中央扣对大跨度悬索桥抗震性能的影响研究

发布时间：2019-03-21 08:47

【摘要】：悬索桥主要由桥塔、主梁、主缆、吊杆以及附属结构部分组成;从结构受力角度上讲,主梁的自重和活载通过主缆和加劲梁之间的吊杆传递到主缆,主缆通过拉力传递到桥塔和锚碇上,因此悬索桥受力非常明确。而在主跨跨中位置设置中央扣将主梁与主缆扣联是大跨度悬索桥提高其结构刚度的有效措施之一。有关悬索桥动力及抗震性能的研究成果很多,但针对设置中央扣悬索桥的动力性能及抗震性能方面的研究工作相对较少。本文以实际的悬索桥为依托工程,研究不同形式的中央扣对大跨度悬索桥抗震性能的影响规律。主要研究内容如下:首先,论述悬索桥上部结构体系的振动理论,推导其结构振动平衡方程,及其整体振动分解为竖直、水平和扭转三种振动的平衡方程及振动性状;介绍几种常用的桥梁抗震分析方法,并详细阐述时程分析方法的理论基础和数值求解方法。然后,基于有限元分析软件建立无、柔性和刚性中央扣的悬索桥模型,进行模态分析,通过比对不同形式的中央扣悬索桥模型的振动特征,总结中央扣对大跨度悬索桥动力性能的影响规律,为进一步的地震时程分析做基础。最后,根据桥梁所在地区的场地条件及结构自身的振动特性,选择合适的地震波。通过调整地震波的峰值加速度来实现结构在频遇地震激励下的弹性时程分析和在强震激励下的弹塑性时程分析。分析比较各模型在相应地震激励下的内力和位移响应,总结出频遇地震作用下及强震作用下中央扣对大跨度悬索桥抗震性能的影响规律。
[Abstract]:Suspension bridge is mainly composed of bridge tower, main beam, main cable, hanger and subsidiary structure. From the structural stress point of view, the dead weight and live load of the main beam are transferred to the main cable through the hanger between the main cable and the stiffened beam, and the main cable is transferred to the bridge tower and Anchorage through the tensile force, so the stress of the suspension bridge is very clear. It is one of the effective measures to improve the structural stiffness of long-span suspension bridge by fastening the main beam with the main cable at the middle position of the main span. There are many research achievements on dynamic and seismic performance of suspension bridge, but the research work on the dynamic performance and seismic performance of central suspension bridge is relatively few. In this paper, based on the actual suspension bridge, the influence of different forms of central buckle on the seismic behavior of long-span suspension bridge is studied. The main research contents are as follows: firstly, the vibration theory of suspension bridge superstructure system is discussed, and the vibration equilibrium equation of suspension bridge superstructure system is deduced, and its whole vibration is decomposed into three kinds of vibration equilibrium equation and vibration behavior of vertical, horizontal and torsional vibration. In this paper, several commonly used seismic analysis methods of bridges are introduced, and the theoretical basis and numerical solution of the time history analysis method are described in detail. Then, based on the finite element analysis software, the suspension bridge model with no, flexible and rigid central buckle is established, and the modal analysis is carried out. By comparing the vibration characteristics of the central suspension bridge model in different forms, the vibration characteristics of the suspension bridge model are compared. The influence of central buckle on the dynamic performance of long span suspension bridge is summarized, which is the basis for further seismic time history analysis. Finally, according to the site conditions of the bridge and the vibration characteristics of the structure itself, a suitable seismic wave is selected. The elastic time history analysis of structures under frequent earthquake excitation and elastoplastic time history analysis under strong earthquake excitation are realized by adjusting the peak acceleration of seismic waves. The internal forces and displacement responses of each model under corresponding earthquake excitation are analyzed and compared, and the effects of central buckle on the seismic performance of long-span suspension bridges under frequent and strong earthquakes are summarized.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55;U448.25

【引证文献】