下承式钢系杆拱桥中央拱肋稳定性分析  

Stability analysis of central arch rib structure of lower steel tied arch bridge

作　　者：周建波 ZHOU Jianbo(Central and Southern China Municipal Engineering Design&Research Institute Co.,Ltd.,Wuhan 430010,Hubei,China)

机构地区：[1]中国市政工程中南设计研究总院有限公司,湖北武汉430010

出　　处：《工程建设》2023年第6期22-27,共6页Engineering Construction

摘　　要：对于大跨下承式系杆拱桥,中央拱肋一般呈细长柔性杆件特点,稳定问题较为突出。本文以某拱桥为例,建立全桥有限元模型,分析拱肋刚度、倾角、系梁刚度、横撑刚度对中央拱肋稳定性的影响。结果表明:1)中央拱肋低阶失稳模态为侧向对称失稳;2)拱肋面外刚度对自身稳定性的影响强于面内刚度;3)拱肋倾角对自身稳定性的影响有抛物线特点,在倾角为6°左右时,线弹性稳定系数达最大值;4)系梁任何一维刚度增大均会增加拱肋线弹性稳定系数,其中侧向刚度影响最大;5)横撑刚度和间距对拱肋稳定性的影响强于拱肋刚度、倾角及系梁刚度,合理设置横撑是提高拱肋稳定性的有效手段。For the long-span bottom-tie arch bridge,the central arch rib is generally fine and soft,and the stability problem is more prominent.Taking Gaojiaba arch bridge as an example,a finite element model of the whole bridge is canstructed,and the effects of arch rib stiffness,dip Angle,tie beam stiffness,transverse brace stiffness on the stability of the central arch rib were analyzed.The results show that:1)the low order instability mode of the central arch rib is lateral symmetric instability;2)The influence of the out-of-plane stiffness on the stability of the arch rib is stronger than that of the in-plane stiffness;3)The influence of the dip angle of the arch rib on its stability has a parabolic characteristic,and the linear elastic stability coefficient reaches the maximum when the dip angle is about 6°;4)The increase of any one-dimensional stiffness of the girder will increase the elastic stability coefficient of the arch rib,and the lateral stiffness has the greatest effect;5)The influence of transverse brace stiffness and spacing on arch rib stability is stronger than that of arch rib stiffness,dip angle and tie beam stiffness.Reasonable setting of transverse brace is an effective means to improve arch rib stability.

关 键 词：中央拱肋 低阶失稳模态 拱肋倾角 线弹性稳定系数 有限元分析 

分 类 号：U448.225[建筑科学—桥梁与隧道工程]