忠建河大桥（钢桁梁斜拉桥）施工期风致抖振响应控制措施研究

发布时间：2018-06-10 14:58

本文选题：斜拉桥 + 钢桁主梁　；参考：《广西大学》2017年硕士论文

【摘要】：随着桥梁跨径的不断加大和新材料、新结构的大量应用,以及制造工艺的日渐优化,桥梁结构体系刚度和阻尼呈现出明显的下降趋势,桥梁结构对大气风作用的敏感性也越来越突出。剧烈的桥梁风致振动将不可避免的影响到桥梁结构安全和施工的顺利进行,这是亟待解决的问题。因此,对桥梁施工期风致抖振响应的控制措施进行专门的研究具有重要的工程实践意义。本文依托湖北恩施至来凤高速公路上的忠建河大桥,针对钢桁梁斜拉桥的结构特点,主要对大桥钢桁主梁施工期风致抖振响应控制措施进行了研究。论文首先阐述了国内外大跨径斜拉桥的发展历史,介绍了桥梁风致抖振的理论基础和研究现状,以及钢桁梁斜拉桥施工风振控制的研究进展。随后介绍了桥梁风致振动控制的常见措施,简要介绍了背景工程忠建河钢桁梁斜拉桥的相关设计参数,明确了以设置抗风索的机械措施作为该桥施工期风致抖振控制研究的重点。在此基础上,论文参考规范要求,确定了该桥施工阶段的主梁设计基本风速,利用大型通用流体分析软件FLUENT,采用数值模拟的方法获取了忠建河特大桥施工阶段钢桁主梁的静力三分力系数;同时,在通用结构软件ANSYS中建立了忠建河特大桥的结构有限元模型,使用MATLAB模拟程序生成了满足条件的脉动风场和桥梁抖振力荷载时程样本,并导入到ANSYS模型中进行结构动力响应分析。论文对钢桁梁斜拉桥施工阶段钢桁主梁在最大单悬臂和最大双悬臂两种典型状态下的风致静风响应和风致抖振响应进行了计算和分析,重点研究了抗风索对钢桁梁斜拉桥钢桁主梁典型施工状态的静风变形和振动抑制效果。得到了如下结论:(1)不设置抗风索时,钢桁主梁最大单悬臂状态的最大静风位移发生在悬臂端;最大双悬臂状态的最大静风位移发生在河侧悬臂端。(2)不设置抗风索时,最大双悬臂状态具有更大的悬臂端主梁抖振位移,更大的抖振位移相应导致了更大的主梁抖振内力响应。(3)设置抗风索后,能够在一定程度上使钢桁主梁的静风位移得到抑制。且随抗风索截面积的不同,抑制效果也不同;抗风索截面积越大,抑制效果越好。抗风索截面积相同条件下,拉结于地面的方案A比拉结于塔底承台的方案B能更好的抑制钢桁主梁在静风作用下的变形。(4)设置抗风索后,能够有效抑制施工阶段钢桁主梁的风致抖振响应;且抗风索截面积越大,抗风索对主梁的抖振位移和抖振内力抑制效果越显著。抗风索截面积相同条件下,对主梁的抖振位移和抖振内力抑制效果方面,拉结于地面的方案A整体上明显优于拉结于塔底承台的方案B。
[Abstract]:With the increasing span of bridges, new materials, large applications of new structures, and the increasing optimization of manufacturing technology, the stiffness and damping of bridge structure system show an obvious downward trend. The sensitivity of bridge structure to atmospheric wind is more and more prominent. The violent wind-induced vibration of bridges will inevitably affect the safety of bridge structure and the smooth progress of construction, which is an urgent problem to be solved. Therefore, it is of great practical significance to study the control measures of wind-induced buffeting response during bridge construction. Based on the Zhongjian River Bridge on Enshi to Laifeng Expressway in Hubei Province and in view of the structural characteristics of the steel truss girder cable-stayed bridge, the wind-induced buffeting response control measures of the steel truss main girder during the construction period of the bridge are studied in this paper. In this paper, the development history of long span cable-stayed bridge at home and abroad is introduced, the theoretical basis and research status of wind-induced buffeting are introduced, and the research progress of wind-induced vibration control of steel truss cable-stayed bridge is introduced. Then the common measures of wind-induced vibration control are introduced, and the design parameters of Zhongjian River Steel Truss Cable-Stayed Bridge are briefly introduced. The emphasis of the study on wind-induced buffeting control of the bridge during construction is the mechanical measures with wind resistant cables. On this basis, the basic wind speed of the main girder design in the construction stage of the bridge is determined by referring to the requirements of the code. By using fluent, a large scale general fluid analysis software, the static three-point force coefficients of steel truss main girder in construction phase of Zhongjian River Bridge are obtained by numerical simulation. The finite element model of Zhongjian River Bridge is established in the general structure software ANSYS. The pulsating wind field and buffeting load time history samples are generated by MATLAB simulation program. It is introduced into ANSYS model to analyze the dynamic response of the structure. In this paper, the wind-induced static wind response and wind-induced buffeting response of steel truss main girder in two typical states of maximum single cantilever and maximum double cantilever are calculated and analyzed in the construction stage of steel truss cable-stayed bridge. The static wind deformation and vibration suppression effect of steel truss girder main girder in typical construction state of steel truss cable-stayed bridge are studied. It is concluded that the maximum static wind displacement of the steel truss main beam in the single cantilever state occurs at the cantilever end, while the maximum static wind displacement in the maximum double cantilever state occurs at the river side cantilever end. The maximum double cantilever state has larger buffeting displacement of the cantilever end main beam, and the larger buffeting displacement leads to larger buffeting internal force response. 3) after the wind resistant cable is installed, the static wind displacement of the steel truss main beam can be restrained to a certain extent. The inhibition effect is different with the cross section area of the wind rope, and the larger the cross section area of the wind rope is, the better the inhibition effect is. Under the same cross-sectional area of the wind cable, the scheme A and B, which are attached to the ground, can better restrain the deformation of the steel truss girder under the static wind. 4) after the installation of the wind resistant cable, It can effectively restrain the wind-induced buffeting response of steel truss girder in construction stage, and the larger the cross-sectional area of the wind cable, the more significant the effect of the anti-wind cable on the buffeting displacement and the buffeting internal force of the main girder. In the case of the same cross-sectional area of the wind cable, the effect of buffeting displacement and buffeting internal force on the main beam is obviously superior to that of the scheme B in the case of pulling on the ground.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.27

【参考文献】