预应力混凝土连续梁桥收缩徐变效应随机分析

发布时间：2018-03-21 03:37

本文选题：连续梁桥　切入点：收缩　出处：《华南理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：预应力混凝土连续梁桥施工复杂,结构体系转换多,易受混凝土收缩徐变影响。影响收缩徐变的不确定性因素众多,造成其长期效应表现出显著随机性。本文结合某三座桥工程实例,采用随机分析方法,考虑影响预应力混凝土连续梁桥收缩徐变的主要随机因素,对预应力混凝土连续梁桥的收缩徐变效应展开随机分析研究。本文主要研究内容包括:(1)广泛搜集国内外关于混凝土收缩徐变研究资料,综合阐述混凝土收缩徐变的产生机理、影响因素及其最新的一些研究进展,并归纳了现有的收缩徐变计算理论。(2)运用正装分析法对三座预应力混凝土连续梁桥进行施工过程仿真分析,得出其在各个施工阶段主梁各节段的应力和位移。(3)考虑影响混凝土收缩徐变效应主要因素的随机性,讨论了结构收缩徐变效应(应力、位移)的随机分析方法,即基于响应面的蒙特卡罗方法,为本文的计算分析提供了理论依据。(4)采用基于响应面的蒙特卡罗方法,分别对某三座预应力混凝土连续梁桥在主梁是否超重情况下的收缩徐变效应(应力、位移)进行了随机分析,获得结构应力和位移的统计特性和基于概率意义的预测结果。(5)结合响应面函数定义了一种随机变量影响程度分析方法,结果分析表明,环境相对湿度的随机性对混凝土收缩徐变效应(应力、位移)变异性的影响程度最为强烈,其次是混凝土抗压强度和加载龄期的随机性,而构件理论厚度和开始收缩龄期的随机性对混凝土收缩徐变效应的影响程度较弱。
[Abstract]:The construction of prestressed concrete continuous beam bridge is complicated, and the structural system conversion is many, which is easy to be affected by concrete shrinkage and creep. There are many uncertain factors affecting shrinkage and creep. In this paper, the main random factors affecting the shrinkage and creep of prestressed concrete continuous beam bridges are considered by means of random analysis method. Random analysis of shrinkage and creep effect of prestressed concrete continuous beam bridge is carried out. The main contents of this paper include: (1) collecting widely domestic and foreign data on shrinkage and creep of concrete, and comprehensively expounding the mechanism of concrete shrinkage and creep. The influencing factors and some recent research progress are summarized, and the existing theory of shrinkage and creep calculation is summarized. The construction process simulation analysis of three prestressed concrete continuous beam bridges is carried out by means of dress analysis method. The randomness of the main beam's stress and displacement at each stage of construction considering the main factors affecting the shrinkage and creep effect of concrete is obtained, and the random analysis method of the structural shrinkage and creep effect (stress, displacement) is discussed. That is, the Monte Carlo method based on response surface, which provides the theoretical basis for the calculation and analysis of this paper, uses the Monte Carlo method based on response surface. The shrinkage and creep effect (stress, displacement) of three prestressed concrete continuous beam bridges under the condition that the main beam is overweight or not is analyzed randomly. The statistical properties of structural stress and displacement and the prediction results based on probabilistic meaning are obtained. A method for analyzing the influence degree of random variables is defined in combination with the response surface function. The results show that, The randomness of environmental relative humidity has the strongest influence on the shrinkage and creep effect (stress, displacement) of concrete, followed by the randomness of compressive strength and loading age of concrete. However, the influence of the theoretical thickness of members and the randomness of the initial shrinkage age on the shrinkage and creep effect of concrete is weak.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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