城市大跨度钢拱桥地震反应分析

发布时间：2018-03-19 18:21

本文选题：钢拱桥　切入点：抗震分析　出处：《兰州交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：进入二十一世纪以来,随着我国拱桥施工技术的日益成熟及钢铁冶炼技术的迅猛发展,我国修建的钢拱桥在数量和跨径两方面都出现了飞跃式的发展。钢拱桥不仅具有很高的承载力,同时由于具有较高的强度比,因此能够设计成大跨度桥梁。钢拱桥还有结构形式优美的特点,因此在桥梁建设中备受青睐,目前在铁路、公路和市政桥梁中都得到广泛的应用。本论文依托兰州市一座下承式钢拱桥为工程背景,懫用MIDAS/CIVIL有限元软件建立全桥空间模型,研究其地震反应。主要研究内容有以下几个方面:(1)首先介绍了国内外钢拱桥的发展现状、抗震研究现状及震害特点。其次根据目前桥梁抗震设计的发展概况,介绍了桥梁抗震分析的基本方法,为城市大跨度钢拱桥的地震反应分析提供了一定的理论基础。(2)根据结构动力学理论,利用空间有限元分析软件MIDAS/CIVIL建立钢拱桥的全桥空间有限元计算模型,对该桥自振特性进行研究。分析过程中考虑了桩土相互作用以及主拱外倾角度的变化,研究了拱肋倾角对该桥动力特性的影响。(3)在动力特性分析的基础上,依据该桥安评报告确定反应谱曲线,并采用反应谱分析方法进行抗震计算。在E1地震动作用下,考虑主拱倾斜角度变化及大桥在纵向、横向、纵+竖、横+竖四种不同输入方式下的地震反应分析对比,探讨不同地震动输入方式及拱肋倾角对大跨度钢拱桥反应谱分析结果的影响。(4)在罕遇地震下,采用非线性动力时程分析法,对该桥在一致激励下分别按纵向和横向两种输入方式输入三条强震记录地震波,进行不同输入方式下的地震反应分析对比。结合摩擦摆支座(FPB)的相关力学模型及计算参数,对使用了摩擦摆支座的模型进行时程分析,探讨了FPB支座的减隔震效果。通过对以上问题的分析研究,对该钢拱桥的动力特性、该桥的抗震最不利地震波输入组合以及摩擦摆支座的隔震性能有了更为深刻的认识,并对类似桥型的抗震薄弱环节提出合理化的设计建议。
[Abstract]:Since 21th century, with the maturation of arch bridge construction technology and the rapid development of iron and steel smelting technology in China, The steel arch bridges built in China have developed rapidly in both quantity and span. The steel arch bridges not only have high bearing capacity, but also have high strength ratio. So it can be designed to be a long span bridge. Steel arch bridge also has the characteristics of beautiful structure, so it is very popular in bridge construction. At present, it is on the railway. Both highway and municipal bridges are widely used. Based on the engineering background of a through steel arch bridge in Lanzhou City, this paper uses MIDAS/CIVIL finite element software to establish the spatial model of the whole bridge. The main research contents are as follows: firstly, the development status, seismic research status and earthquake damage characteristics of steel arch bridges at home and abroad are introduced. Secondly, according to the development situation of aseismic design of bridges at present, This paper introduces the basic method of seismic analysis of bridges, which provides a theoretical basis for seismic response analysis of large span steel arch bridges in cities. The spatial finite element model of the steel arch bridge is established by using the spatial finite element analysis software MIDAS/CIVIL, and the natural vibration characteristics of the bridge are studied. The pile-soil interaction and the variation of the angle of inclination outside the main arch are taken into account in the analysis. The influence of arch rib inclination angle on the dynamic characteristics of the bridge is studied. Based on the analysis of the dynamic characteristics, the response spectrum curve is determined according to the bridge safety evaluation report, and the seismic calculation is carried out by using the response spectrum analysis method. Considering the variation of the inclination angle of the main arch and the analysis and comparison of the seismic response of the bridge under four different input modes: longitudinal, transverse, vertical and vertical, The influence of different input modes of ground motion and the inclination of arch rib on the results of response spectrum analysis of long-span steel arch bridges is discussed. The nonlinear dynamic time-history analysis method is used in rare earthquakes. Under uniform excitation, three strong earthquake recorded seismic waves were inputted into the bridge under the same excitation, and the seismic response of the bridge was analyzed and compared under different input modes. In combination with the relevant mechanical model and calculation parameters of the friction pendulum bearing FPBs, the seismic response of the bridge was analyzed and compared. In this paper, the time history analysis of the model of friction pendulum bearing is carried out, and the seismic isolation effect of FPB bearing is discussed. The dynamic characteristics of the steel arch bridge are studied through the analysis of the above problems. The most unfavorable seismic wave input combination of the bridge and the seismic isolation performance of the friction pendulum bearing have a deeper understanding, and some reasonable design suggestions for the seismic weak link similar to the bridge type are put forward.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55

【相似文献】