大跨度施工猫道抗风稳定及风振舒适性研究

发布时间：2018-06-06 18:27

本文选题：大跨猫道 + 静风稳定性　；参考：《西南交通大学》2017年硕士论文

【摘要】：随着经济社会的飞速发展及各项技术的不断成熟进步,悬索桥的设计与建造正向超大跨度方向发展。与此同时,悬索桥施工过程中的重要临时结构—施工猫道也越来越轻盈,跨度越来越大。在大跨轻盈结构中,风荷载作用下的静力稳定及动力响应问题是重要的研究对象。由于悬索桥上部结构施工属高空作业,猫道所受风荷载较大,另外猫道作为整个悬索桥上部结构的施工平台,使用周期比较长,风对猫道的影响比较明显。为了保证施工猫道的抗风稳定性和施工安全,为施工人员提供一个舒适的操作平台,对大跨施工猫道进行抗风稳定及施工舒适性评价可以为以后超大跨径悬索桥施工猫道的相关研究提供依据和借鉴。本文利用西南交通大学工业风洞实验室,以某大跨悬索桥施工猫道作为研究对象,测试了其在均匀流条件下的三分力系数;初始位移激励下,猫道竖弯和扭转两自由度耦合振动,结合利用最小二乘复指数方法(简称LSCE法)识别出猫道的颤振导数;通过大型有限元分析软件ANSYS编制相关命令流,利用猫道节段模型静力三分力试验结果,对猫道进行了非线性抗风静力稳定性分析;结合识别出的颤振导数,利用MATLAB软件计算分析猫道在脉动风作用下的抖振响应,得到猫道抖振动力响应的相关特点;参考英国相关标准对施工猫道进行施工舒适性评价。研究结果表明,该悬索桥猫道静风稳定性满足设计要求,且竖向、横向位移较大的位置均出现在中跨猫道,扭转角较大值虽然也出现在中跨猫道,但因横向通道的影响并不是中跨猫道1/2跨位置处,而是在文中标记的HT3和HT4之间的小跨跨中(ZX2);施工阶段常遇风速和设计风速下的猫道抖振响应竖向位移及扭转角RMS值最大处位于中跨1/4处,横向位移RMS值最大处位于中跨1/2处,而竖、横向加速度RMS值最大处在施工常遇风速下位于中跨1/2处,在设计风速下位于中跨1/4处;在可施工风速情况下,参考英国相关标准,猫道竖向与横向昼间振动剂量未超限,夜间振动剂量超限,即猫道昼间施工舒适性可以满足要求,夜间则不能完全满足。故建议夜间风速较大时不进行长时间施工。
[Abstract]:With the rapid development of economy and society and the development of various technologies, the design and construction of suspension bridge is developing in the direction of super span. At the same time, the construction catwalk, which is an important temporary structure in the construction process of suspension bridge, is becoming more and more light and span. In long-span lightweight structures, the static stability and dynamic response under wind load are important research objects. Because the superstructure construction of suspension bridge belongs to aerial work, the catwalk is subjected to large wind load. In addition, as the construction platform of the whole suspension bridge superstructure, the use period of the catwalk is longer, and the influence of wind on cat track is obvious. In order to ensure the wind stability and construction safety of the construction catwalk, it provides a comfortable operating platform for the construction personnel. The evaluation of wind stability and construction comfort of long-span catwalk construction can provide the basis and reference for the related research on the construction of catwalk of long-span suspension bridge in the future. In this paper, using the laboratory of industrial wind tunnel of Southwest Jiaotong University, taking a long span suspension bridge construction catwalk as the research object, the three-point force coefficient under uniform flow condition and initial displacement excitation are tested. Combined with the coupled vibration of vertical bending and torsion of cat track, the flutter derivative of cat track is identified by using the least square complex exponent method (LSCE), and the relevant command flow is compiled by ANSYS, a large-scale finite element analysis software. Based on the static three-point test results of the catwalk segment model, the nonlinear wind-resistant static stability of the catwalk is analyzed, and the chattering response of the catwalk under pulsating wind is calculated and analyzed by using MATLAB software combined with the recognized flutter derivative. The characteristics of buffeting dynamic response of the catwalk are obtained, and the construction comfort of the catwalk is evaluated by referring to the relevant British standards. The results show that the static wind stability of the catwalk of the suspension bridge meets the design requirements, and the positions with large vertical and transverse displacement appear in the mid-span catwalk, and the larger torsion angle also appears in the mid-span catwalk. But because of the transversal passage, it's not a 1 / 2 cross position in the middle of a catwalk. The maximum vertical displacement and torsion angle of catwalk buffeting response under wind speed and design wind speed are located at 1 / 4 of middle span, and the maximum value of lateral displacement RMS is located at 1 / 2 of middle span. The vertical, transverse acceleration RMS value is located at 1 / 2 of the middle span under the normal wind speed, and at 1 / 4 of the middle span under the design wind speed. In the case of the constructible wind speed, and with reference to the relevant British standards, the vertical and transverse diurnal vibration doses of the catwalk are not exceeded. The night vibration dose exceeds the limit, that is, the daytime construction comfort can meet the requirements, but at night it can not be completely satisfied. Therefore, it is suggested that no long-term construction should be carried out when the wind speed is large at night.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445

【参考文献】