大跨高速铁路矮塔斜拉桥静动力研究

发布时间：2018-05-21 06:17

本文选题：高速铁路 + 矮塔斜拉桥　；参考：《西南交通大学》2017年硕士论文

【摘要】：矮塔斜拉桥在我国是一种较晚出现的桥型,但因为施工方便、刚度大、抗震性能良好等优点,在我国得到了快速发展,尤其是在高速铁路桥中,既满足了刚度的需求又增加了桥梁的跨度。我国是地震多发区,加上矮塔斜拉桥出现较晚,故对于该桥型的研究还不够全面和深入,本论文以沅江矮塔斜拉桥为工程背景,利用有限元软件MIDAS/CIVIL建立三维模型,对结构进行静力和动力特性两个方面进行研究,得到如下结论:(1)模拟桥梁整个施工过程,对桥梁最大悬臂阶段和成桥阶段进行内力和应力分析,验算在成桥运营阶段结构应力分布、验算列车活载下主梁挠度情况,均满足规范要求。(2)选取在施工和成桥阶段的十种参数变量,研究各参数对结构主梁的位移、内力以及索力影响,得到各参数对桥梁结构的影响主次情况,保证施工安全可靠。(3)通过对桥梁进行反应谱分析,对比了欧洲规范和国内规范对地震效应的组合方式,发现两种组合的结果非常接近,在计算时可相互验证结果的准确性。(4)将反应谱和时程的结果进行分析对比,得到两种方法的优缺点和使用范围。采用相对位移法对结构进行非一致激励,发现在行波效应中,随着波速的增大,其位移和内力的结果趋近于一致激励的结果。(5)对边界条件进行非线性分析,确定摩擦减震支座的最优参数为R=6m、u=0.07,发现设置减震支座时,桥墩位移和内力有较大的减少,隔震性能良好;采用减震支座对桥梁结构进行全桥隔震和连续墩隔震两种方式进行布置,在考虑经济性时,可采用只在连续墩设置减震支座的方式。(6)通过对桥墩进行材料非线性分析,计算桥墩在最不利荷载下的屈服状态,得到桥墩在设计地震下均处于弹性状态,在罕遇地震下中墩底截面屈服,在设置减隔震支座后,桥墩不会发生大的破坏。
[Abstract]:The low tower cable-stayed bridge is a late type of bridge in our country, but it has been developed rapidly in our country, especially in high-speed railway bridge, because of the advantages of convenient construction, large stiffness and good seismic performance. It not only meets the demand of stiffness but also increases the span of bridge. China is an earthquake prone area, and the cable-stayed bridge with low tower appears late, so the research on this bridge is not comprehensive and deep enough. This paper takes Yuanjiang low tower cable-stayed bridge as the engineering background, using finite element software MIDAS/CIVIL to establish three-dimensional model. The static and dynamic characteristics of the structure are studied. The conclusions are as follows: 1) the whole construction process of the bridge is simulated, and the internal forces and stresses of the maximum cantilever stage and the completion stage of the bridge are analyzed. The structural stress distribution in the operation stage of the bridge is checked, and the deflection of the main beam under the live load of the train meets the requirements of the specification.) Ten parameter variables are selected in the construction and completion stages to study the displacement of each parameter to the main beam of the structure. Under the influence of internal force and cable force, the influence of each parameter on bridge structure is obtained, which ensures the safety and reliability of construction. By analyzing the response spectrum of bridge, the combination mode of seismic effect between European code and domestic code is compared. It is found that the results of the two combinations are very close. The accuracy of the results can be verified by each other in the calculation. (4) the results of the reaction spectrum and the time history are analyzed and compared, and the advantages and disadvantages of the two methods and the scope of their application are obtained. The relative displacement method is applied to the non-uniform excitation of the structure. It is found that in the traveling wave effect, with the increase of the velocity of the wave, the results of displacement and internal force approach to the result of uniform excitation. The optimum parameter of frictional shock absorber is R ~ (6) m ~ (U) ~ (0. 07). It is found that the displacement and internal force of bridge pier are greatly reduced and the isolation performance is good. The whole bridge isolation method and the continuous pier isolation method are used to arrange the bridge structure. When considering the economy, the method of setting the shock absorber support only in the continuous pier can be used to analyze the material nonlinearity of the bridge pier. By calculating the yield state of the pier under the most unfavorable load, it is concluded that the pier is elastic under the design earthquake, and the bottom section of the pier is yielding under the rare earthquake, and the pier will not be destroyed greatly after the isolation support is installed.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.27

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