单塔地锚式钢桁加劲悬索桥的抗震性能分析

发布时间：2018-12-23 10:18

【摘要】：悬索桥是一种常见的结构形式,它优美的桥型和强大的地域适应性,越来越多被运用在我国的公路铁路交通领域。人们通常将桥梁建在重要的交通枢纽处,地震来的时候如果桥梁被破坏,灾后救援和灾后重建将受到极大影响,因此国内外学者对大跨度悬索桥的抗震进行了大量研究,但对于单塔悬索桥的研究还比较少,而且规范对悬索桥抗震尚未有完善要求,因此对单塔地锚式钢桁加劲悬索桥的进行地震反应分析,获得规律性结论以指导类似的抗震设计是十分有意义的。本文依托福建沙县府前新悬索桥,对单塔悬索桥的抗震性能进行分析研究。沙县府前新悬索桥是一座单塔钢桁架悬索桥,有两个主跨,皆为112米。钢桁架是一种比较新的结构形式。本文运用MIDAS/CIVIL2013有限元软件对福建省沙县府前新悬索桥建立了动力模型,分别对该模型进行动力特性分析、反应谱分析和动态时程分析,综合概述如下：首先,介绍了迄今为止国内外悬索桥的发展历史,并有重点的介绍了桥梁地抗震分析现状,并明确了本文的研究目标和研究内容。其次,详细介绍了沙县府前新悬索桥动力计算模型的建模过程,具体分析了对主缆、主塔、钢桁架以及边界条件的模拟,并记录了成桥后的桥梁线形,分析了主塔、主缆和加劲梁刚度的改变对单塔悬索桥动力性能的影响,可以为单塔地锚钢桁加劲梁悬索桥结构体系的动力设计提供依据。然后,对抗震设防水准和反应谱分析理论做了简要介绍,接着又概括了反应谱理论的地震作用计算方法和组合方法,再根据新沙县府前悬索桥的地质情况,参照相关规范,对新沙县府前悬索桥进行反应谱分析,对结构物输入七种不同方向的地震波,得出了主塔底部的内力和塔顶与主梁跨中的位移。最后,对新沙县府前悬索桥进行地震时程响应分析,分析在不同地震波作用下单塔悬索桥的动力特性及地震响应,并比较了反应谱法和时程法在单塔悬索桥抗震分析上的异同。
[Abstract]:Suspension bridge is a common structural form. It is more and more used in the field of highway and railway transportation because of its beautiful bridge type and strong regional adaptability. People usually build bridges at important transportation hubs. If bridges are damaged when earthquakes come, rescue after disasters and reconstruction after disasters will be greatly affected. Therefore, scholars at home and abroad have done a lot of research on the earthquake resistance of long-span suspension bridges. However, there are few researches on single tower suspension bridge, and the seismic response of single tower ground anchor steel truss suspension bridge is not yet perfect in the code, so the seismic response analysis of single tower ground anchor steel truss suspension bridge is carried out. It is very meaningful to obtain regular conclusions to guide similar seismic design. Based on the new suspension bridge in front of Shaxian County, Fujian Province, the aseismic performance of single tower suspension bridge is analyzed and studied in this paper. The new suspension bridge in front of Shaxian government is a single tower steel truss suspension bridge with two main spans of 112 meters. Steel truss is a relatively new structural form. In this paper, MIDAS/CIVIL2013 finite element software is used to establish the dynamic model of the new suspension bridge in front of Shaxian County, Fujian Province. The dynamic characteristics analysis, response spectrum analysis and dynamic time history analysis of the model are carried out, which are summarized as follows: firstly, This paper introduces the development history of suspension bridges at home and abroad up to now, and emphatically introduces the present situation of seismic analysis of bridges, and clarifies the research objectives and contents of this paper. Secondly, the modeling process of the dynamic calculation model of the new suspension bridge in front of Shaxian prefecture is introduced in detail, and the simulation of the main cable, the main tower, the steel truss and the boundary conditions is analyzed in detail, and the bridge alignment after the bridge is recorded, and the main tower is analyzed. The influence of the stiffness of the main cable and stiffened beam on the dynamic performance of the single tower suspension bridge can provide a basis for the dynamic design of the single tower ground anchor steel truss stiffened beam suspension bridge. Then, the theory of seismic fortification level and response spectrum analysis is briefly introduced, and then the calculation method and combination method of seismic action of response spectrum theory are summarized. According to the geological conditions of the suspension bridge in front of Xinsha County, the relevant codes are referred to. By analyzing the response spectrum of the suspension bridge in front of Xinsha county, the internal force at the bottom of the main tower and the displacement between the top of the tower and the span of the main beam are obtained. Finally, the seismic time-history response analysis of the suspension bridge in Xinsha County is carried out, the dynamic characteristics and seismic response of the single tower suspension bridge under different seismic waves are analyzed, and the similarities and differences between the response spectrum method and the time-process method in the seismic analysis of the single tower suspension bridge are compared.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55;U448.25

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