缩,对边塔形成“拖拽”效应,桥塔两侧索力变化使梁体产生附加竖向变形,进而影响轨道不平顺及残余徐变变形,并在边塔塔底产生较大内力,设计中通过延长桥塔成桥静置时间、减少主跨混凝土梁长度来减小梁体工后徐变,通过减小边塔相对刚度来降低温度对轨道不平顺影响。
To study the mechanical behavior of multi-pylon cable-stayed bridges of high speed railways, the Yellow River bridge of a high speed railway is taken as an example and the structural parameters and mechanical characteristics of six-pylon cable-stayed bridge with 5×260 m main spans are studied. The results show that the vertical stiffness of the main girder of the cable-stayed bridge with 5 main spans is about0. 5 times of that of the cable-stayed bridge with 1 main span;measures that can significantly control the horizontal displacement at the top of the pylons, such as using rigid pylons and stiffening cables, can effectively improve the overall stiffness of the main bridge;temperature and shrinkage creep cause expansion and contraction of the long main girder, and the“drag”effect on the side pylons. The change of cable force on both sides of the pylons causes additional vertical deformation of the girder body, further leading to track irregularity and residual creep deformation, and generating large internal force at the bottom of the side pylons. In the design, the post-construction creep of the girder body is reduced by extending the standstill time of the completed pylons and reducing the length of the main span concrete girder, the impact of temperature on track regularity is mitigated by reducing the relative stiffness of the side pylons.
作者
牟兆祥
张上
刘凯
MU Zhaoxiang;ZHANG Shang;LIU Kai(Civil Engineering Design Research Institute,China Railway Design Corporation,Tianjin 300308,China)
出处
《中国铁路》
2022年第4期35-42,共8页
China Railway
基金
中国铁路设计集团有限公司科技开发计划项目(2020YY340622)。
关键词
高速铁路
多塔斜拉桥
总体刚度
力学行为
结构设计
high speed railway
multi-pylon cable-stayed bridge
overall stiffness
mechanical behavior
structural design
