粘贴加固混凝土弯箱梁桥的方案比选及优化研究

发布时间：2018-10-13 10:31

【摘要】：伴随着我国交通事业的发展,现役桥梁承受着越来越大的交通量,尤其是早期修建的混凝土桥梁目前出现了不同程度的病害和损伤。将这些旧桥全部推倒重建既不合理也不现实,因此,深入开展旧桥加固的研究工作具有重要的意义。本文首先回顾了国内外旧桥加固研究现状,介绍旧混凝土桥常见的病害及其成因,对常见的加固方法与计算原理进行了总结。其次,结合一座火灾损毁桥梁加固前后的荷载试验结果,验证了有限元分析方法的可行性。最后,在此基础上选取某一弯箱梁桥作为加固对象,采用有限元建模计算方法,探讨分析了粘贴不同厚度钢板、不同层数碳纤维布对结构受力性能的影响。研究表明,箱梁底板粘贴钢板或碳纤维布可以显著提高截面弯矩抗力,对裂缝的限制效果也较为明显,但对梁体下挠的抑制作用较弱。箱梁腹板粘贴钢板可以大幅提高其抗剪承载力,且效果较为明显。本文中的弯箱梁匝道桥,在既定的加固目标下,底板粘贴8mm厚的钢板或者1层碳纤维布较为合理;选用腹板斜向45°粘贴8mm厚的钢板条较经济。本文结合工程实例,利用有限元建模计算,分析对比了不同材料用量对弯箱梁桥受力性能的影响,对材料用量进行了优化计算,对旧桥加固工程实践具有一定的参考价值。
[Abstract]:With the development of transportation in our country, existing bridges are suffering more and more traffic, especially the concrete bridges built in the early stage have been damaged and damaged in different degrees. It is neither reasonable nor realistic to push down and rebuild all these old bridges. Therefore, it is of great significance to carry out the research work of strengthening old bridges in depth. This paper first reviews the current situation of the research on the reinforcement of old bridges at home and abroad, introduces the common diseases of old concrete bridges and their causes, and summarizes the common reinforcement methods and calculation principles. Secondly, the finite element analysis method is proved to be feasible by combining the load test results of a damaged bridge before and after strengthening. Finally, a curved box girder bridge is selected as the reinforcement object, and the finite element modeling method is used to analyze the influence of different thickness steel plate and different layers of carbon fiber cloth on the mechanical performance of the structure. The results show that the steel plate or carbon fiber cloth attached to the bottom of the box girder can significantly improve the bending moment resistance of the section, and the effect of limiting the crack is obvious, but the restraining effect on the deflection of the beam body is weak. The shear capacity of box girder webs can be greatly improved by sticking steel plate, and the effect is obvious. For the ramp bridge of curved box girder in this paper, it is reasonable to stick 8mm thick steel plate or 1 layer carbon fiber cloth to the bottom plate under the fixed reinforcement target, and it is more economical to select the steel plate with 8mm thickness attached to the web diagonally 45 掳. In this paper, the influence of different material dosage on the mechanical performance of curved box girder bridge is analyzed and compared by using finite element modeling and calculation combined with engineering example, and the material amount is optimized and calculated, which has certain reference value for the practice of strengthening old bridge.
【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】：U445.72

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