T形交叉口异形钢箱梁空间受力分析  

Analysis on Spatial Stress of Irregular Steel Box Girder at T-intersection

作　　者：丁伟亮 DING Weiliang

机构地区：[1]广东省建筑设计研究院有限公司,广东广州510010

出　　处：《城市道桥与防洪》2024年第10期88-90,M0010,共4页Urban Roads Bridges & Flood Control

摘　　要：由于交通功能的要求和地形条件的限制,在市政道路的立体交叉口常设置异形钢箱梁桥。钢箱梁异形结构具有明显的空间特性,受力情况十分复杂。为了较为全面地反映该结构的空间受力特性,以广州市某垃圾处理厂公用配套工程为研究实例,针对T形交叉口异形钢箱梁结构,采用三维板壳单元建立有限元模型进行结构受力分析和计算。结果表明:在进行T形交叉口竖向设计时,为减少结构设计和施工时的困难,应尽量减小交叉口处结构的纵横向坡度;在最不利工况基本组合下,异形钢箱梁顶底板最大应力均位于支座附近,出现了局部应力集中效应,设计时应对支座范围内的顶底板钢板进行适当加强,并设置支座加劲肋;桥梁支反力不均匀现象比较明显,部分支座甚至会出现负反力,易引起支座脱空现象,需设置抗拉球形支座或设置压重。所得结果可为其他类似桥梁结构的设计和计算提供可借鉴的经验。Due to the requirements of transportation functions and the limitations of terrain conditions,the irregular steel box girder bridges are often installed at the intersections of municipal roads.The irregular structure of steel box girder has the obvious spatial characteristics and complex stress conditions.In order to comprehensively reflect the spatial stress characteristics of the structure,taking a public supporting project of a waste treatment plant in Guangzhou as a research example,aiming at the irregular steel box girder structure at T-intersection,the 3D plate shell element is used to establish the finite element model for the analysis and calculation of structural stress.The results indicate that in the vertical design of T-intersection,in order to reduce the difficulties in structural design and construction,the longitudinal and transverse slopes of the structure at the intersections should be minimized as much as possible.Under the basic combination of the most unfavorable working conditions,the maximum stress on the top and bottom plates of irregular steel box girder is located near the support,and the local stress concentration effect appears.During the design,the steel plates of the top and bottom plates within the support range should be appropriately strengthened,and the support stiffening ribs should be set up.The uneven phenomenon of bridge support reaction force is quite obvious,and some supports may even experience the negative reaction force,which can easily cause support separation.It is necessary to set up the tensile ball supports or the weights.The obtained results can provide valuable experience for the design and calculation of other similar bridge structures.

关 键 词：T形交叉口 异形钢箱梁 板单元 空间受力分析 

分 类 号：U441[建筑科学—桥梁与隧道工程]