摘要
丹江口水库特大桥为主跨760 m的双塔部分地锚式混合梁斜拉桥,主梁钢-混结合段设置在主跨侧距桥塔中心线20 m处,总长6 m,采用多格室后承压板式构造,由后承压板、钢格室和预应力钢绞线等组成。为验证大桥钢-混结合段构造设计的合理性,明确钢-混结合段的受力性能及传力特征,采用ANSYS软件建立钢-混结合段有限元模型,分析承载能力极限状态轴力最不利荷载组合下钢-混结合段钢格室、承压板、格室填充混凝土、开孔板剪力键等主要部件的受力,以及主要传力构件的传力比。结果表明:钢-混结合段总体应力分布均匀,各构件受力指标均满足设计要求,钢-混结合段刚度过渡均匀,传力平顺,有效避免了刚度突变导致的应力集中;钢-混结合段剪力传递以边箱格室剪力键为主,顺桥向随格室填充混凝土与开孔板相对滑移累积,开孔板剪力键剪力逐渐增大;承压板承压传递与钢格室承剪传递轴力比例相当。该桥采用的多格室后承压板式构造,实现了承压板与钢格室承压传剪协同作用,改善了钢-混结合段的受力性能。
With a main span of 760 m,the Danjiangkou Reservoir Bridge is a two-pylon,hybrid girder cable-stayed bridge,featuring the pairs of earth-anchored stay cables.The two steel-concrete joint sections in the superstructure,each measuring 6 m in total length and consisting of rear bearing plates,a latticed steel chamber and prestressing tendons,are located within the main span,20 m to the centerlines of the two pylons.The steel-concrete joint section was numerically simulated in ANSYS,to verify the effectiveness of the structural design and figure out the load bearing behavior and load transfer characteristics of these specific locations.The load bearing conditions of the primary load transfer components under the most unfavorable axial load combinations in ultimate limit state,including the steel beams,bearing plate,in-fill concrete in the steel chamber,and PBL connectors,were analyzed,and the load-transfer sharing portions of these primary components were calculated.The results demonstrate that the steel-concrete joint section is in uniform stress distribution state,with required load bearing indexes for each component.The steel-concrete joint section displays even rigidity transition and smooth load transfer,effectively preventing the occurrence of stress concentration triggered by abrupt rigidity change.The shear connectors in the edge cells of the steel-concrete joint section play a dominant role in shear force transfer,as the relative slips between the in-fill concrete and PBL connectors accumulate,the shear forces of the PBL connectors gradually increase.The axial ratio of the pressure transfer of bearing plates roughly equates the axial ratio of the shear force transfer of the latticed chamber.The pressure transfer of bearing plates collaborate with the shear force transfer of the latticed steel chamber,leading to the improved load bearing capacity of the steel-concrete joint section.
作者
阳晏
覃作伟
廖原
陶辰亮
YANG Yan;QIN Zuowei;LIAO Yuan;TAO Chenliang(School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430061,China;Hubei Communications Planning and Design Institute Co.,Ltd.,Wuhan 430050,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2024年第4期93-98,共6页
Bridge Construction
基金
湖北省交通运输厅科技项目(2020-2-2-1)。
关键词
斜拉桥
混合梁
钢-混结合段
多格室构造
开孔板剪力键
受力分析
有限元法
cable-stayed bridge
hybrid girder
steel-concrete joint section
latticed steel chamber
PBL connector
mechanical property analysis
finite element method
