C70混凝土简支小箱梁抗弯性能分析研究

发布时间：2018-09-03 10:22

【摘要】：高强混凝土的高性能可以满足桥梁工程中对跨径及承载能力等方面的要求,尤其是其表现出现出的高耐久性、良好的工作性、良好的体积稳定性和经济合理性对于桥梁发展现状来说尤为重要。本文针对C70高强混凝土小箱梁的抗弯性能问题,对足尺C70高强预应力混凝土简支梁进行了试验探究,对梁体的受弯破坏形式、承载能力及抗弯性能进行分析。文章试验部分对C70强度等级的混凝土小箱梁进行了抗弯性能的加载试验,并同C50强度等级的试验梁进行抗弯性能的分析对比,对试验梁进行了分析计算和有限元模拟,本文主要内容如下:1)文章的第一部分对高强混凝土在国内外的应用现状以及在应用中出现的问题进行了概述,并提出了本文的研究意义和研究背景,对研究目标和内容进行了总结;2)第二部分提出并研究了试验相关的理论,主要包括使用材料性能、延性、非线性假定及裂缝宽度计算等;对材料试验进行了概述和结果汇总,得出了试验梁所用各种材料的力学参数;3)第三部分对足尺梁加载试验进行了概述,并对各片梁的设计参数、理论计算值、试验梁测点布置和加载方式进行了分析汇总;4)第四部分以桥梁工程中常用的C50强度的预应力混凝土小箱梁作为对照,对C70试验梁加载试验中的两个主要工况(开裂工况和破坏工况)的应变、延性和裂缝等力学行为进行了分析对比,并对C70试验梁的抗弯性能表现进行了评估;5)第五部分对不同预应力设置的C70强度预应力混凝土小箱梁在抗弯性能及梁体力学表现上的影响进行了探讨,分析了截面应变分布情况,对梁的延性及加载试验过程中的裂缝分布及发展情况进行了分析探讨,并进行了部分预应力和全预应力混凝土小箱梁在抗弯性能表现上作出评估。本文以研究C70预应力混凝土小箱梁的抗弯性能为目标,在进行足尺梁加载试验的基础上,文章对C70预应力混凝土小箱梁正常使用状态的安全储备以及极限承载能力等抗弯性能进行了分析,并对加载试验中梁体的力学行为表现进行了分析对比。
[Abstract]:The high performance of high strength concrete can meet the requirements of span and bearing capacity in bridge engineering, especially its high durability and good workability. Good volume stability and economic rationality are very important for bridge development. Aiming at the flexural behavior of C70 high strength concrete small box girder, this paper makes an experimental study on the full scale C 70 high strength prestressed concrete simply supported beam, and analyzes the bending failure mode, bearing capacity and flexural behavior of the beam body. In the experiment part, the flexural behavior of the concrete box girder with C70 strength grade is tested and compared with that of the test beam with C50 strength grade. The test beam is analyzed and calculated and simulated by finite element method. The main contents of this paper are as follows: (1) in the first part of the article, the application status and problems of HSC at home and abroad are summarized, and the research significance and background of this paper are put forward. In the second part, the author puts forward and studies the relevant theories of the test, including the use of material properties, ductility, nonlinear assumption and crack width calculation, and summarizes the material test and the results. The mechanical parameters of all kinds of materials used in the test beam are obtained. In the third part, the loading test of full-scale beam is summarized, and the design parameters of each beam are calculated theoretically. The layout and loading mode of test beams are analyzed and summarized. The fourth part is compared with the small prestressed concrete box girder with C50 strength, which is commonly used in bridge engineering. The mechanical behaviors of strain, ductility and crack in the loading test of C70 test beam under two main conditions (cracking and failure) are analyzed and compared. Finally, the flexural behavior of C70 test beam is evaluated. In the fifth part, the influence of different prestressed concrete box girder with different prestress on the flexural behavior and the mechanical behavior of the beam is discussed. The strain distribution of the section is analyzed, the ductility of the beam and the crack distribution and its development during the loading test are analyzed and discussed, and the flexural behavior of the partially prestressed and fully prestressed concrete small box girder is evaluated. In this paper, the flexural behavior of C70 prestressed concrete small box girder is studied. In this paper, the flexural behavior of C70 prestressed concrete small box girder under normal operation condition, such as safety reserve and ultimate bearing capacity, is analyzed, and the mechanical behavior of the beam in loading test is analyzed and compared.
【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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