混凝土收缩徐变对钢管混凝土拱梁组合结构内力重分布的影响

发布时间：2018-03-22 04:34

本文选题：梁拱组合　切入点：钢管混凝土　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：梁拱组合桥梁以其兼具梁桥和拱桥的受力特点，越来越多的受到桥梁工作者的青睐。近年来，梁拱组合桥梁如雨后春笋出现在桥梁的工程实践中，特别是在大跨度的铁路桥梁，梁拱组合桥梁在安全、适用、经济、美观四个方面都表现了强劲的竞争力。而钢管混凝土拱桥以其同时解决高强材料的应用和施工两大难题，在我国得到了迅速的发展和运用，所以钢管混凝土拱与梁桥的结合在梁拱组合桥梁中使用最多。但钢管混凝土拱梁组合结构在设计理论的研究还远远落后于工程实践，对这种新颖的组合桥梁的结构性能展开研究具有重要的现实指导意义。本文以下承式钢管混凝土拱梁组合桥梁广元嘉陵江双线特大桥为工程背景，利用大型有限元软件Midas/civil对混凝土收缩徐变效应进行全桥模拟分析，研究混凝土收缩徐变对钢管混凝土拱梁组合桥梁结构变形、内力的影响以及对截面应力重分布的影响规律，结果表明： ①主梁挠度在施工阶段受混凝土的收缩徐变影响较大，但成桥后主梁挠度变化很小；钢管混凝土拱肋的挠度在收缩徐变的影响下，变化很小。 ②混凝土的收缩徐变对主梁的内力影响不大，但对钢管混凝土拱肋的拱脚处剪力和弯矩影响很大。 ③全桥混凝土的收缩徐变对主梁的截面纵向应力的影响并不明显，成桥后截面纵向压应力几乎都将出现不断减少的趋势，但应力的改变值和改变比例都不大；管内混凝土的收缩徐变使得钢管混凝土拱发生明显的截面应力重分布，其结果导致钢管截面应力越来越大，管内混凝土截面应力越来越小。开展对钢管混凝土拱梁组合桥梁收缩徐变效应的参数分析，探讨不同桥面系恒载、钢管截面刚度引起收缩徐变效应的不同。桥面系恒载越大，收缩徐变效应越明显；钢管截面刚度不同，，收缩徐变效应也会表现很大差别。
[Abstract]:Beam-arch composite bridges are more and more favored by bridge workers for their characteristics of both beam bridge and arch bridge. In recent years, beam-arch composite bridges have sprung up in the engineering practice of bridges, especially in long-span railway bridges. The beam-arch composite bridge has shown strong competitiveness in four aspects: safety, applicability, economy and beauty, while concrete filled steel tubular arch bridge has been developed and applied rapidly in China because of its simultaneous solution to the two major problems of the application and construction of high-strength materials. Therefore, the combination of concrete-filled steel tube arch and beam bridge is widely used in beam-arch composite bridge, but the research on the design theory of concrete-filled steel tube arch beam composite structure is still far behind the engineering practice. It is of great practical significance to study the structural performance of this novel composite bridge. In this paper, the through concrete filled steel tube arch beam composite bridge Guangyuan Jialing River double-line large bridge is used as the engineering background, the full-bridge simulation analysis of concrete shrinkage and creep effect is carried out by using the large-scale finite element software Midas/civil. The influence of concrete shrinkage and creep on the deformation and internal force of concrete filled steel tube arch beam composite bridge and the influence on the stress redistribution of section are studied. The results show that:. The deflection of the main beam is greatly affected by the shrinkage and creep of concrete in the construction stage, but the deflection of the main beam after completion of the bridge is very small, and the deflection of the arch rib of concrete-filled steel tube is very small under the influence of the shrinkage and creep. (2) the shrinkage and creep of concrete have little effect on the internal force of the main beam, but have great influence on the shear force and bending moment at the arch foot of the concrete filled steel tube arch rib. (3) the effect of shrinkage and creep of the whole bridge concrete on the longitudinal stress of the main beam is not obvious. The longitudinal compressive stress of the section after the completion of the bridge will almost appear a decreasing trend, but the change value of the stress and the proportion of the change are not obvious. The shrinkage and creep of concrete in pipe make the section stress redistribution of concrete filled steel tube arch. The result is that the section stress of steel tube becomes larger and larger, and the stress of concrete section in pipe becomes smaller and smaller. The parameter analysis of shrinkage and creep effect of concrete filled steel tube arch beam composite bridge is carried out, and the difference of shrinkage and creep effect caused by steel tube section stiffness under dead load of different deck system is discussed. The larger the dead load of bridge deck system, the more obvious shrinkage and creep effect is. The effect of shrinkage and creep will be very different with different section stiffness of steel pipe.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.22;U441

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