T梁体外预应力加固技术的优化研究

发布时间：2018-01-19 12:34

本文关键词： 体外预应力加固简支T梁工程实践有限元模拟　出处：《武汉工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：中小跨径桥梁是公路交通路网的重要组成部分,这些桥很多都年代久远,由于环境、设计、施工及维修等方面的原因,出现了不同程度的破坏,保证它们的安全性能具有重要的经济意义和社会意义。体外预应力属于一种主动加固的范畴,对原结构损害程度低,且能很大程度上提高结构承载能力,有效控制结构跨中挠度及截面裂缝,进而在工程中得到广泛应用。本文以跨径、混凝土等级、预应力筋(束)的截面面积、预应力筋(束)锚固点和转向点为变量,对普通钢筋混凝土简支T型梁桥采用折线形体外预应力加固后的承载能力、梁跨中竖向永久变形和梁跨中混凝土法向正应力进行理论分析和有限元模拟分析。理论结果表明:体外预应力加固能很大程度提高原梁体的抗弯承载力,提高程度随预应力筋(束)面积的增加基本呈线性增长;抗剪承载力与预应力筋(束)的布置情况有关;跨中挠度和截面应力都能有所改善且都控制在规范限制范围内。有限元建模分析结果与理论计算结果基本一致。通过两种方法对比分析,得出用有限元建模分析可以简化计算且结果无较大差异,今后可多应用在体外预应力加固验算中。本文得出的结论,为进一步推广体外预应力加固技术,及其在中小跨径的低等级普通钢筋混凝土T型梁桥加固中的应用提供参考和依据。
[Abstract]:Medium and small span bridges are an important part of highway traffic network. Many of these bridges are old, due to the environment, design, construction and maintenance and other reasons, there have been varying degrees of damage. It is of great economic and social significance to ensure their safety performance. External prestressing belongs to the category of active reinforcement, which has low damage to the original structure and can improve the bearing capacity of the structure to a great extent. Effective control of the mid-span deflection and cross-section cracks, and then widely used in engineering. This paper based on the span, concrete grade, the section area of prestressed tendons (bundles). The anchoring point and turning point of prestressed tendons (bundles) are variables, and the load-carrying capacity of T-beam bridges with simply supported reinforced concrete is strengthened by prestressed concrete. The vertical permanent deformation of beam span and the normal normal stress of concrete in beam span are analyzed theoretically and simulated by finite element method. The theoretical results show that the external prestressed reinforcement can greatly improve the flexural bearing capacity of the original beam. The degree of improvement increases linearly with the increase of the area of prestressed tendons (bundles). The shear bearing capacity is related to the arrangement of prestressed tendons (bundles); The mid-span deflection and cross-section stress can be improved and controlled within the limit range of the code. The results of finite element modeling and theoretical calculation are basically consistent. The results are compared and analyzed by two methods. It is concluded that the finite element modeling and analysis can simplify the calculation and there is no significant difference in the results. In the future, it can be used in the external prestressing reinforcement checking calculation. The conclusion of this paper is to further promote the external prestressing reinforcement technology. And its application in the reinforcement of low grade ordinary reinforced concrete T-beam bridge with medium and small span provides reference and basis.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72

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