公铁平层斜拉桥超宽幅钢箱梁节段模型试验及活载作用效应研究  

Model Tests on Ultra-wide Steel Box Girder Section of Cable-stayed Rail-cum-road Bridge and Study on Effect of Live Loads

作　　者：李刚[1] 肖林[1] 张伟勇 卫星[1] 赵骏铭 温宗意 LI Gang;XIAO Lin;ZHANG Weiyong;WEI Xing;ZHAO Junming;WEN Zongyi(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Southern Sichuan Intercity Railway Co.,Ltd.,Zigong 643002,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]川南城际铁路有限责任公司,四川自贡643002

出　　处：《铁道学报》2023年第3期47-54,共8页Journal of the China Railway Society

基　　金：国家自然科学基金(52078424);四川省铁路产业投资集团有限责任公司科技计划(SRIG2022GG0001)。

摘　　要：为研究公铁平层斜拉桥超宽幅钢箱梁受力特性和活载作用效应,以宜宾临港长江大桥宽度为63.9 m的超宽幅钢箱梁节段为研究对象,设计制作相似比为1∶10的全截面缩尺模型开展静载模型试验,并进行有限元计算分析,分别研究恒载状态、公路车辆荷载作用、铁路列车荷载作用及不同活载组合作用下超宽幅箱梁受力特性,纵、横向正应力分布情况及梁体变形特征。结果表明,该桥超宽幅钢箱梁横向弯曲受力行为显著,梁体在活载作用下表现为挑担式支撑梁力学特性和变形特征,其中梁体中箱在铁路列车荷载作用下表现为正弯矩简支梁受力特性,梁体两侧边箱在公路车辆荷载及人群非机动车辆荷载作用下表现为负弯矩悬臂梁受力特性,梁体横截面设计合理,活载作用机理明确,中、边箱结构传力清晰。研究成果为超宽幅钢箱梁的设计和施工提供了重要的参考和设计依据,并为类似桥梁设计提供指导。To study the mechanical characteristics and live load effect of the ultra-wide steel box girder of the cable-stayed rail-cum-road bridge,based on the study of the ultra-wide steel box girder section of Yibin Lingang Yangtze River Bridge with a width of 63.9 m,a model of the composite structure with a scale of 1[DK]∶10 was designed and constructed for static load model tests and finite element analysis,where the mechanical characteristics,longitudinal and transverse normal stress distribution and beam deformation characteristics of the ultra-wide steel box girder were investigated under the dead load condition,road vehicle load condition,railway train load condition and combination of different live load conditions.The results show that the box girder of the bridge has a significant lateral bending force behavior,with the girder body exhibiting the mechanical properties and deformation characteristics of a shoulder-supported girder under the live load conditions.The middle box shows the mechanical characteristics of a simply supported beam with positive bending moment under the load of the railway train,while the side boxes of the beam show the mechanical characteristics of the cantilever beam with a negative bending moment under the load of the road vehicles,pedestrians and non-motor vehicles,showing reasonable design of the cross-section of the girder body,clear live load action mechanism,and clear force transmission of the middle and side box structures.The research results provide important reference and design basis for the design and construction of ultra-wide steel box girders,and provide guidance for the design of similar bridges.

关 键 词：公铁平层斜拉桥 超宽幅钢箱梁 模型试验 活载作用 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]