摘要
为研究斜拉桥悬臂施工状态下PK钢箱叠合梁引起的纵桥向正应力沿横向截面分布不均匀的特性,依托银洲湖特大斜拉桥工程实例,利用ANSYS软件建立PK钢箱叠合梁跨中梁段空间有限元模型,考虑了长悬臂状态下不同悬臂施工长度以及最大悬臂和合拢阶段的典型荷载工况,采用有限元法研究PK钢箱叠合梁斜拉索锚固截面和斜拉索中间截面的剪力滞效应。通过与实测值的比较验证了有限元模型的准确性,并计算分析得出在不同荷载工况下PK钢箱叠合梁混凝土顶板与钢箱梁底板的纵向正应力分布变化规律及剪力滞系数。研究结果表明:在悬臂施工阶段不同悬臂长度下,PK钢箱叠合梁混凝土顶板和钢箱底板的轴向正应力和剪力滞系数沿横向分布规律存在差异,截面会同时出现正、负剪力滞效应;混凝土顶板和钢箱底板在外腹板处的负剪力滞效应较为明显;斜拉索锚固截面的剪力滞效应比斜拉索中间截面的更为突出,PK钢箱叠合梁锚固截面的应力分布更应引起重视。
In order to investigate the uneven distribution characteristics of longitudinal normal stress along the transverse section caused by PK steel box composite beam during cantilever construction of cable-stayed bridge,based on the engineering example of the Yinzhouhu Extra-large Cable-stayed Bridge,a finite element model of mid-span beam section of the PK steel box composite beam was established using ANSYS software.Different cantilever lengths under long cantilever construction and typical load conditions during maximum cantilever and closure stages were considered.Finite element method was used to study the shear lag effect of the cable-stayed anchoring section of the PK steel box composite beam and the middle section of the cable.The accuracy of the finite element model was verified by comparing with measured values.The longitudinal normal stress distribution and shear lag coefficient of the concrete top plate and the steel box bottom plate of the PK steel box composite beam under different load conditions were calculated and analyzed.The results show that under different cantilever lengths during the cantilever construction phase,there are differences in the axial normal stress and shear lag coefficient distribution laws of the concrete top plate and the steel box bottom plate of the PK steel box composite beam along the transverse direction,and positive and negative shear lag effects occur simultaneously at the cross section.The negative shear lag effect of the concrete top plate and the steel box bottom plate is more obvious at the outer flange.The shear lag effect of the cable anchorage section is more prominent than that of the middle section of the cable,and the stress distribution of the PK steel box composite beam anchorage section should be given more attention.
作者
张玉平
张超
ZHANG Yuping;ZHANG Chao(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China)
出处
《建筑结构》
北大核心
2023年第S01期1929-1936,共8页
Building Structure
基金
国家自然科学基金资助项目(52078059)
中电建路桥集团有限公司科技项目(LOKY2016-02)
关键词
斜拉桥
PK钢箱叠合梁
悬臂施工
剪力滞效应
有限元分析
cable-stayed bridge
PK steel box composite beam
cantilever construction
shear lag effect
finite element analysis
