钢管混凝土拱桥关键力学性能分析研究

发布时间：2018-05-30 02:47

本文选题：钢管混凝土拱桥 + 稳定性　；参考：《湖南大学》2014年硕士论文

【摘要】：自1990年起我国第一座钢管混凝土拱桥建成后二十余年间，钢管混凝土拱桥在我国发展迅速。然而，钢管混凝土拱桥相关理论落后于实践，我国尚无专门针对钢管混凝土拱桥的规范。本文以广西省来宾市来华大桥为工程背景，基于通用有限元软件ANSYS，主要对钢管混凝土拱桥的稳定性及徐变展开了分析研究。本文的主要内容及结论如下：（1）对钢管混凝土的发展、特点进行了简要的概述，对钢管混凝土拱桥的应用趋势及设计理论进行了介绍，并对钢管混凝土拱桥的数值模拟方法及施工阶段模拟过程进行了详细的介绍。采用ANSYS建立了来华大桥全桥模型，并采用MIDAS建立了全桥模型进行对比。（2）对横撑的形式与刚度、横撑的布置、桥面系刚度等影响稳定性的宏观因素，进行了特征值稳定分析。分析表明：肋间横撑的形式与布置、活载的分布对稳定性影响较大。桥面系刚度对稳定性影响较小，在不改变形式前提下横撑刚度对稳定性影响较小。对于横撑，通过合理布置及形式的选取比增加其刚度对提高稳定性更有效。对影响稳定性的微观因素，如初始缺陷、初应力等进行了考虑双重非线性的极限承载力分析。分析表明：初始缺陷对稳定性的影响较大，但是，在实际工程中拱肋缺陷不能超出规范要求，而当缺陷在规范允许范围内时，其对承载力影响不大。初应力对极限承载能力的不利影响较小，可以忽略。（3）对来华大桥进行了施工阶段及成桥十年徐变分析，并将数值模拟结果与实测数据进行了对比。徐变分析采用了换算模量法及蠕变模拟两种方法。蠕变模拟时，徐变系数采用04公路桥规模式。有效模量法徐变分析分别采用了04公路桥规、CEP-FIP（1990）、CEP-FIP（1978）及欧洲规范EN1992-2模式。最后，对徐变对承载力的影响展开了分析，并对来华大桥进行了考虑施工阶段及十年徐变全过程的极限承载力分析。分析表明：采用不同的徐变模式计算的施工阶段变形结果较接近，运营期间徐变引起了明显的截面应力重分布，不容忽视。初应力及徐变的综合作用对极限承载力有一定的影响，但影响较小。当拱肋存在初始缺陷时，初应力及徐变对承载力的影响略有增大，但对承载力的影响仍然较小，，徐变对承载力的影响可以忽略。
[Abstract]:Since 1990, the first concrete-filled steel tubular arch bridge has developed rapidly in China. However, the theory of concrete-filled steel tubular arch bridge lags behind the practice, and there is no specific specification for concrete filled steel tube arch bridge in China. Based on the general finite element software ANSYS, the stability and creep of concrete-filled steel tubular arch bridge are studied in this paper, based on the engineering background of Laibin Bridge in Guangxi Province. The main contents and conclusions of this paper are as follows: 1) the development and characteristics of concrete-filled steel tube (CFST) are briefly summarized, and the application trend and design theory of CFST arch bridge are introduced. The numerical simulation method of concrete-filled steel tube arch bridge and the simulation process of construction stage are introduced in detail. The full-bridge model of the bridge in China is established by ANSYS, and the model of the whole bridge by MIDAS is compared. (2) the characteristic value stability analysis of macroscopical factors such as the form and stiffness of transverse brace, the arrangement of transverse brace and the stiffness of bridge deck system are carried out. The analysis shows that the form and arrangement of intercostal transverse brace and the distribution of live load have great influence on stability. The stiffness of deck system has little effect on the stability, and the lateral bracing stiffness has little effect on the stability without changing the form. For transverse brace, it is more effective to improve stability by reasonable arrangement and form selection than by increasing its stiffness. The double nonlinear ultimate bearing capacity of the microcosmic factors such as initial defects and initial stresses are analyzed. The analysis shows that the initial defect has a great influence on the stability, but the arch rib defect can not exceed the requirements of the code in the actual engineering, but when the defect is within the allowable range of the code, it has little effect on the bearing capacity. The negative effect of initial stress on ultimate bearing capacity is small and can be neglected. 3) the construction stage of the bridge in China and the creep analysis of the bridge for ten years are carried out, and the numerical simulation results are compared with the measured data. Conversion modulus method and creep simulation method are used in creep analysis. Creep simulation, creep coefficient of 04 highway bridge scale. The method of effective modulus creep analysis is based on the CEP-FIPP (1990) and the European Code (EN1992-2) model, respectively. Finally, the influence of creep on bearing capacity is analyzed, and the ultimate bearing capacity of the bridge in China is analyzed considering the construction stage and the whole creep process of ten years. The analysis shows that the results of deformation in construction stage calculated by different creep modes are close and the stress redistribution of section caused by creep during operation can not be ignored. The combined effect of initial stress and creep has a certain effect on the ultimate bearing capacity, but the effect is small. The influence of initial stress and creep on the bearing capacity is slightly increased when the arch rib has initial defects, but the influence on the bearing capacity is still small, and the effect of creep on the bearing capacity can be neglected.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.22

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