部分预应力高强混凝土小箱梁极限承载能力试验及理论分析研究

发布时间：2018-11-20 16:34

【摘要】：采用高强混凝土材料和部分预应力技术形成了一种工程适用的结构——部分预应力高强混凝土小箱梁。部分预应力高强混凝土小箱梁利用了高强混凝土抗压强度高、耐久性优异和有效控制截面等特点,能提高梁的承载能力、耐久性和减轻自重。利用部分预应力技术提高了梁正常使用极限状态下的抗裂性能,并且部分预应力技术相比全预应力技术更加有利于梁的延性性能,改善梁的延性性能和耗能能力。因此,部分预应力高强混凝土小箱梁非常适用于重载桥梁。目前,我国对预应力高强混凝土结构已经开展了一定的研究,取得了一些成果。但对于部分预应力高强混凝土小箱梁的研究文献报道较少。本文采用试验研究、理论分析与数值模拟计算相结合的方法,对部分预应力高强混凝土小箱梁的静力荷载作用下的抗弯性能进行了研究。本文以某高速公路工程为研究背景,基于部分预应力混凝土小箱梁的延性、裂缝宽度、变形、极限承载能力等多个方面出发,按照C50、C70混凝土强度等级设计了2片小箱梁,并对其进行足尺模型静载破坏试验,详细地分析小箱梁的受力特点及其在荷载作用下的破坏过程。论文除了破坏荷载试验之外,还采用大型空间三维有限元软件ABAQUS将部分预应力高强混凝土小箱梁按整体式实体模型建模,对梁进行分析计算。鉴于规范采用的线弹性计算所带来的误差,本文根据实测参数采用非线性混凝土的本构关系,双折线钢材的应力应变曲线模型,对梁进行非线性有限元分析计算,并将结果与试验值和规范计算值对比,此外,采用有限条代法基于MATLAB对预应力梁全过程进行分析的结果与试验值验证,得出小箱梁的最终极限承载能力。通过本文的分析可以对相似预应力高强混凝土桥梁的承载力研究以及极限设计计算提供借鉴。
[Abstract]:Using high strength concrete material and partial prestressing force technology, a kind of engineering suitable structure, partially prestressed high strength concrete small box girder, is formed. The small box girder with partially prestressed high-strength concrete has the advantages of high compressive strength, excellent durability and effective control of section, which can improve the bearing capacity, durability and reduce the deadweight of the beam. The partial prestressing technique is used to improve the crack resistance of the beam under the limit state of normal use, and the partial prestress technology is more advantageous to the ductility performance of the beam than the full prestressed technology, and improves the ductility performance and energy dissipation ability of the beam. Therefore, partial prestressed high-strength concrete small box girder is very suitable for heavy-load bridges. At present, the prestressed high-strength concrete structure has been studied and some achievements have been made in our country. However, there are few reports on the research of partially prestressed high-strength concrete small box girder. In this paper, the flexural behavior of partially prestressed high-strength concrete small box girder under static load is studied by means of experimental study, theoretical analysis and numerical simulation. Based on the research background of a highway project, based on the ductility, crack width, deformation and ultimate bearing capacity of the partially prestressed concrete small box girder, two small box girders are designed according to the strength grade of C50C70 concrete. The failure test of full-scale model under static load is carried out, and the stress characteristics of small box girder and its failure process under load are analyzed in detail. In addition to the failure load test, a large-scale three-dimensional finite element software ABAQUS is used to model the partially prestressed high-strength concrete small box girder according to the integral solid model, and the beam is analyzed and calculated. In view of the error caused by the linear elastic calculation adopted in the code, the nonlinear finite element analysis of the beam is carried out according to the constitutive relation of the nonlinear concrete and the stress-strain curve model of the double-folded steel, according to the measured parameters. In addition, the finite strip method based on MATLAB is used to analyze the whole process of the prestressed beam and the test value is verified, and the ultimate bearing capacity of the small box girder is obtained. The analysis in this paper can be used as a reference for the study of bearing capacity and ultimate design calculation of similar prestressed high strength concrete bridges.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441

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