超大跨度轻型组合梁悬索桥的温度梯度效应研究

发布时间：2018-05-07 02:10

本文选题：超大跨度悬索桥 + 轻型组合梁　；参考：《湖南大学》2015年硕士论文

【摘要】：随着桥梁结构形式的发展以及对材料的深入研究,组合结构已经在桥梁工程中得到了广泛的应用,这种结构形式能充分发挥钢结构优越的受拉性能以及混凝土良好的受压性能。但传统组合结构中混凝土的厚度较大,随着桥梁跨径的增大,结构的自重随着增加,桥梁的跨越能力受到限制。当采用连续梁桥时可能在上部混凝土中产生较大的拉应力,使得混凝土出现裂缝,从而影响桥梁结构的耐久性能和使用性能。故在本文中的研究中提出在超大跨度悬索桥上采用轻型组合梁结构,其主要的结构形式是超高性能混凝土(UHPC)和正交异性钢桥面板通过抗剪连接件组合在一起。由于UHPC具有强度高,耐久性好,收缩徐变小,体积稳定性好的优点,将其与正交异性钢桥面板组合,可以显著降低结构的自重,提高桥梁的跨越能力。这种组合结构不仅提高了桥梁的整体受力性能,另一方面也增大了车辆轮载下正交异性板的局部受力性能。本文基于跨琼州海峡的超大跨度悬索桥实例,主要进行了以下研究工作:(1)轻型组合梁的温度梯度模拟:基于太阳辐射以及结构与外部环境之间的热传递等理论,建立了日照作用下轻型组合梁桥结构温度场分析的第三类边界条件,得出了轻型组合梁桥面板的温度梯度。同时分析了沥青铺装层对轻型组合梁温度梯度的影响,最后对影响温度梯度的主要参数进行了分析。(2)超大跨度悬索桥主缆线形计算:结合具体的工程实例,分别采用解析法编程和有限元分析计算了悬索桥在成桥状态下的主缆线形和主缆内力,对比两种计算结果可知,采用有限元进行计算是可行的,故可以采用有限元分析进行大跨度悬索桥的静力计算。(3)轻型组合梁桥在超大跨度悬索桥上的静力计算:通过有限元软件,分别采用线性二阶方法和非线性方法计算了轻型组合梁在超大跨度悬索桥上的静力性能,两种计算结果的对比表明采用计算更为简便的线性二阶方法是可行。(4)轻型组合梁与传统钢箱梁方案的比选:将原桥方案即钢箱梁上铺沥青混凝土方案与轻型组合梁方案进行受力性能和经济性的对比,计算结果表明在超大跨度悬索桥上采用轻型组合梁更具优势。
[Abstract]:With the development of bridge structure and the further study of materials, composite structure has been widely used in bridge engineering, which can give full play to the excellent tensile performance of steel structure and the good compressive performance of concrete. However, the thickness of concrete in the traditional composite structure is large. With the increase of span, the weight of the structure increases, and the span capacity of the bridge is limited. When the continuous beam bridge is adopted, the tensile stress may be larger in the upper concrete, which will cause cracks in the concrete, thus affecting the durability and service performance of the bridge structure. So in the research of this paper, it is proposed that the light composite beam structure should be adopted on the super large span suspension bridge, the main structural form of which is UHPC) and orthotropic steel bridge panel is combined by shear joint. Because UHPC has the advantages of high strength, good durability, small shrinkage and creep, and good volume stability, combining it with orthotropic steel bridge panel can significantly reduce the weight of the structure and improve the span ability of the bridge. This kind of composite structure not only improves the overall mechanical performance of the bridge, but also increases the local mechanical behavior of orthotropic plates under vehicle wheel loads. Based on the example of super-span suspension bridge across Qiongzhou Strait, the temperature gradient simulation of lightweight composite beam is carried out as follows: based on the theory of solar radiation and heat transfer between structure and external environment. The third kind of boundary condition for temperature field analysis of light composite beam bridge under sunshine is established, and the temperature gradient of light composite beam bridge panel is obtained. At the same time, the influence of asphalt pavement on the temperature gradient of light composite beam is analyzed. Finally, the main parameters affecting the temperature gradient are analyzed. The main cable shape and the internal force of the main cable are calculated by using the analytical method and the finite element analysis respectively. Compared with the two calculation results, it is feasible to use the finite element method to calculate the suspension bridge. Therefore, finite element analysis can be used to calculate the static force of long-span suspension bridge. The static behavior of light composite beam on super-span suspension bridge is calculated by linear second-order method and nonlinear method, respectively. The comparison of two kinds of calculation results shows that it is feasible to use the simpler linear second-order method to calculate the light composite beam and the traditional steel box girder scheme: the original bridge scheme, that is, the steel box girder with asphalt concrete scheme and the light weight combination scheme, is compared with the traditional steel box girder scheme. The beam scheme is compared in terms of mechanical performance and economy. The calculation results show that it is more advantageous to adopt light composite beam in super long span suspension bridge.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.25

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