矮塔斜拉桥施工监控及受力性能若干问题的研究

发布时间：2018-09-04 17:39

【摘要】：矮塔斜拉桥是一种介于普通斜拉桥与传统梁桥之间的新型桥梁。其建造过程工况变化多,应力与线形控制复杂,因此需要施工监控来保证施工安全和质量。本文以某在建宽幅矮塔斜拉桥为研究背景,主要做了以下工作:利用有限元软件Midas Civil建立全桥杆系模型,对施工过程中的各工况进行模拟,从而得到了不同工况下相关控制截面的内力和挠度。在此基础上,研究了施工顺序改变以及施工方案改变后的影响。本文总结了作为监控中的关键问题—应力和线形的控制,对矮塔斜拉桥拉索单根张拉中保证每根钢绞线受力均匀的张拉方法给出了一种简单计算公式,通过实际监测进行了验证。针对宽幅桥梁剪力滞效应突出的特点,采用Midas FEA建立实体模型,模拟施工阶段的各工况,并建立了与之对应的杆系模型,详细分析了剪力滞效应。结果表明:张拉横隔板处横向预应力钢束对于控制截面纵向正应力的影响很小;混凝土浇筑引起的控制截面剪力滞效应亦不明显;张拉纵向预应力对于测点位置容易造成应力集中;斜拉索的张拉容易引起局部应力明显增大,剪力滞效应明显显现;在宽幅箱梁应力监测中,宜采用实体建模的方法获取测点理论值。挂篮设备作为悬臂浇筑的支撑体系,与宽幅箱梁施工密切相关,本文专门对其进行了研究。通过建立有限元模型,对挂篮在不同的工况下的受力和变形做了分析,并进行了抗倾覆安全性验算等。结果表明:施工用挂篮具有安全合理性。进行桥梁动静荷载试验是研究桥梁受力性能的直接途径。本文通过制定该桥的荷载试验方案,并对试验数据进行分析,进一步探究了背景斜拉桥的受力性能,为该桥设计合理性和安全性提供了依据。
[Abstract]:The low-pylon cable-stayed bridge is a new type of bridge between ordinary cable-stayed bridge and traditional girder bridge. Its construction process is changeable, stress and linear control is complex, so construction monitoring is needed to ensure construction safety and quality. Das Civil establishes the whole bridge pole system model and simulates the various working conditions during the construction process, thus obtaining the internal forces and deflections of the relevant control sections under different working conditions. A simple calculation formula is given to ensure the uniformity of each strand in the single cable tension of a low-pylon cable-stayed bridge, which is verified by practical monitoring. Aiming at the prominent shear lag effect of a wide-span bridge, a solid model is established by Midas FEA to simulate the working conditions in the construction stage, and the corresponding poles are established. The results show that the transverse prestressing tendon at the diaphragm has little effect on the longitudinal normal stress of the control section, the shear lag effect of the control section caused by concrete placement is not obvious, the longitudinal prestressing tends to cause stress concentration at the measuring point, and the tension of the cable is easy to lead to stress concentration. In the stress monitoring of wide box girder, the solid modeling method should be adopted to obtain the theoretical value of measuring points. As the supporting system of cantilever casting, the hanging basket equipment is closely related to the construction of wide box girder. The results show that the traveling basket used in construction is safe and reasonable. The dynamic and static load test is a direct way to study the mechanical performance of the bridge. This paper makes a load test plan for the bridge and analyzes the test data to further explore. The mechanical performance of the cable-stayed bridge in the background provides a basis for the design rationality and safety of the bridge.
【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】：U445.4

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