小跨径窄桥面悬索桥结构动力响应研究

发布时间：2018-05-28 13:49

本文选题：简易吊桥 + 动力特性　；参考：《重庆交通大学》2015年硕士论文

【摘要】：小跨径窄桥面悬索桥受力明确跨越能力大并且结构简单、建造成本低、施工便利,与我国西南地区的自然社会条件相适应,适于在该地区建造,为改善当地的交通情况发挥着积极的作用。多数情况下,该类型桥被当作临时结构,设计时采用传统的理论公式法计算,偏重考虑静力荷载作用;而我国地震活动活跃,人们越来越关注地震作用对该类型桥梁的影响。本文结合西南地区一座实际的小跨径窄桥面悬索桥,在静力分析的基础上进行结构动力分析,采用振型分解反应谱法与动力时程法计算结构的地震反应。主要的研究工作如下:①采用理论公式法和有限元法对一座实际的该类型桥进行静力计算,分析其在线型、缆索内力和挠度方面的差异。对比结果表明传统理论公式法偏安全且计算简便高效。②采用模态分析法分析其动力特性,获得结构自振频率和自振模态,为分析加劲梁抗风索对其动力特性的影响,采用有无抗风索的两种模型进行对比计算,分析各主要振型特性和频率的变化情况。研究抗风缆索提高结构的自振频率和提高结构刚度的问题。③采用振型分解反应谱法与动力时程法两种方法计算,结合桥址情况,分别计算常遇地震和偶遇地震作用下的结构响应,并对抗风缆索对地震荷载的影响作出分析,计算不同初始张拉力抗风索对结构地震作用的影响。本文的研究成果可为类似桥梁修建提供有意义的参考。
[Abstract]:The small span narrow deck suspension bridge is suitable for construction in the southwest of China, because it has the advantages of large span capacity, simple structure, low construction cost and convenient construction, which is suitable for the construction of the suspension bridge in the southwest of our country, which is suitable for the construction of the suspension bridge in the southwest of China. Play a positive role in improving local traffic conditions. In most cases, this type of bridge is regarded as a temporary structure, and the traditional theoretical formula method is used to calculate the bridge design, with emphasis on static load, but in our country seismic activity is active, people pay more and more attention to the influence of seismic action on this type of bridge. Based on the static analysis of a practical small span narrow deck suspension bridge in southwest China, the structural dynamic analysis is carried out in this paper. The seismic response of the structure is calculated by using the mode decomposition response spectrum method and the dynamic time-log method. The main research work is as follows: 1. The theoretical formula method and the finite element method are used to calculate the static force of a practical bridge of this type, and the differences of its on-line type, cable internal force and deflection are analyzed. The comparison results show that the traditional theoretical formula method is relatively safe and simple and efficient in calculation. 2. The modal analysis method is used to analyze the dynamic characteristics of the structure. The natural vibration frequency and the natural vibration mode of the structure are obtained. In order to analyze the influence of the wind resistant cable of stiffened beam on its dynamic characteristics, Two kinds of models with or without wind cables are used to compare and calculate, and the variation of the main modes and frequencies is analyzed. In this paper, the problem of increasing the natural vibration frequency and improving the stiffness of the structure with wind resistant cable is studied. 3. 3. The vibration mode decomposition response spectrum method and the dynamic time history method are used to calculate the problem. The structural responses under frequent and accidental earthquakes are calculated, and the effects of wind cables on seismic loads are analyzed, and the effects of different initial tensile forces on the seismic response of structures are calculated. The research results of this paper can provide a meaningful reference for similar bridge construction.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3;U448.25

【共引文献】