斜拉桥钢拱塔—砼墩结合段受力分析及设计参数优化研究

发布时间：2018-01-03 20:25

本文关键词：斜拉桥钢拱塔—砼墩结合段受力分析及设计参数优化研究　出处：《长安大学》2016年硕士论文　论文类型：学位论文

【摘要】：双拱塔异型斜拉桥结构独特,其空间及受力性能有异于常规斜拉桥,特别是钢拱塔-混凝土墩结构在斜拉桥上的应用加大了其复杂程度,该部位是塔身到基础整个结构的刚度突变点,此处往往是结构受力的薄弱点;目前对该结构关键部位-剪力键的研究偏少,其受力机理尚不明确、计算理论尚未成熟;剪力键形式不同对应的承载能力计算公式各异,不利于生产应用。本文依托西安双拱塔异型斜拉桥,运用有限元分析软件,对该桥钢拱塔-砼墩结合段剪力键变设计参数下受力计算,并对结合段剪力键设计参数进行优化;借鉴相关模型试验数据对剪力键承载能力公式展开研究,探索合理统一的剪力键承载能力计算公式。首先论述钢塔结合段发展、应用概况及研究背景,描述其连接形式、实例布置,并以此为基础提出结合段存在的问题,对结合段最重要的构件-剪力键进行探讨,剪力键的运用使得弹性模量差别较大的钢结构和混凝土结构形成统一整体、协同作用,防止两者界面间出现水平相互滑移和分离。其次运用有限元软件对桥梁结构进行整体结构验算,在最不利受力组合基础上对结合段独立进行局部受力分析,逐一改变混凝土强度等级、塔内混凝土高度和钢板厚度、钢板开孔孔径及间距五个设计参数,分析各变参数下局部受力,优化结构设计。最后,借鉴相关模型试验数据,运用有限元对结合段重要构件PBL和焊钉剪力键模型进行材料非线性分析,得出各自极限承载力,综合模型试验、有限元模拟两种分析结果对剪力构件的承载力公式进行整合修正,调整修正系数,推出物理意义明确的承载力统一计算公式,为剪力键的设计安全提供理论参考。
[Abstract]:The special structure of double-arch tower cable-stayed bridge is unique, and its space and mechanical performance are different from that of conventional cable-stayed bridge, especially the application of steel arch tower and concrete pier structure in cable-stayed bridge has increased its complexity. This part is the abrupt point of stiffness of the whole structure from the tower to the foundation, which is often the weakness of the structural force. At present, the research on the key part of the structure, the shear bond, is less, the mechanism of the stress is not clear, and the calculation theory is not mature. The calculation formulas of the bearing capacity of different shear bond forms are different, which is not conducive to the application of production. This paper relies on Xi'an double-arch tower special-shaped cable-stayed bridge, using finite element analysis software. Under the shear bond variable design parameters of the steel arch tower and concrete pier of the bridge, the design parameters of the combined shear key are optimized. Based on the relevant model test data, this paper studies the formula of shear bond bearing capacity, and explores a reasonable and unified calculation formula of shear key bearing capacity. Firstly, the development, application and research background of steel tower joint section are discussed. The paper describes its connection form, case arrangement, and puts forward the problems existing in the joint segment on the basis of it, and probes into the most important component of the joint section, the shear key. The application of shear bond makes the steel structure and concrete structure with different elastic modulus form a unified whole and cooperate with each other. To prevent horizontal slip and separation between the two interfaces. Secondly, the finite element software is used to check the overall structure of the bridge structure, and on the basis of the most unfavorable combination of forces, the local force analysis of the joint section is carried out independently. Changing the strength grade of concrete one by one, the height of concrete in tower and thickness of steel plate, the hole aperture and spacing of steel plate are changed one by one, the local force under each variable parameter is analyzed, and the structural design is optimized. Based on the relevant model test data, the material nonlinear analysis of PBL and welded nail shear bond model is carried out by using finite element method, and the ultimate bearing capacity of each member is obtained, and the comprehensive model test is carried out. The two results of finite element simulation can integrate and modify the formula of bearing capacity of shear members, adjust the correction coefficient, and deduce the unified calculation formula of bearing capacity with clear physical meaning. It provides a theoretical reference for the design safety of shear key.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U448.27

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