大跨度钢管混凝土系杆拱桥的静动力研究及关键节点应力分析

发布时间：2018-01-04 21:00

本文关键词：大跨度钢管混凝土系杆拱桥的静动力研究及关键节点应力分析　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：桥梁上部结构左右非对称的布置形式会对结构的动静力行为和地震响应产生怎样的影响,同时拱脚节点的具体受力和破坏情况,都是桥梁工作者十分关注的问题。本文以某在建钢管混凝土系杆拱桥为工程背景,针对其上部结构左右非对称的布置特点,建立全桥模型,对其进行动静力分析和弹性分析,并对拱脚的受力和破坏做了重点分析。本文的主要研究内容如下:(1)使用Midas Civil建立全桥模型,并对其做静力分析,得到了桥梁模型在五种工况下的内力和位移分布情况。结果表明:拱肋处于全截面受压状态,系梁上各部位受力相对较小且均匀,都在规定容许的范围内;恒载对结构内力的影响最大,可占组合荷载总效应的70%～85%;桥梁上部结构左右非对称的布置形式,对结构的受力分布有较大影响,但左右两侧位移基本相同,线性基本不受影响。(2)使用ANSYS软件建立拱脚结构的实体有限元模型,模拟了其在弯矩最大工况下和轴力最大工况下的应力分布状况,同时结合强度破坏理论,找出了最有可能产生破坏的位置。结果表明:拱脚总体处于受压状态,且应力分布较为均匀,满足设计要求;在变截面处,出现了应力集中现象,且上述位置也是拱脚结构最有可能产生破坏的部位;拉应力主要出现在拱肋支架拆除阶段即拱肋弯矩最大时,在运营阶段,即轴力最大工况下,拱脚总体受力合理,应力始终满足规范要求。(3)使用Midas Civil对全桥模型做动力分析,研究其动力特性,结果表明:在桥梁的自振响应中,拱肋的振动变形最大,其横向刚度和稳定性都最差的,竖向的累积振型参与质量最小;竖向整体刚度最大,横向整体刚度最小,纵向整体刚度居中;同时桥梁结构左右非对称布置,对桥梁的动力响应产生了的影响。(4)使用Midas Civil采用反应谱法对全桥模型做弹性分析,模拟了其在纵向、横向、竖向、纵向+横向、纵向+竖向和横向+竖向六种工况下的地震响应。结果表明:对地震波进行组合输入在抗震分析中是必要的;拱肋横向刚度相对较小,其面外稳定是抗震的薄弱环节;当竖向和纵向组合输入时,纵向抗震最不利,当横向和纵向组合输入时,横向抗震最不利;桥梁上部结构的左右非对称布置,主要对拱肋和桥墩的受力产生影响,对桥梁的整体稳定产生不利影响,但对拱肋和桥墩的位移变形影响不大。本文对桥梁左右非对称布置下的分析结果可为今后相似桥梁的设计提供参考。
[Abstract]:The bridge superstructure layout about asymmetric structure on the static and dynamic behavior and seismic response to the effect of concrete, stress and damage the arch foot node, is a bridge worker pays close attention to the problem. In this paper in the construction of steel tube concrete arch bridge as the engineering background, arranged according to the characteristics of the upper asymmetrical structure, establish the model of the whole bridge, the analysis of static analysis and elasticity, and the arch foot stress and damage is analyzed. The main research contents of this paper are as follows: (1) using Midas Civil to establish the model of the whole bridge, and the static analysis, obtained the bridge the model in five conditions of the internal force and displacement distribution. The results showed that: in the total cross section of arch rib beam on compression, each part of force is relatively small and uniform, are within allowable range; constant load on the internal force of the structure The biggest impact load can be accounted for by the combination of the total effect of 70% ~ 85%; layout of bridge superstructure asymmetrical, the structure has a great influence on the stress distribution of the left and right sides, but basically the same basic linear displacement, is not affected. (2) the establishment of arch foot structure finite element model using ANSYS software, simulation the maximum bending moment and axial force under the condition of the maximum under the condition of stress distribution, combined with the strength theory, find out the most possible damage position. The results show that the arch foot in the overall state of compression, and the stress distribution is uniform, meet the design requirements; in cross-section, the the phenomenon of stress concentration, and the location is also the arch structure is most likely to produce destructive parts; tensile stress occurs mainly in arch rib arch rib support removal stage is the maximum bending moment, axial force in the operation stage, namely the overall condition of arch foot Reasonable stress, stress always satisfy the standard requirement. (3) using Midas Civil to do dynamic analysis of the whole bridge model to study the dynamic characteristics, the results showed that: in the bridge vibration response, the maximum deformation vibration of arch rib, the lateral stiffness and stability are the worst, the cumulative vertical vibration type participate in the quality of the minimum; vertical stiffness, lateral stiffness of the overall minimum longitudinal stiffness of bridge structure around the middle; at the same time, non symmetrical layout, influence the bridge dynamic response produced. (4) the use of Midas Civil by using the response spectrum method of elastic analysis of the whole bridge model, simulate the longitudinal horizontal, vertical, longitudinal and transverse, longitudinal and vertical, and horizontal and vertical seismic response under six different conditions. The results show that the combination of input in seismic analysis is necessary for the seismic wave; arch rib lateral stiffness is relatively small, the out of plane stability is a weak link in the earthquake; When the vertical and longitudinal combination of input, the most unfavorable longitudinal seismic, horizontal and vertical combination as input, the most unfavorable transverse earthquake; bridge superstructure asymmetrical arrangement of main arch rib and bridge pier impact force, adversely affect the overall stability of the bridge, but the displacement of the arch rib and pier the deformation has little effect on the bridge. This paper analysis about non symmetrical arrangement of the results can provide a reference for the future design of similar bridges.

【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.22

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