【作者】 龙飞；

【导师】 许福友；

【作者基本信息】 大连理工大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 自锚式悬索桥以其在景观上的突出优势和其对软基较强的适应能力显示出其强大的生命力。国内研究虽起步较晚,但自1999年开始修建以来的十年间,该桥型在我国得到了迅速发展,跨度也逐渐增大。同时,由于主缆锚固于加劲梁端所带来的巨大轴力使得加劲梁刚度相对较低,导致其抗风性能随之相对较差,鉴于此因,本文以主跨为406m的郑州桃花峪黄河大桥为工程背景,开展大跨度自锚式悬索桥的抗风性能分析与试验研究,具体研究工作包括以下几个方面：(1)对比分析了具有相同结构参数的自锚式和地锚式悬索桥在动力性能方面的差异,研究了边界约束条件、恒载集度、加劲梁刚度、主塔刚度、主缆以及吊索抗拉刚度等结构参数变化对自锚式和地锚式悬索桥动力特性的影响规律。(2)对主梁节段模型开展测力、测振、测压试验。研究了三分力系数平均值、标准差、斜度和峰态随风速、攻角的变化特点,给出一些指导性建议。(3)对比研究了扁平箱梁断面的软颤振和涡激共振的振动响应,研究了不同状态、攻角、风速条件下软颤振振幅、阻尼比、扭转中心偏移情况,分析了原因。(4)对比研究了模型在静止状态下和软颤振过程中表面压力分布情况,通过分析模型振动对表面压力系数平均值和标准差的影响规律,以及各测点扭矩相关性、脉动风压功率谱的变化情况研究扁平箱梁断面振动机理。更多还原

【Abstract】 With its aesthetics advantage and suitability to soft foundations, the self-anchored suspension bridge becomes an increasingly popular choice in bridge design industry. Although the relevant study on self-anchored suspension bridges started late at home, the ten years since 1999 have witnessed a rapid development in its construction nationwide with spans increasing. Its wind-resistant performance, however, declines due to the relatively low girder stiffness as the anchorage of main cables at the ends of the stiffening girder exerts quite large axial force to the girder. Therefore based on Zhengzhou Taohuayu Yellow River Bridge with a main span of 406m, wind-resistant performance analysis and experimental investigation on long-span self-anchored suspension bridges were carried out in this paper. Specifically the study consists of the following aspects:(1) A comparative analysis was undertaken between the dynamic performance of the self-anchored suspension bridge and that of the earth-anchored one with the same structural parameters. And the effect of variation of structural parameters including boundary conditions, dead load distribution, girder stiffness, stiffness of the main towers, tensile stiffness of main cables and slings on the dynamic characteristics of both self-anchored and earth-anchored suspension bridges was studied.(2) Force, vibration and pressure measurement tests were performed on the section model of main girder. Characteristics of variation of the mean value, standard deviation, skewness and kurtosis of three-component coefficients with wind speed and the angle of attack were studied, and some suggestions were also presented.(3) Soft flutter and vortex induced vibration of a flat box girder section were compared. Studies on the soft flutter amplitude, damping ratio, deviation of torsion center under conditions of various states, attack angles and wind speeds were carried out, and the corresponding reasons were analyzed.(4) Comparison of surface pressure distribution of the model in static state and soft flutter was performed, and the vibration mechanism of flat box girder section was studied through the analysis of the influence of model vibration on the mean value and standard deviation of surface pressure coefficient, torsion correlation of various measuring points, and variation of fluctuating wind pressure power spectrum.更多还原