圆形钢套管加固钢筋混凝土短柱受压性能分析及承载力研究

发布时间：2018-05-31 12:35

本文选题：圆形钢套管加固钢筋混凝土 + 受力性能　；参考：《西南交通大学》2015年博士论文

【摘要】：圆形钢套管因为具有很强的“套箍”能力,优异的力学性能,施工快捷方便,因此受到加固工程领域的广泛应用。但是在以往的研究中,总是将其与钢管混凝土混淆,事实上两者在力学性能上有很大的区别,而目前针对圆形钢套管加固钢筋混凝土柱的相关文献并不多见,加固设计计算也并不令人满意,因此本文的研究工作正是基于这一现状进行的,主要研究内容共有以下8个部分：1.通过圆形钢套管加固钢筋混凝土短柱轴心受压破坏试验,全面研究了加固受压短柱的工作机理：通过对不同设计参数(钢套管厚度、初始应力)的加固试件进行试验及理论分析,得到各种设计参数对圆形钢套管加固钢筋混凝土柱受力性能以及轴心受压承载力的影响关系。2.对圆形钢套管加固钢筋混凝土短柱的轴心受压破坏进行有限元数值模拟,利用数值模拟方法,深入研究了初始应力对加固短柱承载力的影响,比较了一次受力加固短柱与二次受力加固短柱在承载力以及各部分应力、应变的变化规律。3.对4种常见的约束混凝土本构关系进行阐述,利用有限元数值模拟方法,将4种本构关系计算出来的加固短柱承载力与试验结果进行对比,得到最适用于圆形钢套管加固钢筋混凝土的应力-应变关系,为之后的设计计算奠定基础。4.根据加固短柱受力的工作机理,得到新老混凝土结合面竖向荷载的传递长度以及承载力假定条件,基于圆形钢套管加固钢筋混凝土短柱轴心受压力学性能的试验,对加固短柱的轴心受压承载力极限状态进行分析,提出了钢套管“套箍力”与钢套管纵向应力的修正表达式,得到了考虑加固层剪切变形与轴向变形的加固短柱轴心受压承载力计算方法；同时考虑加固前柱已受力的现实状况,提出了临界应力概念,得到了考虑初始应力的加固短柱轴心受压承载力计算方法。5.通过圆形钢套管加固钢筋混凝土短柱偏心受压破坏试验,全面研究了偏心受压加固短柱的工作机理；通过对不同设计参数(钢套管厚度、偏心距)的加固试件进行了试验以及理论分析,得到各种设计参数对圆形钢套管加固偏心受压短柱的受力性能以及偏心受压承载力的影响。6.基于圆形钢套管加固钢筋混凝土短柱偏心受压破坏试验,借鉴钢管混凝土的计算方法,提出了考虑加固层轴向变形与剪切变形的等效紧箍力的概念,得到一次受力加固短柱偏心受压承载力,同时考虑到加固前柱已受力的实际状况,利用叠加法得到考虑初始应力的加固短柱偏心受压承载力计算公式。7.对圆形钢套管加固钢筋混凝土短柱的偏心受压性能进行非线性有限元分析,并将偏心受压加固短柱的一次受力计算承载力与试验承载力进行比较,同时将数值计算结果进行拟合,得到偏心受压加固短柱一次受力的承载力简化公式；利用上述有限元分析方法,深入研究初始应力对偏心受压加固短柱承载力的影响,比较了一次受力加固短柱与二次受力加固短柱承载力以及各部分应力、应变的变化规律。8.通过对圆形钢套管加固钢筋混凝土短柱新老混凝土结合面的研究,得到轴心受压荷载作用下加固短柱结合面受力的工作机理、荷载传递长度以及新老混凝土结合面与锚固钢筋的应力、应变分布规律；同时推导了考虑混凝土收缩、徐变的新老混凝土结合面的剪应力,总结结合面的抗剪强度计算公式,最后根据结合面的破坏形式,得到锚固钢筋的最小配筋率。
[Abstract]:Because of its strong "hoop" ability, excellent mechanical properties and quick and convenient construction, circular steel casing is widely used in the field of reinforcement engineering. However, in the past research, it is always confused with concrete filled steel tube. In fact, there is a great difference in mechanical properties between the two. At present, the circular steel casing reinforcement steel is used to reinforce the steel. The related literature of reinforced concrete columns is not very common, and the calculation of reinforcement design is not satisfactory. Therefore, the research work of this paper is based on this situation. The main contents of this paper are as follows: (1.) the axial compression failure test of reinforced concrete short columns strengthened by circular steel casing has been studied, and the reinforcement of compressed short columns is fully studied. Working mechanism: through the test and theoretical analysis of the reinforced specimens with different design parameters (steel casing thickness, initial stress), the influence of various design parameters on the mechanical properties of reinforced concrete columns reinforced by circular steel casing and the bearing capacity of the axial compression is obtained. The axial compression of the reinforced concrete short column reinforced with circular steel casing.2. The effect of the initial stress on the bearing capacity of the reinforced short column is deeply studied by the numerical simulation method. The bearing capacity, the stress and the strain of each part of the short column reinforced by a reinforced short column and two times are compared, and the relationship between the 4 common constraint concrete constitutive relations is explained by.3.. By using the finite element numerical simulation method, the bearing capacity of the reinforced short column calculated by the 4 constitutive relations is compared with the test results. The stress strain relation of the reinforced concrete reinforced with the circular steel casing is obtained, and the foundation for the later design and calculation is laid on the basis of the working mechanism of the.4. reinforcement of the short column, and the combination of the new and old concrete is obtained. The transfer length of vertical load