轨道交通U型与箱型组合连续梁结构静力行为分析

发布时间：2019-03-26 16:15

【摘要】：U型箱型组合梁是槽型梁在城市轨道交通中演化出的一种新的结构形式。其具有环境友好、建筑景观适应性好和运营成本低等优点。U型箱型组合梁结构明显区别于传统的箱梁、T梁和槽型梁,对其静力行为方面的研究在国内尚处空白。本文以轨道交通(30+48+30) mU型箱型组合连续梁为工程背景,对以下几个方面进行研究:(1)采用有限元软件ABAQUS建立全桥实体单元有限元分析模型。计算和分析U型箱型组合梁整体在单项荷载和荷载组合下桥梁的结构响应。计算表明,该结构的刚度较大,双线加载工况下,跨中截面道床板整体下挠,并伴有局部下凹变形,道床板最大竖向变形和腹板转角远小于规范容许值。在结构参数影响分析中,本文重点分析了道床板板厚、桥梁宽跨比和高跨比对其受力性能的影响,研究发现U型箱型组合梁的宽跨比对梁的受力影响不大,增加道床板厚度可以增强结构的安全性,改变高跨比对梁的应力和竖向变形会产生明显影响,其中对U型梁段影响最为显著。(2)本文对桥梁局部结构的受力机理进行分析。对于U型箱型组合连续梁,道床板同时作为箱型梁的上翼缘和U型梁的下翼缘,结构受力非常复杂。且由于桥面宽度较大,会产生较为明显的剪力滞现象。本文分析了 U梁腹板的受力情况及道床板剪力滞效应的影响因素,得出结论,在U型箱型组合截面段,道床板越厚,剪力滞效应越明显,在跨中截面及在U型箱型组合截面向U型截面过渡段,由于截面形式的变化使得道床板剪力滞效应增强;在U型箱型组合截面段,随着道床板宽度的增加,道床板上表面的剪力滞现象增大,在U型截面段,道床板宽度的变化对剪力滞的影响不大。
[Abstract]:U-shaped box composite beam is a new structural form of groove beam in urban rail transit. It has the advantages of friendly environment, good adaptability of architectural landscape and low operating cost. The U-shaped box composite beam structure is obviously different from the traditional box girder, T-beam and groove beam, and the research on its static behavior is still blank in our country. In this paper, based on the engineering background of rail transit (304830) mu type composite continuous beam, the following aspects are studied: (1) the finite element analysis model of full bridge solid element is established by using the finite element software ABAQUS. The structural response of U-shaped box composite beam under single load and load combination is calculated and analyzed. The calculation shows that the stiffness of the structure is large. Under the condition of double-line loading, the overall deflection of the cross-section channel bed plate is accompanied by local concave deformation, and the maximum vertical deformation and the web rotation angle of the channel bed plate are far less than the allowable value of the code. In the influence analysis of structural parameters, the influence of slab thickness, ratio of width to span and ratio of height to span on its mechanical performance is emphatically analyzed. It is found that the width-span ratio of U-shaped box-shaped composite beam has little effect on the mechanical behavior of the beam. Increasing the thickness of the slab can enhance the safety of the structure, and changing the ratio of height to span will have an obvious effect on the stress and vertical deformation of the beam, among which the U-shaped beam has the most significant effect. (2) the mechanical mechanism of the local structure of the bridge is analyzed in this paper. For U-shaped box composite continuous beam, the track bed plate acts as both the upper flange of the box beam and the lower flange of the U-shaped beam, so the structural load is very complex. And because the width of the bridge deck is larger, the shear lag phenomenon will be more obvious. In this paper, the stress condition of U beam web plate and the influence factors of shear lag effect on U beam web plate are analyzed, and the conclusion is drawn that the thicker the pavement bed plate is, the more obvious the shear lag effect should be in the U shaped box composite section. In the middle span section and the transition section from U-shaped composite section to U-section, the shear lag effect of pavement bed plate is enhanced due to the change of cross-section form. In the U-shaped box composite section, with the increase of the width of the slab, the phenomenon of shear lag on the surface of the slab increases. In the U-section, the change of the width of the slab has little effect on the shear lag.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441

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