大跨度斜拉桥地震响应分析

发布时间：2018-04-02 19:52

本文选题：大跨度斜拉桥　切入点：动力特性　出处：《北京交通大学》2014年硕士论文

【摘要】：摘要：随着我国经济的快速发展,道路交通事业作为基础设施中最关键的部分正蓬勃发展,而大跨度桥梁通常是道路交通中的枢纽工程。大跨度斜拉桥由于构造新颖、跨越能力大,成为桥梁领域的主角之一。大跨度斜拉桥具有独特的静、动力性能,对大跨度斜拉桥进行地震响应进行分析研究,能够有效保证其在强震作用下的安全。本文首先介绍国内外大跨度桥梁发展现状及常用的抗震分析方法,再以大跨度斜拉桥苏通长江公路大桥为工程背景,用有限单元法,建立该桥的空间动力模型,对其自身动力特性及在地震作用下的响应进行深入分析,主要研究如下： (1)首先介绍了大跨度斜拉桥的结构特点及国内外斜拉桥的发展状况,并阐述对其抗震反应分析的必要性；并对大跨斜拉桥地震分析中现存的一些问题进行探讨。 (2)归纳总结了现有斜拉桥地震响应分析方法,详细介绍了反应谱法、时程分析法的基本原理,以及相应的计算公式。 (3)以有限元软件MIDAS/CIVIL为计算平台,建立苏通长江公路大桥的空间动力模型,分别对是否设置减震耗能装置两种情况,进行动力特性分析,并对计算结果进行比较分析,阐明减震耗能装置对结构动力特性的影响及重要性。 (4)通过计算桥梁的有效振型参与质量,确定参与振型分解反应谱法模态阶数的数量,同时根据大桥所处的场地条件确定采用的反应谱,对桥梁进行五种工况下的地震响应进行分析。 (5)结合大桥所处的场地条件,选取合适的地震波。在一致地震激励下进行大桥的地震响应时程分析,重点分析了竖向地震激励对地震响应的影响。 (6)探讨非一致地震激励下的行波效应对桥梁结构地震响应的影响,得到关键截面在不同波速激励下结构的地震响应,并与一致地震激励下大桥的地震响应结果比较,分析得到相应结论,阐述行波效应的重要性。
[Abstract]:Absrtact: with the rapid development of our country's economy, the road traffic industry as the most important part of the infrastructure is booming, and the long-span bridge is usually the key project in the road traffic.Long-span cable-stayed bridge has become one of the leading roles in bridge field because of its novel structure and large span capacity.The long-span cable-stayed bridge has unique static and dynamic performance. The seismic response of long-span cable-stayed bridge is analyzed and studied, which can effectively ensure its safety under strong earthquake.This paper first introduces the development situation of long-span bridges at home and abroad and the commonly used seismic analysis methods, and then, taking the Sutong Yangtze River Highway Bridge, a long-span cable-stayed bridge, as the engineering background, establishes the spatial dynamic model of the bridge by using the finite element method.The dynamic characteristics and the response under earthquake are analyzed. The main results are as follows:Firstly, the structural characteristics of long-span cable-stayed bridges and the development of cable-stayed bridges at home and abroad are introduced, and the necessity of seismic response analysis of long-span cable-stayed bridges is expounded, and some existing problems in seismic analysis of long-span cable-stayed bridges are discussed.(2) the existing seismic response analysis methods of cable-stayed bridges are summarized, and the basic principles of response spectrum method, time-history analysis method and corresponding calculation formulas are introduced in detail.Based on the finite element software MIDAS/CIVIL, the spatial dynamic model of Sutong Yangtze River Highway Bridge is established. The dynamic characteristics of the two cases are analyzed, and the calculation results are compared and analyzed.The influence and importance of the energy dissipation device on the dynamic characteristics of the structure are expounded.(4) by calculating the participating quality of the effective modes of the bridge, determining the number of the modal order of the mode decomposition response spectrum method, at the same time determining the response spectrum according to the site condition of the bridge.The seismic response of the bridge under five working conditions is analyzed.Combined with the site conditions of the bridge, the appropriate seismic waves are selected.The seismic response time history analysis of the bridge under uniform earthquake excitation is carried out, and the influence of vertical earthquake excitation on the seismic response is emphatically analyzed.The influence of traveling wave effect on the seismic response of bridge structure under non-uniform earthquake excitation is discussed. The seismic response of the key section under different wave velocity excitation is obtained and compared with the seismic response result of the bridge under uniform earthquake excitation.The conclusion is obtained and the importance of traveling wave effect is expounded.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.27;U442.55

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