and the assumption of bearing capacity are discussed. Based on the test of the pressure behavior of reinforced concrete short column with circular steel casing, the ultimate state of the bearing capacity of the reinforced short column is analyzed. The modified expression of the "hoop force" and the longitudinal stress of the steel casing is put forward. The calculation method of the axial compression bearing capacity of the short column with the shear deformation and the axial deformation is taken into consideration. At the same time, the critical stress concept is taken into consideration, and the calculation method of the axial compression bearing capacity of the short column under the consideration of the initial stress is obtained..5. is strengthened by the circular steel casing to reinforce the eccentric compression of the short column of the reinforced concrete column. The working mechanism of the short column reinforced by eccentric compression is comprehensively studied, and the experimental and theoretical analysis of the reinforced specimens with different design parameters (steel casing thickness and eccentricity) are carried out and the effects of various design parameters on the force performance and eccentric compression bearing capacity of the eccentric compression short columns reinforced by circular steel casing are obtained by.6.. The eccentric compression failure test of reinforced concrete short column reinforced with circular steel casing is tested. Using the calculation method of concrete-filled steel tube for reference, the concept of equivalent tightening force considering the axial deformation and shear deformation of the reinforced layer is put forward, and the eccentric compression bearing capacity of a short column reinforced by a force is obtained. At the same time, the actual condition of the reinforcement of the column has been taken into account, and the superposition is made by the superposition. The method of calculating the eccentric compression bearing capacity of reinforced short column with initial stress,.7., is used to analyze the nonlinear finite element analysis of the eccentric compression performance of reinforced concrete short columns reinforced by circular steel casing, and compare the one time bearing capacity of the short column with the eccentric compression reinforced short column with the test bearing capacity, and the numerical calculation results are carried out at the same time. The simplified formula of the bearing capacity of a short column reinforced by eccentric compression is obtained, and the effect of the initial stress on the bearing capacity of the short column reinforced by eccentric compression is deeply studied by using the above finite element analysis method. The bearing capacity of a short column reinforced by a short column and two times of the reinforced short column, and the variation of the stress and strain of each part,.8. pass, are compared. Through the study of reinforced concrete short column new and old concrete bonding surface with circular steel casing, the working mechanism, load transfer length, stress and strain distribution of new and old concrete combined surface and anchored steel bar are obtained under the effect of axial compression loading, and the shrinkage and creep of concrete are derived. The shear stress of the combined surface of the new and old concrete is summarized, and the formula of the shear strength is summed up. Finally, the minimum reinforcement ratio of the anchored steel bar is obtained according to the failure form of the combined surface.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU375.3

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