大跨度公铁两用悬索桥结构参数与力学特性研究

发布时间：2019-05-18 23:37

【摘要】：目前,千米级公铁两用悬索桥建成的不多,还未出版明确的设计规范和参考依据,现有的设计依旧处于探索阶段。对于大跨度公铁两用悬索桥而言,刚度是一个关键的控制性指标,影响刚度的结构参数很多,研究其对于悬索桥刚度的影响十分重要。此外,大跨度桥梁地震反应十分复杂,需要考虑行波效应、多点激励、几何非线性等因素的影响,目前没有统一的抗震设计规范,抗震设计比较复杂。因此,研究大跨度公铁两用悬索桥在地震作用下的响应对于抗震的概念设计具有极大的参考价值。本文主要研究了大跨度公铁两用悬索桥结构参数对桥梁刚度敏感性以及扭弯比的影响;研究了结构参数下在反应谱荷载作用下的主梁的位移响应,并总结了刚度变化规律;对比了不同地震波作用下,行波效应对桥梁地震响应的影响;此外设置了抗震结构,总结了其对地震响应的影响规律;最后研究了施工阶段的非线性及施工吊装阶段动力特性的变化,主要研究内容包括:(1)总结了悬索桥的发展历史以及公铁两用悬索桥的主要研究现状,研究并整理了本文所需要的静动力计算理论,为后文的工作打下基础。(2)研究跨径超1000m的公铁两用悬索桥并进行静力计算,研究了成桥状态下的受力特性,并且在考虑列车活载工况以及横向风荷载工况下的受力变化规律,并探讨垂跨比、主缆截面、加劲梁恒载对于悬索桥竖向刚度和横向刚度的影响,以及总结了主缆内力及塔顶位移随结构参数的变化规律,为悬索桥设计提供参考依据。(3)研究跨径超1000m的公铁两用悬索桥的动力特性,并探讨总结了垂跨比、主缆截面、加劲梁重量对于扭弯比的影响;同时研究并且分析了在反应谱荷载工况下,主梁位移响应随垂跨比、梁高、梁宽的变化规律;研究了地震作用工况下悬索桥的受力特性,以及多点激励下体系的地震响应,并与一致激励进行对比;探讨了中央扣和减震器对于结构地震响应的影响。(4)由于悬索桥施工周期较长,悬索桥遭受地震及大风的袭击概率较高,本文研究了跨径超1000m的公铁两用悬索桥施工阶段结构行为,同时研究结构在施工阶段的结构动力特性,为抗风和抗震设计提供参考。
[Abstract]:At present, few suspension bridges have been built, and the clear design specifications and reference have not yet been published, and the existing design is still in the exploratory stage. For long-span public-railway suspension bridge, stiffness is a key control index, and there are many structural parameters that affect stiffness, so it is very important to study its influence on the stiffness of suspension bridge. In addition, the seismic response of long-span bridges is very complex, so it is necessary to consider the effects of traveling wave effect, multi-point excitation, geometric nonlinear and other factors. At present, there is no unified seismic design code, and the seismic design is more complex. Therefore, it is of great reference value to study the response of long-span public railway suspension bridge under earthquake action for the conceptual design of earthquake resistance. In this paper, the influence of structural parameters on stiffness sensitivity and torsional bending ratio of long-span public iron suspension bridge is studied, and the displacement response of main beam under response spectrum load is studied, and the variation law of stiffness is summarized. The influence of traveling wave effect on seismic response of bridge under different seismic waves is compared, and the seismic structure is set up, and the influence law of traveling wave effect on seismic response is summarized. Finally, the nonlinear of the construction stage and the change of the dynamic characteristics of the construction hoisting stage are studied. The main research contents are as follows: (1) the development history of the suspension bridge and the main research status of the public railway suspension bridge are summarized. The static and dynamic calculation theory needed in this paper is studied and sorted out, which lays the foundation for the later work. (2) the suspension bridge with span of more than 1000m is studied and the static calculation is carried out, and the mechanical characteristics of the bridge under the condition of completion are studied. The effects of vertical span ratio, main cable section and stiffened beam dead load on the vertical stiffness and transverse stiffness of suspension bridge are discussed under the consideration of the variation law of train live load and transverse wind load, and the influence of vertical span ratio, main cable section and stiffened beam dead load on vertical stiffness and transverse stiffness of suspension bridge is discussed. The variation of the internal force of the main cable and the displacement of the tower top with the structural parameters is summarized, which provides a reference for the design of the suspension bridge. (3) the dynamic characteristics of the suspension bridge with a span of more than 1000 m are studied, and the vertical span ratio and the section of the main cable are discussed and summarized. The influence of the weight of stiffened beam on torsional bending ratio; At the same time, the variation of displacement response of main beam with vertical span ratio, beam height and beam width under response spectrum load is studied and analyzed. The stress characteristics of suspension bridge under seismic action and the seismic response of the system under multi-point excitation are studied and compared with the uniform excitation. The influence of central buckle and shock absorber on the seismic response of the structure is discussed. (4) because of the long construction period of the suspension bridge, the probability of earthquake and strong wind attack on the suspension bridge is higher. In this paper, the structural behavior of the public railway suspension bridge with a span of more than 1000 m is studied, and the structural dynamic characteristics of the structure in the construction stage are studied, which provides a reference for wind resistance and seismic design.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.25

【参考文献】