钢管混凝土系杆拱桥收缩徐变效应研究

发布时间：2018-09-13 08:51

【摘要】：随着钢管混凝土拱桥在工程建设中的迅速发展,钢管混凝土的收缩徐变问题被广泛关注。特别地,对于钢管混凝土系杆拱桥,不仅要重视钢管混凝土的收缩徐变效应,普通混凝土的收缩徐变效应也是不容忽视的。因此,有必要对钢管混凝土系杆拱桥的收缩徐变效应进行研究,重点分析收缩徐变对主要受力构件内力、应力和变形的影响。本文主要研究内容如下:(1)以国内外对混凝土、钢管混凝土构件和钢管混凝土拱桥收缩徐变的研究成果为基础,重点了解收缩徐变的基本概念、产生机理和影响因素,以及收缩徐变效应计算理论和分析方法,明确了钢管混凝土系杆拱桥进行收缩徐变效应分析存在的问题,确定了需要研究的目标、内容和方法。(2)针对国内外常用的经典收缩徐变模式,从构造形式、影响因素以及预测精度等方面进行对比分析,探讨了各模式的特点和适用性。根据钢管混凝土系杆拱桥钢管内核心混凝土和普通混凝土的不同特点,结合已有研究成果的归纳分析,推荐了钢管内核心混凝土、普通混凝土(系杆混凝土及桥面系混凝土等)的收缩徐变模式选取方法。(3)结合工程实例,采用推荐的收缩徐变模式,通过建立有限元模型,对钢管混凝土系杆拱桥分别在钢管(普通)混凝土收缩徐变单独作用和钢管(普通)混凝土收缩徐变共同作用下,进行收缩徐变效应分析,明确了考虑收缩徐变作用的重要性。并对比分析了“单独作用”叠加与“共同作用”的计算结果,确定了两者之间的相互关系。(4)针对混凝土收缩徐变效应的影响因素,从收缩徐变模式、施工方法以及构造形式等方面对工程实例进行影响因素分析,探讨了各因素的变化对钢管混凝土系杆拱桥各主要受力构件内力、应力和变形的影响程度。
[Abstract]:With the rapid development of concrete-filled steel tubular arch bridge in engineering construction, the shrinkage and creep of concrete-filled steel tube (CFST) has been paid more and more attention. In particular, for concrete-filled steel tubular tied arch bridge, not only the shrinkage and creep effect of concrete filled steel tube should be paid attention to, but also the shrinkage and creep effect of ordinary concrete should not be ignored. Therefore, it is necessary to study the shrinkage and creep effect of concrete-filled steel tubular tied arch bridge, and analyze the influence of shrinkage and creep on the internal force, stress and deformation of the main members. The main contents of this paper are as follows: (1) based on the research results of concrete, concrete-filled steel tube members and concrete-filled steel tubular arch bridges at home and abroad, the basic concept, mechanism and influencing factors of shrinkage and creep are studied. As well as the calculation theory and analysis method of shrinkage and creep effect, the problems existing in the analysis of shrinkage and creep effect of concrete-filled steel tubular tied arch bridge are clarified, and the research objectives are determined. Contents and methods. (2) in view of the classical shrinkage and creep models commonly used at home and abroad, the characteristics and applicability of the models are discussed in terms of their structural form, influencing factors and prediction accuracy. According to the different characteristics of the core concrete in the steel tube and the ordinary concrete in the steel tube of the concrete-filled steel tubular tied arch bridge, combined with the induction and analysis of the existing research results, the core concrete in the steel tube is recommended. The method of selecting shrinkage and creep mode of ordinary concrete (tie bar concrete and bridge deck concrete etc.). (3) combining with engineering example, adopting the recommended shrinkage and creep model, establishing the finite element model, The shrinkage and creep effects of concrete-filled steel tubular tied arch bridges are analyzed under the action of concrete filled steel tube (ordinary) concrete alone and steel tube (ordinary) concrete respectively, and the importance of considering shrinkage and creep is clarified. The calculation results of "single action" superposition and "joint action" are compared and analyzed, and the relationship between them is determined. (4) according to the factors affecting shrinkage and creep effect of concrete, the model of shrinkage and creep is discussed. The influence factors of construction method and construction form are analyzed, and the influence degree of factors on the internal force, stress and deformation of the main stress components of concrete-filled steel tubular tied arch bridge is discussed.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.22

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