单箱三室宽箱梁斜腹板倾斜角度优化及预应力效应分析

发布时间：2018-03-21 10:49

本文选题：宽箱梁　切入点：单箱三室　出处：《兰州交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着交通科技的发展，宽跨比较大的箱形梁应用的越来越广泛，合理的截面形式及空间预应力束布置对宽箱梁的力学性能有着重要的影响。对于预应力混凝土宽箱梁结构，在主梁自重、二期恒载、预应力、温度效应及车辆等荷载的作用下，梁体横向空间效应非常显著，传统的梁单元分析方法已不能准确地分析出宽体箱梁横向应力的分布情况，该方法对结构横向的受力分析主要利用横向框架分析模块，其计算结果精确度较低，无法保证宽箱梁结构的局部受力安全。因此，在设计该类桥梁时，必须充分考虑主梁的空间效应，合理布置普通钢筋和预应力束，确保桥梁结构在施工阶段及成桥运营阶段的安全。本论文主要完成的工作如下： 1、本文首先介绍了箱形截面的结构特点及受力特点，并对宽箱梁空间受力状态及预应力钢束布置的研究现状做出了总结。阐述了几种常用的分析宽箱梁桥受力特性的方法，根据实际工程中存在的问题和不足，诠释了对宽箱梁进行深入研究的意义。 2、本文以南京地铁三号线高架区间交叉渡线区3×30m连续宽箱梁桥为工程背景，应用空间有限元程序Midas/FEA，，对全桥单箱三室箱形主梁建立了三维有限元模型进行空间应力分析，通过对比分析总结了此类宽箱梁桥的空间应力分布特点及规律，找出了该桥受力较为不利的部位。 3、在原结构有限元分析模型的基础上，通过变化斜腹板倾斜角度等参数，对比分析了不同工况下主梁应力的变化情况，得出了适合本桥箱形主梁的斜腹板倾斜角度。 4、对宽箱梁结构的预应力效应进行了分析，分析纵向预应力束不同配筋方式以及配置横向预应力束前后对宽箱梁的应力状态及结构变形的影响，最后总结出了较为合理的预应力体系。通过上述分析，明确了单箱三室宽箱梁结构的空间应力状态，找出了较为合理的截面形式和预应力体系。希望本研究结果能为以后同类桥梁的设计提供参考。
[Abstract]:With the development of transportation technology, box beam with wide span is more and more widely used. Reasonable section form and spatial prestressing beam arrangement have important influence on the mechanical properties of wide box girder. Under the influence of deadweight, dead load, prestress, temperature effect and vehicle load, the transverse spatial effect of beam body is very significant. The traditional method of beam element analysis can not accurately analyze the distribution of transverse stress of wide box girder. This method mainly uses the transverse frame analysis module to analyze the transverse force of the structure. The accuracy of the calculation results is low and the local force safety of the wide box girder structure can not be guaranteed. Therefore, in the design of this kind of bridge, The space effect of the main beam must be fully considered, the normal steel bar and prestressing beam should be arranged reasonably to ensure the safety of the bridge structure in the construction stage and the operation stage of the bridge. The main work accomplished in this paper is as follows:. 1. Firstly, this paper introduces the structural characteristics and stress characteristics of box section, summarizes the research status of space stress state of wide box girder and the arrangement of prestressed steel beam, and expounds several common methods to analyze the stress characteristics of wide box girder bridge. According to the existing problems and shortcomings in practical engineering, the significance of deep research on wide box girder is explained. 2. Taking the 3 脳 30m continuous wide box girder bridge in the crossing crossing section of Nanjing Metro Line 3 as the engineering background, the three-dimensional finite element model of the single box and three chamber box girder of the whole bridge is established by using the space finite element program Midas / FEAA. The spatial stress distribution characteristics and rules of this kind of wide box girder bridge are summarized by comparison and analysis, and the unfavorable position of the bridge is found out. 3. On the basis of the finite element analysis model of the original structure, the stress variation of the main beam under different working conditions is compared and analyzed by changing the inclined web angle and other parameters, and the inclined web angle suitable for the box girder of the bridge is obtained. 4. The prestress effect of wide box girder structure is analyzed, and the influence of different reinforcement ways of longitudinal prestressing beam and the influence of transverse prestressing beam on the stress state and structural deformation of wide box girder is analyzed. Finally, the reasonable prestressing system is summarized. Through the above analysis, the spatial stress state of the single box and three chambers wide box girder structure is determined, and a more reasonable section form and prestressing system are found. It is hoped that the results of this study can be used as a reference for the design of similar bridges in the future.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.213

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