采用组合法施工的钢筋混凝土拱桥徐变收缩影响研究

发布时间：2018-05-05 13:46

本文选题：钢筋混凝土拱桥 + 收缩徐变　；参考：《重庆交通大学》2015年硕士论文

【摘要】：国内大多采用无支架缆索吊装法或劲性骨架法建造大跨度钢筋混凝土拱桥,缆索吊装法虽然降低了节段吊装重量,但存在接头数量多、整体性差的问题;劲性骨架法存在用钢量大、施工时间长、后期徐变收缩大的问题。国外自上世纪60年代起,普遍采用悬臂浇筑法或悬臂浇筑与劲性骨架组合法施工混凝土拱桥,拱圈整体性好、外形美观。采用组合法施工的钢筋混凝土拱桥,拱脚区段采用悬臂浇筑法、拱顶段先用劲性骨架合龙,再围绕劲性骨架外包混凝土,最终形成钢筋混凝土拱。混凝土收缩徐变对以受压为主的钢筋混凝土拱圈的变形和受力有较大影响,迄今为止国内尚未针对采用悬臂浇筑与劲性骨架组合施工的钢筋混凝土拱桥收缩徐变效应影响开展过理论研究。本文依托贵州省交通运输厅科技项目“悬臂浇筑与劲性骨架组合施工大跨度混凝土拱桥技术关键与示范”,以跨径210m的贵州省夜郎湖大桥为研究对象,采用数值分析方法,研究收缩徐变对采用悬臂浇筑与劲性骨架组合施工的钢筋混凝土拱桥主拱圈受力及线形影响:①收集国内外混凝土收缩徐变研究资料,对具有代表性收缩徐变预测模型、徐变计算理论和各种预测模型进行对比分析。总结目前常用的收缩徐变有限元计算分析方法。②运用MIDAS/CIVIL有限元软件,采用D62-2004模型、GL2000模型、NCHRP496模型,开展夜郎湖大桥主拱圈收缩徐变效应分析,对比三种模型计算所得出的施工过程及成桥后主拱圈的变形和应力重分布规律。探讨悬臂浇筑段与劲性骨架不同长度组合下收缩徐变对主拱圈受力及变形影响。③通过D62-2004、GL2000、NCHRP496这三种模型对收缩徐变效应的理论分析研究,给出了三种模型下夜郎湖大桥主拱圈的预拱度值,分析表明,按拱脚推力影响线分配预拱度与拟合的预拱度函数分配方式较为接近。
[Abstract]:In our country, the cable hoisting method or the rigid skeleton method are mostly used to construct the long-span reinforced concrete arch bridge. Although the cable hoisting method reduces the lifting weight of the segment, there are many joints and poor integrity. The stiffness skeleton method has the problems of large amount of steel, long construction time and large creep and shrinkage. Since 1960s, cantilever pouring method or cantilever pouring combined with rigid skeleton method have been widely used in foreign countries to construct concrete arch bridge. The arch ring has good integrity and beautiful appearance. The reinforced concrete arch bridge constructed by combination method is constructed with cantilever pouring method in the arch foot section. The arch section is first closed with a rigid skeleton and then wrapped around the rigid skeleton to form a reinforced concrete arch. The shrinkage and creep of concrete have great influence on the deformation and force of reinforced concrete arch ring which is mainly under compression. Up to now, no theoretical research has been carried out on the effect of shrinkage and creep of reinforced concrete arch bridge constructed by cantilever pouring and rigid skeleton. Based on the scientific and technological project of Guizhou Provincial Communications and Transportation Department, "the key and demonstration of cantilever construction and rigid skeleton combination construction of long-span concrete arch bridge", this paper takes the Yilang Lake Bridge of Guizhou Province with a span of 210 m as the research object, and adopts the numerical analysis method. This paper studies the influence of shrinkage and creep on the main arch ring force and linear shape of reinforced concrete arch bridge constructed by cantilever pouring and rigid skeleton combination. The research data of shrinkage and creep at home and abroad are collected, and the representative shrinkage and creep prediction model is given. The creep calculation theory and various prediction models are compared and analyzed. This paper summarizes the commonly used finite element analysis method of shrinkage and creep by using MIDAS/CIVIL finite element software and using D62-2004 model GL2000 model and NCHRP496 model to analyze the shrinkage and creep effect of the main arch ring of Yilang Lake Bridge. The construction process of the three models and the distribution of deformation and stress of the main arch ring after completion of the bridge are compared. The effects of shrinkage and creep on the stress and deformation of the main arch ring under the combination of cantilever casting section and stiffened skeleton are discussed. 3 the effects of shrinkage and creep on the shrinkage and creep of the main arch ring are studied theoretically by using the three models of D62-2004 and GL2000and NCHRP496. In this paper, the pre-arch values of main arch ring of Yaolang Lake Bridge under three kinds of models are given. The analysis shows that the distribution of pre-arch degree according to the influence line of arch foot thrust is close to the distribution mode of fitting pre-arch function.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.22

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