宽幅预应力混凝土斜拉桥施工阶段剪力滞分析  

Analysis of Shear Lag Effect in Construction Process of Broad Prestressed Concrete Cable-Stayed Bridge

作　　者：张华兵[1,2] 郭翠翠[1,2] 

机构地区：[1]中铁大桥局集团桥科院有限公司,湖北武汉430034 [2]桥梁结构安全与健康湖北省重点实验室,湖北武汉430034

出　　处：《世界桥梁》2014年第3期71-75,共5页World Bridges

摘　　要：武汉市金桥为(138+81+41)m的独塔双索面预应力混凝土斜拉桥,主梁采用变宽分离式双边箱截面,最宽处宽49.899m,主跨和边跨分别采用悬臂浇筑和支架浇筑法施工。为了解主梁横截面各位置应力的分布规律,指导该桥施工监控,采用ANSYS建立实体模型,模拟主梁的施工过程,对MB6节段施工过程中各工况下MB2和MB3节段前端截面的顶、底板的剪力滞效应进行分析。结果表明:该桥主梁较宽,剪力滞效应比较明显,其中顶板的剪力滞效应相对于底板更加明显;预应力对截面剪力滞的影响有限,但近塔端越接近预应力作用范围的区域截面剪力滞受到预应力的影响越大;集中荷载对剪力滞效应影响较大。The Jinqiao Bridge in Wuhan is a single pylon prestressed concrete cable-stayed bridge with span arrangement of （138 ＋ 81 ＋ 41） m and with double cable planes .The main girder adopts the separated double-side box cross section with variable width and the widest part is 49 .899 m .The main span is constructed by the cantilever cast method ,while the side spans are cast on scaffoldings .In order to examine the law of stress distribution at different locations of the main girder cross section and to guide the construction control and monitoring of the bridge ,the ANSYS was used to set up the full-scale model of the bridge to simulate the construction process of the main girder ,and analyze the shear lag effect in the top and bottom plates of the front section of the MB3 and MB2 segments under different load cases during the construction process of the MB6 segment .The results shows that the girder of the bridge is broad and the shear lag effect is dis -tinct ,and the shear lag effect in the top plate is much more noticeable than that in the bottom plate ,the prestress has very limited effect on the shear lag effect of the cross section ,the prestress shows more significant effect on the cross section shear lag effect in the vicinity of the prestress acting zone near the pylon . And concentrated load also has greater influence on the shear lag effect .

关 键 词：斜拉桥 预应力混凝土结构 宽主梁 分离式双边箱截面 悬臂浇筑 剪力滞 集中荷载 有限元法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U441.5[交通运输工程—道路与铁道工程]