摘要
目前关于横隔梁对波形钢腹板PC连续梁桥纵向正应力的影响,都是基于小梁试验或理论分析的基础,与实际有差别。鉴于此,依托一在建单箱九室波形钢腹板PC组合连续箱梁桥,建立该桥有限元模型,分析3车道偏载作用下有无横隔梁2个工况下箱梁顶、底板的纵向正应力分布规律和剪力滞效应。结果表明:未设横隔梁的桥梁纵向正应力分布变化剧烈,距墩顶越近,顶、底板正应力横向分布变化越大;设置横隔梁后桥梁纵向正应力分布较为均匀,顶、底板正应力横向分布在跨中截面附近变化较大;未设横隔梁与设置横隔梁时顶、底板正应力最大比值分别为1.47、1.32;设置横隔梁的桥梁在汽车荷载下剪力滞效应最大,3车道偏载与6车道对称荷载作用下箱梁顶板剪力滞系数比值为1.04,底板剪力滞系数比值为1.06;横隔梁对改善箱梁正应力分布、降低剪力滞程度具有显著影响。
Currently ,the influence of diaphragms on longitudinal normal stress of PC continu‐ous girder bridge with corrugated steel webs is examined on the basis of small beam tests and theo‐retical analysis ,which is possibly different from the actual condition .For this reason ,a nine‐cell single box PC composite continuous girder bridge under construction was taken as the study back‐ground .The finite element models of the bridge ,with and without diaphragms respectively ,were established to analyze the distribution law of longitudinal normal stress and shear lag effect in the top and bottom slabs under the action of 3 lanes of eccentric loads .The results of the study indi‐cate under the condition that no diaphragms are installed ,the longitudinal normal stress distribu‐tion show s violent variation ,the transverse distribution of normal stress in the top and base slabs exhibits greater variation as closer to the pier top .But w hen diaphragms are installed ,the longitu‐dinal normal stress distributes more uniformly ,substantial transverse distribution variation of the normal stress in the top and base slabs was found near the midspan cross section .The maximum ratio of the normal stress in the top and bottom slabs when the diaphragms are not installed is 1 .47 ,and 1 .32 when the diaphragms are installed .The bridge with diaphragms generates maxi‐mum shear lag effect under traffic loads .T he shear lag coefficient ratio of top slab shears under the action of 3 lanes of eccentric loads and 6 lanes of symmetrical loads is 1 .04 ,w hereas that of the base slab is 1 .06 .Diaphragms have significant effects on the improvement of the box girder normal stress distribution and the reduction of shear lag effect .
出处
《世界桥梁》
北大核心
2015年第1期65-69,共5页
World Bridges
基金
国家自然科学基金项目(50078014)
江苏省高校自然科学基金项目(14KJB560002)
关键词
连续梁
组合箱梁
宽桥面
横隔梁
波形钢腹板
正应力
剪力滞
有限元法
continuous girder
composite box girder
wide bridge deck
diaphragm
corruga-ted steel web
normal stress
shear lag
finite element method
