大跨径钢箱梁桥正交异性板疲劳裂纹发展规律及处置措施  

Propagation Rule and Treatment Measures of Fatigue Crack in Orthotropic Deck of Long-span Steel Box Girder Bridge

作　　者：刘汉勇[1] 代希华 程寿山[1] LIU Han-yong;DAI Xi-hua;CHENG Shou-shan(Research Institute of Highway,Ministry of Transport,Beijing 100088,China;Guangdong Provincial Highway Construction Co.,Ltd.,Guangzhou Guangdong 510405,China)

机构地区：[1]交通运输部公路科学研究院,北京100088 [2]广东省公路建设有限公司,广东广州510405

出　　处：《公路交通科技》2022年第8期32-38,共7页Journal of Highway and Transportation Research and Development

基　　金：广东省重点领域研发计划项目(2019B111106001)。

摘　　要：为掌握在用大跨径钢箱梁桥正交异性板疲劳裂纹的发展规律,探寻延长正交异性板使用寿命的加固措施,针对当前正交异性钢桥面板普遍存在的疲劳开裂现状,以国内某大型悬索桥钢箱梁正交异性板为研究对象,采用目视检查与磁粉探伤相结合的方法,检查统计了该桥正交异性板的可见裂纹和疑似隐性裂纹数量。根据疲劳裂纹检查结果,分析了其疲劳裂纹发展与近7 a的日均交通量的关联关系。从力学性能、构造措施与焊接工艺3方面进行了疲劳裂纹开裂机理分析,明晰了5类疲劳裂纹萌生和发展的机理。在此基础上,针对每一类疲劳裂纹给出了修复方法。为改善正交异性钢桥面板的整体受力性能,提出了增加空腹式横隔板的正交异性板钢箱梁加固措施,以该桥钢箱梁标准段为实际案例,设计了空腹式横隔板加固方案,并对增加空腹式横隔板后的钢箱梁标准段进行了有限元分析。结果表明:除Ⅳ类疲劳裂纹与交通量不存在明显相关性以外,其余疲劳裂纹(Ⅰ,Ⅱ,Ⅲ,Ⅴ,Ⅵ类)的形成原因均与交通量增长有较密切的相关性。提出的方法可以显著降低正交异性板疲劳细节处的应力水平,改善正交异性钢桥面板的受力性能,提高正交异性板的疲劳寿命。根据研究结果,建议将常规疲劳裂纹修复,并增加空腹式横隔板作为在用钢箱梁正交异性板的有效加固措施。In order to master the fatigue crack propagation rule of orthotropic deck in long-span steel box girder bridge in service,explore the reinforcement measures for prolonging the orthotropic deck service life.In view of the common fatigue cracking of orthotropic steel bridge decks,taking the orthotropic deck of steel box girder of a large suspension bridge in China as the investigation object,the number of visible cracks and suspected hidden cracks of the orthotropic steel box girder decks are checked and counted by means of visual inspection and magnetic particle inspection.According to the result of fatigue crack inspection,the relationship between the propagation of fatigue cracks and the daily traffic volume in recent 7 years is analyzed.The mechanism of fatigue cracks is analyzed from the aspects of mechanical properties,structural measures and welding technology,and the mechanism of initiation and propagation of 5 kinds of fatigue cracks is clarified.On this basis,the repair method for each type of fatigue crack is given.In order to improve the overall mechanical performance of orthotropic steel bridge decks,the reinforcement measure for orthogonal deck steel box girder with the addition of the hollow diaphragm is proposed.Taking the standard section of the steel box girder of the bridge as a practical case,the reinforcement scheme of hollow diaphragm is designed,and the finite element analysis of the standard section of the steel box girder with the addition of the hollow diaphragm is carried out.The result shows that(1) the formation of fatigue cracks(class Ⅰ,class Ⅱ,class Ⅲ,class Ⅴ and class Ⅵ) are closely related to the growth of traffic volume,except for class IV fatigue cracks which has no obvious correlation with the traffic volume.The proposed method can significantly reduce the stress level at the fatigue detail of orthotropic steel deck,improve the mechanical performance of orthotropic steel bridge deck,and enhance the fatigue life of orthotropic steel deck.According to the research result,

关 键 词：桥梁工程 疲劳裂纹处置措施 数值模拟 正交异性钢桥面板 疲劳裂纹发展规律 

分 类 号：U443.33[建筑科学—桥梁与隧道工程]