半分离式斜腹板双箱梁大跨单肋拱桥颤振临界风速分析  

Critical Flutter Wind Velocity Analysis of Long-Span Arch Bridge Featuring Single Arch and Deck System Consisting of Double Semi-Separated Box Girders with Inclined Webs

作　　者：张静 詹刚毅 汪斌[3] ZHANG Jing;ZHAN Gangyi;WANG Bin(Sichuan Tibet Railway Co.,Ltd.,Chengdu 610031,China;Chengdu Southwest Jiaotong University Design and Research Institute Co.,Ltd.,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu,610031)

机构地区：[1]川藏铁路有限公司,四川成都610031 [2]成都西南交通大学设计研究院有限公司,四川成都610031 [3]西南交通大学土木工程学院,四川成都610031

出　　处：《世界桥梁》2024年第4期85-91,共7页World Bridges

基　　金：国家自然科学基金面上项目(52278535);四川省自然科学基金面上项目(2022NSFSC0428)。

摘　　要：为研究低扭弯频率比大跨度桥梁的颤振性能,以某主跨180 m的半分离式斜腹板双箱梁大跨单肋拱桥为背景(主梁扭弯频率比接近1.0),进行颤振临界风速分析。采用有限元法分析该桥动力特性,计算桥梁颤振稳定性;对比《公路桥梁抗风设计规范》(JTG/T 3360-01—2018)推荐的3组理想平板颤振临界风速估算公式,基于Scanlan半逆解法的理想平板颤振临界风速,考虑主梁形状与攻角修正系数确定颤振临界风速范围;采用强迫振动数值模拟识别颤振导数,获得精确颤振临界风速,进一步计算半分离式斜腹板双箱梁的形状和攻角系数。结果表明:该桥主梁扭弯频率比较低,颤振稳定性低于500 m级大跨度双肋拱桥;规范推荐的理想平板颤振临界风速估算公式在小扭弯频率比时差异较大;半分离式斜腹板双箱梁形状修正系数小于分离式双箱梁而大于P-K梁、带斜腹板箱梁,攻角修正系数略大于这3种形式主梁。This study focuses on the flutter performance of the long-span bridge with low torsion-bending frequency ratio.Based on an existing long-span arch bridge featuring its single arch that spans 180 m,the deck system consisting of double semi-separated steel box girders with inclined webs and a low torsion-bending frequency ratio approximating 1.0,the critical flutter wind velocities were analyzed.The dynamic property of the bridge was simulated to calculate the flutter stability of the bridge.Three groups of formulae to predict the critical flutter wind velocities of ideal flat plates recommended in Wind-Resistant Design Specification for Highway Bridges(JTG/T 3360-01-2018)were compared.Based on the critical flutter wind velocities of ideal flat plates by the Scanlan semi-inverse solution,considering the geometry of the deck and the correction factor of wind attack angles,the ranges of the critical flutter wind velocities are determined.Furthermore,the forced vibrations were numerically simulated to identity flutter derivatives to obtain the accurate critical flutter wind velocities.Consequently,the geometry and coefficients of wind attack angles of the double semi-separated box girders were calculated.As per the analysis,the bridge exhibits low torsion-bending frequency ratios,and the flutter stability is lower than the long-span arch bridges with a main span of 500 m.For the formulae to predict the critical flutter wind velocities of the ideal flat plate recommended by the specification,the results reveal great disparity at the small torsion-bending frequency ratio.The geometry correction factor of the double semi-separated box girder is smaller than that of the double separated box girders,but greater than the PK section girder and the box girder with inclined webs,while the correction factors of the wind attack angles are bigger than the other three types of main girder.

关 键 词：大跨度拱桥 单肋式拱桥 半分离式斜腹板双箱梁 颤振临界风速 形状修正系数 攻角修正系数 数值模拟 

分 类 号：U448.22[建筑科学—桥梁与隧道工程] U441.3[交通运输工程—道路与铁道工程]