大跨度混合梁斜拉桥抗震分析研究

发布时间：2018-01-14 00:07

本文关键词：大跨度混合梁斜拉桥抗震分析研究　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：大跨度桥梁一旦遭到地震的严重破坏甚至倒塌,不仅造成交通线本身巨大的损失,导致震区交通的瘫痪,加大救灾工作难度,而且加重次生灾害导致生命财产以及间接经济的损失。大跨度混合梁斜拉桥一般主塔高、跨度大,结构受力复杂,因而其抗震分析研究十分重要。本文以拟建的结构非对称红水河混合梁斜拉桥为工程背景,借助有限元分析软件,建立该桥空间有限元模型,对其动力特性、抗震性能进行计算分析,探讨行波效应和余震对结构受力性能的影响。主要工作和研究成果如下： (1)对桩-土相互作用模拟方法进行了探讨,建立了红水河混合梁斜拉桥的动力有限元模型,对其动力特性进行了计算分析。结果表明该桥模态分布较密,前十五阶自振频率低于1Hz。 (2)采用反应谱法和动力时程分析法,分别计算分析了该结构在E1和E2地震下纵向+竖向和横向+竖向2种组合下的内力、位移和应力响应,并对比分析了两种方法计算地震响应的结果。两种方法计算结果均表明,该桥在E1地震下,构件处于弹性状态；在E2地震下桥墩局部区域出现裂缝,满足小震不坏、大震不倒的基本要求。 (3)在动力时程分析法基础上,考虑行波效应对红水河混合梁斜拉桥地震响应的影响,对比分析了4种波速和一致激励下结构的纵向位移和内力的变化情况。 (4)采用刚度折减法来模拟主震过后各桥墩的损伤,计算结构在余震作用下的响应,分析和对比了结构在E1地震和E2地震的位移和应力的变化情况。结果表明：余震能对桥梁造成接近主震的破坏。
[Abstract]:Long span bridge severely damaged by the earthquake once even collapse, not only caused the traffic line itself huge losses, resulting in the earthquake zone traffic paralysis, increase the difficulty of the relief work, but also aggravate the secondary disasters lead to life and property and the indirect economic loss. Generally the main tower cable-stayed bridge, long span hybrid structure of large span, complex force so it is very important to research the seismic analysis.
In this paper, the structure of cable-stayed bridge as the engineering background of symmetrical Red River is mixed by the finite element analysis software, establish the finite element model of the bridge, the dynamic characteristics, seismic performance calculation and analysis, to explore the influence of traveling wave effect and aftershocks on mechanical properties. The main work and research results are as follows:
(1) the simulation method of pile-soil interaction is discussed, and the dynamic finite element model of the hybrid girder cable-stayed bridge of the Red River is established. The dynamic characteristics of the cable stayed bridge are calculated and analyzed. The results show that the modal distribution of the bridge is dense, and the first fifteen order natural frequency is less than 1Hz..
(2) by using the response spectrum method and dynamic time history analysis method, were analyzed in E1 and E2 of the structure under earthquake and vertical, horizontal and vertical combination of 2 kinds of internal force, displacement and stress response, and comparative analysis of two methods for calculating the seismic response results of the two methods. Show that the E1 bridge in the earthquake, structure is in the elastic state; in the E2 earthquake local pier cracks, meet the basic requirements of minor earthquake, earthquake does not fall.
(3) based on the dynamic time history analysis method, considering the effect of traveling wave on the seismic response of the hybrid girder cable-stayed bridge of the Red River, the longitudinal displacement and internal force of the 4 kinds of wave speed and uniform excitation are compared and analyzed.
(4) the stiffness reduction method is used to simulate the damage of every pier after main shock. The response of the structure under the aftershock is calculated. The displacement and stress changes of the structure under E1 earthquake and E2 earthquake are analyzed and compared. The results show that the aftershock can cause damage to the bridge near the main shock.

【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55;U448.27

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