摘要
为研究铁路双边箱混合梁斜拉桥钢-混结合段的受力性能和传力机理,优化其构造形式与尺寸,取消了实桥初步设计的前承压板、钢梁埋入段、钢格室并最大限度减小剪力连接件密度,设计制作了缩尺比为1∶2.5的钢-混结合段试验模型,分析实桥各设计验算工况下结合段的应力分布、承载性能及剪力传力特征,并建立板壳-实体有限元模型补充分析了结合段长度、前承压板、剪力连接件等参数的影响。研究结果表明:构造简化后的某双边箱铁路混合梁斜拉桥钢-混结合段缩尺模型在轴压、最大正/负弯矩工况作用下,所有测点的荷载-应力曲线均呈现出良好的线性相关性,钢-混结合段受力仍处于弹性阶段;钢混界面滑移测点的荷载-滑移关系近似为线性变化,滑移量最大值为0.15 mm,且卸载后残余滑移可忽略,钢板和混凝土协同受力良好;轴压工况下钢混界面剪力呈现出“两端大、中间小”马蹄形分布特征,结合段长度越大,界面剪力及相对滑移越小;结合段长度超过2倍剪力传递长度时,钢梁和混凝土梁之间区域剪力和相对滑移量几乎为0;后承压板、前承压板、钢梁埋入段分别约承担56.0%、12.4%、11.0%的轴力,前承压板、钢梁埋入段不改变钢-混结合段钢结构和混凝土正应力变化趋势、轴力分布特征,对钢-混结合段应力和传力改善作用不明显;横隔板可改善后承压板与钢顶底板处应力集中。
To study the force performance and force transfer mechanism of railway double-box hybrid girder cable-stayed bridge and optimize its construction form and size,the front pressure plate,steel beam embedded section,and steel compartment in the preliminary design of the real bridge were canceled,and the density of the shear connector was minimized.A test model with a scale ratio of 1:2.5 was then designed and constructed for the steel-concrete sections.The stress distribution,bearing performance,and shear transfer characteristics of the combined section were analyzed under calculation conditions of each real bridge design.The shell-solid finite element model was built to further analyze parameters including the effect of the combined section length,front pressure plate,and shear connector.Research results show that with the simplified structure,the scale model of the railway double-box hybrid girder cable-stayed bridge has seen a good linear correlation in the load-stress curve of all the measuring points under the influence of axial pressure and maximum positive/negative bending moment.The force of the steel-concrete joint section is still in the elastic stage.The load-slip relationship of the slip measuring point of the steel-concrete interface is approximately linear change,with a maximum slip value of o.15 mm.The residual slip upon unloading can be ignored.There is also a cooperative force between the steel plate and concrete.Under the axial pressure condition,the shear force of the steelconcrete joint interface shows a horseshoe-shaped distribution featuring large ends and small middle.The larger the combined section length,the smaller the interface shear and relative slip.When the combined section length exceeds 2 times of the shear transfer length,the regional shear force and relative slip between the steel beam and the concrete beam are almost zero.The rear pressure plate,front pressure plate,and steel beam embedded section bear about 56.0%,12.4%,and 11.0%axial force,respectively.The front pressure plate and steel beam do not change the positive stress change trend and axial force distribution characteristics of the steel structure and concrete in the steel-concrete section.No significant effect can be seen on the stress and force transfer of the steel-concrete section.The stress concentration at the rear pressure plate and the steel roof and bottom plate can be improved by the transverse partition plate.
作者
康炜
李伟
文强
程高
房帅平
孟祥建
刘永健
文博华
KANG Wei;LI Wei;WEN Qiang;CHENG Gao;FANG Shuai-ping;MENG Xiang-jian;LIU Yong-jian;WEN Bo-hua(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,Shaanxi,China;School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;China Railway Bridge and Tunnel Technologies Co.,Ltd.,Nanjing 210061,Jiangsu,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China)
出处
《交通运输工程学报》
北大核心
2025年第3期114-129,共16页
Journal of Traffic and Transportation Engineering
基金
国家自然科学基金项目(52478126)
陕西省秦创原“科学家+工程师”队伍建设项目(2022KXJ-036)
陕西省重点研发计划(2024GX-ZDCYL-03-09)
中铁第一勘察设计院集团有限公司科技研发项目(院科(川藏)20-12)
陕西省交通运输厅交通运输科研项目(23-20X)。
关键词
桥梁工程
混合梁斜拉桥
模型试验
钢-混结合段
传力机理
剪力传力长度
bridge engineering
hybrid girder cable-stayed bridge
model test
steel-concrete section
force transfer mechanism
shear force transfer length
