摘要
为了解斜拉桥悬臂施工阶段,斜拉索索力作用下主梁的应力分布规律,结合圣维南原理,以宽幅混凝土主梁斜拉桥常用的3种主梁为研究对象(Π形实体边主梁、PK箱形主梁以及箱形中央索面主梁)。采用仿真计算方法,对合龙前最大悬臂施工阶段下,悬臂端索力对主梁的空间受力状态进行分析,归纳出不同形式主梁混凝土斜拉桥应力分布特点。结果显示:主梁应力分布的顺桥向影响范围均近似为1个梁宽,索力对不同形式主梁的传递角度均可取26°;建议大跨度宽幅斜拉桥采用PK箱形;对于中央索面斜拉桥主梁翼缘可以滞后1～2个节段浇筑,降低翼缘的剪力滞效应,提高施工效率。
To examine the stress distribution law of main girder under the action of stay cable forces during the cantilever construction stage of the cable-stayed bridge,following the Saint-Venant′s principle,the three types of main girders that are commonly used in the cable-stayed bridge with wide concrete main girder are taken as the study objective,including theΠ-shaped solid edge girders,PK box girder and box girder carrying central cable plane.The simulation calculation method was used to analyze the effect of cantilever-end cable forces on the spatial load bearing condition of the main girder,in the maximum cantilever construction stage before closure.And the stress distribution characteristics of cable-stayed bridges with different concrete main girders were summarized.The results show that the influential area of main girder stress distribution along the bridge length covers about the width of the a girder,to different types of main girders,the cable force transmitting angle can all be set at 26°.It is suggested that PK box girder be chosen for the long-span cable-stayed bridge with wide deck.For the cable-stayed bridge with central cable plane,the casting of flanges of the main girder can be laid one or two sections behind,so as to reduce the shear lag effect in the flanges and improve construction efficiency.
作者
黄辉
亢鑫
涂满明
HUANG Hui;KANG Xin;TU Man-ming(Design Company,China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China)
出处
《世界桥梁》
北大核心
2018年第6期46-50,共5页
World Bridges
关键词
斜拉桥
混凝土梁
斜拉索
索力
悬臂施工
受力特性
传递角度
有限元法
cable-stayed bridge
concrete girder
stay cable
cable force
cantilever construction
load bearing property
transmitting angle
finite element method
