上承提篮式拱桥的稳定性及自振特性分析

发布时间：2018-09-10 09:31

【摘要】：在我国的公路建设和铁路建设中,拱桥是一种常用的桥梁结构形式。拱桥与其他形式桥梁相比而言,具有不仅在结构形式上的不同,而且在结构本身的受力性能上也有着本质性的差别。对于现在的桥梁工程研究领域内,越来越突显桥梁自身的稳定性问题。上承式拱桥往往集于拱圈、立柱、桥面板一身,使得拱桥的结构集为一体充分的发挥最大承载能力,稳定性的能力也逐渐提高,因此研究上承式拱桥的稳定性问题对于实际工程具有很重要的意义。本文采用以建铁路单线北盘江上承提篮式拱桥为研究背景,应用Midas/Civil有限元软件,建立不同种荷载工况,考虑对该桥分析稳定性问题、振动特性,总结规律,并给以后的设计及施工提供些意见以供参考。具体进行以下几个主要方面的工作:(1)通过施工阶段,对拱上最高的刚架立柱进行了线性和几何非线性的分析,考虑几何非线性稳定,得出的临界荷载值要小于线性稳定的临界荷载值,说明该桥的几何非线性是起到关键性作用。(2)通过成桥阶段,整体桥梁在不同荷载工况作用下,考虑屈曲分析,几何非线性的稳定特征值要低于线性的稳定特征值,分析不同失稳模态图,对比不同工况,桥梁的倾斜规律。(3)根据大量失稳工程事件分析,得出一些关于在设计方面、施工建造及规范要求,提出一些自己的看法。分别从不同的设计参数,施工的工艺及技术方面提出一些优化稳定性措施的构想。(4)分析该桥的自振特性,对比分析由振动影响的不同因素造成对整体桥梁频率值的变化规律。
[Abstract]:Arch bridge is a commonly used bridge structure in highway construction and railway construction in China. Compared with other kinds of bridges, arch bridges are not only different in structure form, but also have essential difference in the mechanical performance of the structure itself. In the field of bridge engineering, the stability of bridges is becoming more and more important. The upper bearing arch bridge is often integrated in the arch ring, column and deck, which makes the structure of the arch bridge fully exert the maximum bearing capacity, and the stability ability is gradually improved. Therefore, it is very important for practical engineering to study the stability of overbearing arch bridge. In this paper, based on the research background of the single-track Beipanjiang overhead arch bridge, using Midas/Civil finite element software to establish different load conditions, considering the stability problem, vibration characteristics, summing up the rules of the bridge. And to the future design and construction to provide some advice for reference. The main works are as follows: (1) through the construction stage, the linear and geometric nonlinear analysis of the highest rigid frame column on the arch is carried out, and the geometric nonlinear stability is considered. The critical load value obtained is smaller than the linear stable critical load value, which shows that the geometric nonlinearity of the bridge plays a key role. (2) through the completion stage, the buckling analysis of the whole bridge under different load conditions is considered. The stability eigenvalues of geometric nonlinearity are lower than those of linear ones. Different instability mode diagrams are analyzed, and the slope laws of bridges under different working conditions are compared. (3) based on the analysis of a large number of unstable engineering events, some problems in design are obtained. Construction and specification requirements, put forward some of their own views. From different design parameters, construction technology and technology, the paper puts forward some optimal stability measures. (4) the natural vibration characteristics of the bridge are analyzed, and the variation law of frequency value of the whole bridge caused by different factors affected by vibration is comparatively analyzed.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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