弯坡连续刚构桥收缩徐变影响机理研究

发布时间：2019-01-09 16:51

【摘要】：弯坡连续刚构桥结构形式变化灵活，能够很好的适应复杂地形，因此在高原山区得以广泛应用。但是，由于其复杂的结构形式和弯扭耦合作用等不利因素的影响，也出现了越来越多的问题，例如：主梁裂缝数量比同跨径的直连续刚构桥要多，耐久性低等。为了掌握该类桥型的收缩徐变影响机理，为此类桥梁的设计及安全运营提供有价值的参考，利用数值模拟的方法对该类桥梁的收缩徐变影响机理进行研究。并对弯坡连续刚构桥的力学结构特性进行综合分析，同时研究收缩徐变对其的影响，，总结弯坡连续刚构桥收缩和徐变理论。详细对混凝土收缩徐变的特点、原因机理以及对其影响因素进行阐述，总结分析了各种计算方法的适用范围。以云南某大桥为依托工程研究，采用有限元分析程序对不同曲率半径和纵坡的桥梁建模分析，研究收缩徐变在不同的曲率半径和纵坡下的桥梁结构内力和变形的影响，得出随着曲率半径和纵坡变化时，弯坡连续刚构桥结构内力和变形的变化规律。通过对弹性模量、加荷龄期和相对环境湿度的变化，考虑不同的混凝土抗压强度、加荷龄期以及相对环境湿度对弯坡连续刚构桥的内力和变形的影响，来研究大跨弯坡连续刚构桥收缩徐变的影响机理，得出这些影响因子对弯坡连续刚构桥的影响规律。比较分析不同的收缩徐变预测模型的计算分析结果，得出各自影响的程度大小。基于以上研究分析结果，从桥梁设计、施工和运营养护三方面提出了一些减少收缩徐变对弯坡连续刚构桥影响效应的对策。对研究结果的总结和归纳，并提出了一些建议和展望。
[Abstract]:Curved slope continuous rigid frame bridge structure is flexible, can adapt to complex terrain, so it can be widely used in plateau mountain area. However, due to the influence of the complex structure and the coupling of bending and torsion, there are more and more problems, such as the number of cracks in the main beam is more than that of the straight continuous rigid frame bridge with the same span, and the durability is low. In order to understand the influence mechanism of shrinkage and creep of this kind of bridge and to provide valuable reference for the design and safe operation of this kind of bridge, the influence mechanism of shrinkage and creep of this kind of bridge is studied by means of numerical simulation. The mechanical structure characteristics of continuous rigid frame bridge with curved slope are analyzed and the influence of shrinkage and creep on it is studied. The theory of shrinkage and creep of continuous rigid frame bridge with curved slope is summarized. The characteristics, cause mechanism and influencing factors of concrete shrinkage and creep are described in detail, and the applicable range of various calculation methods is summarized and analyzed. Based on the engineering research of a bridge in Yunnan Province, the influence of shrinkage and creep on the internal force and deformation of bridge structure under different curvature radius and longitudinal slope is studied by using finite element analysis program to model the bridge with different curvature radius and longitudinal slope. With the change of curvature radius and longitudinal slope, the variation of internal force and deformation of curved slope continuous rigid frame bridge is obtained. Through the changes of elastic modulus, loading age and relative environmental humidity, the effects of different compressive strength, loading age and relative environmental humidity on the internal force and deformation of continuous rigid frame bridge with curved slope are considered. To study the influence mechanism of shrinkage and creep of long-span continuous rigid frame bridge with curved slope, and obtain the influence law of these factors on continuous rigid frame bridge with curved slope. The calculated results of different models of shrinkage and creep prediction are compared and analyzed, and the degree of influence is obtained. Based on the above results, some countermeasures to reduce the effect of shrinkage and creep on continuous rigid frame bridge with curved slope are put forward from the aspects of bridge design, construction and operation maintenance. The research results are summarized, and some suggestions and prospects are put forward.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.23

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