超宽箱梁多种支承条件下横梁结构受力研究

发布时间：2018-02-26 20:09

本文关键词： 超宽箱梁空间受力梁格法有效宽度　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国城市交通建设事业的发展,城市桥梁的修建数量日益增加,对桥型、构造都提出了新的要求,超宽箱梁应运而生。超宽箱梁因其横向扭转刚度较大、施工工艺简单等优点而倍受青睐。横梁是桥梁结构的重要构件,由于超宽箱梁截面宽度大,使得横梁受力更趋复杂。实际工程中,常需对其结构简化形式的可靠性与安全性进行研究验证,从而延长了设计工作周期,降低了工作效率。本文以某实际工程项目为依托,对横梁简化模型进行研究分析。首先对目前国内外的宽箱梁桥横梁受力研究成果进行总结,并介绍有限元分析方法和单元计算的一般规定。其次,以南京市纬七路西延建设工程中的M20联三跨预应力混凝土连续超宽箱梁结构为背景,分别采用梁格法与实体有限元软件对其进行受力分析,得到桥梁整体结构及横梁构件的受力情况,并对横梁结构简化模型及其计算结果进行了验证。得出了以下主要结论：(1)超宽箱梁结构空间效应显著。(2)横梁的支承情况对其挠度影响显著：支座间距较大时,横梁挠度与简支梁挠度分布规律相似,支座间距较小时,横梁挠度与悬臂梁挠度分布规律相似。(3)横梁的受力并不是由顶底板及腹板均匀分担,而是外腹板分担的荷载较小,内部腹板分担的荷载受支座间距影响较大。(4)对预应力混凝土连续箱梁结构双支座及多支座的横梁内力由横梁及两侧顶底板共同承担,表明横梁简化模型取用6倍的顶、底板厚度作为有效宽度,具有切实的实用性。(5)支承处的恒载及活载简化满足工程要求。
[Abstract]:With the development of urban traffic construction in our country, the number of urban bridges is increasing day by day. New requirements are put forward for bridge type and structure. Ultra-wide box girder emerges as the times require. The cross beam is an important component of the bridge structure. Because of the wide cross-section width of the box girder, the force of the cross beam becomes more complicated. It is often necessary to study and verify the reliability and safety of the simplified structure, thus prolonging the design cycle and reducing the working efficiency. The simplified model of cross beam is studied and analyzed. Firstly, the research results of beam force of wide box girder bridge at home and abroad are summarized, and the finite element analysis method and the general rules of element calculation are introduced. Based on the M20 three-span prestressed concrete continuous ultra-wide box girder structure in the west extension of Weiqi Road, Nanjing City, the force analysis is carried out by using the beam lattice method and the entity finite element software, respectively. The stress condition of the whole bridge structure and the cross beam member is obtained. The simplified model of cross beam structure and its calculation results are verified. The main conclusions are as follows: 1) the spatial effect of super wide box girder structure is significant. The deflection of the beam is similar to that of the simply supported beam, and the deflection of the beam is similar to that of the cantilever beam when the support spacing is small.) the force on the beam is not uniformly shared by the top and bottom plates and the web plate, but the load on the outer web plate is smaller. The load shared by the internal web plate is greatly affected by the support spacing. 4) the internal force of the prestressed concrete continuous box girder structure with double and multiple supports is shared by the cross beam and the top and bottom plates of both sides, which indicates that the simplified model of the cross beam adopts the top of 6 times. As the effective width, the thickness of the bottom plate has practical practicability. 5) the dead load and live load simplification at the support meet the engineering requirements.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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