斜拉桥地震响应时程分析及减震优化

发布时间：2018-09-10 20:08

【摘要】：随着大跨度桥梁的建设增多,斜拉桥在桥梁工程中得到了大范围的使用。斜拉桥逐渐成为交通运输的枢纽,但是其历史较短,对其地震响应以及减震研究不是非常成熟。并且斜拉桥的受力形式与其他形式的桥梁不同,其一旦在地震中遭受破坏不仅会造成非常大的经济损失还会给人民的生命安全造成很大的威胁,因此研究其地震响应及减震方法有着非常重要的意义。本文以某斜拉桥为工程背景,建立有限元模型,对其动力响应以及减震措施进行了系统的研究,主要的工作内容包括以下几个方面:(1)综述了斜拉桥的研究背景以及其发展和现状,阐述了斜拉桥的特点以及震害。(2)阐述了斜拉桥的抗震理论、分析方法、地震动的选择和输入模式以及减隔震理论及其适用范围。(3)结合某斜拉桥工程实例使用有限元软件ANSYS建立了斜拉桥模型,并对建模过程中主梁、主塔、拉索以及粘滞阻尼器和铅芯橡胶支座的模拟方法做了详细的介绍。(4)对斜拉桥模型进行了多种不同组合下地震激励的动力时程分析,将各种不同方向激励组合下的结构响应进行分析对比,可知斜拉桥是一种空间性比较强的结构,任意一个方向的地震波激励都会结构的三个方向的运动给带来影响。因此在进行斜拉桥抗震分析时,要考虑三个不同方向地震激励的组合。(5)对斜拉桥模型进行三条不同地震波激励下的响应分析,确定使斜拉桥结构产生最不利响应的地震波为抗震分析时的地震激励。(6)对斜拉桥三种不同的减震措施即粘滞阻尼器、铅芯橡胶支座以及粘滞阻尼器+铅芯橡胶支座进行地震响应分析。并且分别对铅芯橡胶支座的铅芯直径和粘滞阻尼器的阻尼系数进行了优化分析。最后对比分析三种减震措施下结构的地震响应以确定最佳的减震方案。(7)最后对于本文研究的内容做了总结,并对其中的不足和进一步的研究方向做了阐述。
[Abstract]:With the increasing construction of long-span bridges, cable-stayed bridges are widely used in bridge engineering. Cable-stayed bridge is gradually becoming the hub of transportation, but its history is relatively short, so the research on its seismic response and damping is not very mature. Moreover, the stress forms of cable-stayed bridges are different from those of other types of bridges. Once damaged in an earthquake, the cable-stayed bridges will not only cause great economic losses, but also pose a great threat to the lives and safety of the people. Therefore, it is of great significance to study its seismic response and damping method. In this paper, the finite element model of a cable-stayed bridge is established, and its dynamic response and seismic absorption measures are systematically studied. The main work includes the following aspects: (1) the research background, development and present situation of cable-stayed bridge are summarized, and the characteristics and earthquake damage of cable-stayed bridge are expounded. (2) the seismic theory and analysis method of cable-stayed bridge are expounded. The selection and input mode of ground motion as well as the theory of seismic isolation and its application scope. (3) the cable stayed bridge model is established with the finite element software ANSYS, and the main beam and main tower in the process of modeling are established with the example of a cable-stayed bridge project. The simulation methods of cable, viscous damper and lead rubber bearing are introduced in detail. (4) dynamic time-history analysis of seismic excitation of cable-stayed bridge model under various combinations is carried out. By analyzing and comparing the structural responses of different direction excitation combinations, it can be seen that cable-stayed bridge is a kind of structure with strong spatial property, and the movement of three directions of the structure will be affected by seismic wave excitation in any direction. Therefore, in the seismic analysis of cable-stayed bridges, the combination of three different directions of earthquake excitation should be considered. (5) the response analysis of the cable-stayed bridge model under three different seismic waves is carried out. The seismic wave that causes the most unfavorable response of the cable-stayed bridge structure is determined to be the seismic excitation in seismic analysis. (6) for the cable-stayed bridge, three kinds of different damping measures, that is, viscous dampers, are considered. The seismic response of lead rubber bearings and viscous dampers are analyzed. The lead diameter of lead rubber bearing and damping coefficient of viscous damper are optimized. Finally, the seismic responses of the structures under three kinds of seismic absorption measures are compared and analyzed to determine the best seismic absorption scheme. (7) at last, the contents of this paper are summarized, and the shortcomings and further research directions are described.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55;U448.27

【参考文献】