钢管混凝土拱桥拱肋脱空机理和相关结构稳定性影响研究

发布时间：2018-11-16 18:58

【摘要】：钢管混凝土拱桥作为一种常见桥型，具有承载力高、延性好、施工方便等诸多优点，在桥梁建设中占有重要位置。但在实际工程应用中，该类桥梁也出现诸多问题。其中，拱肋脱空作为最典型病害之一被暴露出来，给拱桥结构受力等各方面性能带来不利影响。对拱肋脱空机理分析以及研究脱空对结构的的承载力和稳定性的影响，对解决脱空病害，提高结构性能等都具有重要的意义。对拱肋脱空机理理论分析需要先确定导致脱空的原因，再对各因素下的脱空进行理论推导，得到脱空解析值。考虑脱空对结构的稳定性影响，需要先系统理解钢管混凝土拱桥的受力特性、稳定分析理论基础上，再将拱肋处于完全粘结状态和全脱空状态时的结构稳定性性能进行对比分析。论文在提出拱肋脱空概念后，主要研究了钢管混凝土拱桥脱空产生的原因，并通过平面应力理论，推导拱肋界面拉应力和脱空高度的计算公式，，进而对各个因素下的脱空机理进行定量分析。以郑州黄河二桥为工程背景，在构建钢管与混凝土粘结-滑移本构模型和采用合理的模拟拱肋方法的基础上，分别建立完全粘结和全脱空两种状态下的ANSYS空间有限元模型。对脱空状态下的结构稳定性分析的主要内容包括拱肋的几何变形、拱桥结构的失稳形态、稳定系数以及结构的动力特性，并将结果与完全粘结状态的稳定性能作对比。此外，脱空对于拱桥稳定性影响与拱肋含钢率、孔洞率和脱空位置等参数有关。本文采用有限元分析方法对这些因素做具体分析，为以后解决钢管混凝土脱空问题提供参考和依据。
[Abstract]:Concrete-filled steel tubular arch bridge, as a common bridge type, has many advantages such as high bearing capacity, good ductility, convenient construction and so on, so it occupies an important position in bridge construction. But in the practical engineering application, this kind of bridge also has many problems. As one of the most typical diseases, arch rib detachment is exposed, which has adverse effects on the performance of arch bridge structure. It is of great significance to analyze the mechanism of arch rib cavitation and to study the influence of the void on the bearing capacity and stability of the structure. It is of great significance to solve the void disease and improve the performance of the structure. For the theoretical analysis of the mechanism of arch rib void, it is necessary to determine the cause of the void first, and then to deduce the void under various factors, and obtain the void analytic value. Considering the influence of emptying on the stability of the structure, it is necessary to systematically understand the mechanical characteristics of concrete-filled steel tubular arch bridge, and based on the stability analysis theory, Then the stability of arch rib in the state of complete bond and full detachment is compared and analyzed. After putting forward the concept of arch rib void, this paper mainly studies the causes of the void of concrete-filled steel tube arch bridge, and deduces the formula of the tension stress and the height of void in the arch rib interface through the plane stress theory. Furthermore, the mechanism of void removal under various factors is quantitatively analyzed. Based on the construction of bond-slip constitutive model of steel pipe and concrete and the reasonable method of simulating arch rib, the ANSYS spatial finite element model under two conditions of complete bond and total void is established. The main contents of structural stability analysis under void condition include geometric deformation of arch rib, instability form of arch bridge structure, stability coefficient and dynamic characteristics of structure. The results are compared with that of complete bond state. In addition, the influence of void on the stability of arch bridge is related to the steel content of arch rib, the porosity and the location of void. In this paper, the finite element analysis method is used to analyze these factors in order to provide reference and basis for solving the problem of concrete filled steel tubular (CFST) voids in the future.
【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】：U448.22;U441

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