300m悬臂浇筑钢筋混凝土拱桥设计研究

发布时间：2018-07-20 11:59

【摘要】：采用悬浇法修建钢筋混凝土拱桥因其不受地形限制、拱圈整体性好、外型美观而受到桥梁建设者的亲睐,国外采用此法修建的大跨径钢筋混凝土拱桥不在少数。我国目前采用悬浇法施工工艺修建的拱桥仅有5座,跨度最大者也仅有200m(四川溼鱼大桥)。随着超静定结构分析理论的发展,计算机仿真技术的提高,高强材料在拱桥修建中的运用,国内悬浇拱桥跨度会进一步加大,拱桥将成为山区大跨径桥梁的有利竞争者。因此,开展大跨度钢筋混凝土拱桥悬浇技术研究对促进我国桥梁事业的发展具有切实的现实意义和应用基础。本文依托国家自然科学基金资助项目基于多目标优化的悬浇施工混凝土拱桥构形与安全控制的理论与方法,在充分研究国内外钢筋混凝土拱桥设计及施工工艺的基础上,针对目前国内斜拉扣挂悬臂浇筑钢筋混凝土拱桥的不段涌现,对跨径300m的斜拉扣挂悬臂浇筑钢筋混凝土拱桥进行试设计研究。具体研究工作有:1.针对目前大跨度钢筋混凝土拱桥设计和施工现状,提出了实现300m悬浇拱桥的合理结构参数。在进行参数选择时考虑了悬浇拱桥桥型选择特点,并通过对国内外大量已建大跨径钢筋混凝土拱桥数理统计及计算,初步拟定该桥合理矢跨比为1/6;采用悬链线作为其合理拱轴线,并通过穷举法试算拱轴系数,取m=1.988;主拱截面采用目前常用的单箱双室截面。2.阐述了适合确定悬浇拱桥合理成桥状态的相关理论,在此基础上运用Midas-civil对该设计方案进行一次成拱(桥)和考虑施工过程正装迭代分析,以拱桥截面拉压应力为控制目标,对该桥设计方案进行了承载能力极限状态验算。结果表明:该桥设计参数能够满足结构受力安全的要求,拱桥主拱上下缘截面应力均在规范允许的范围之内。3.对悬浇拱桥施工工艺进行了研究,并结合该设计方案实际情况,提出了符合工程实际的施工步骤。在此基础上,在Midas-civil中利用应力平衡法对拱桥施工过程进行正装分析,分析结果表明:对该300m悬浇拱桥施工过程拟定合理,在施工过程中各工况下拱圈截面上下缘截面应力均在规范允许的范围之内,结构受力安全。
[Abstract]:The construction of reinforced concrete arch bridge by suspension pouring method is favored by the bridge builders for its no limitation of topography, good integrity of arch ring and beautiful appearance. The large span reinforced concrete arch bridge built by this method is not uncommon in foreign countries. At present, there are only 5 arch bridges constructed by suspension casting method in China, and the longest span is only 200m (Sichuan Wet Fish Bridge). With the development of statically indeterminate structure analysis theory, the improvement of computer simulation technology and the application of high-strength materials in the construction of arch bridge, the span of overcast arch bridge in China will be further enlarged, and the arch bridge will become a favorable competitor for long-span bridges in mountainous areas. Therefore, it is of practical significance and application foundation to carry out the research on suspension casting technology of long span reinforced concrete arch bridge to promote the development of bridge cause in our country. Based on the theory and method of configuration and safety control of cantilever concrete arch bridge based on multi-objective optimization supported by National Natural Science Foundation, this paper studies the design and construction technology of reinforced concrete arch bridge at home and abroad. In view of the emergence of reinforced concrete arch bridge constructed with cantilever of cable-stayed buckle and suspension in China at present, the experimental design of 300m span reinforced concrete arch bridge with cable-stayed buckle-hanging cantilever is studied. The specific research work is 1: 1. In view of the present situation of design and construction of large-span reinforced concrete arch bridge, the reasonable structural parameters of 300m cantilever concrete arch bridge are put forward. In the process of parameter selection, the characteristics of type selection of suspension arch bridge are considered, and the mathematical statistics and calculation of a large number of long-span reinforced concrete arch bridges built at home and abroad are carried out. The reasonable rise-span ratio of the bridge is 1 / 6, the catenary line is used as its reasonable arch axis, and the coefficient of arch axis is calculated by exhaustive method. This paper expounds the relevant theories suitable for determining the reasonable completion state of the cantilever arch bridge. On the basis of this theory, Midas-civil is used to analyze the design scheme once, and to take the tension and compression stress of the section of the arch bridge as the control objective, considering the construction process. The limit state of bearing capacity of the bridge is checked and calculated. The results show that the design parameters of the bridge can meet the requirements of structural safety, and the stress of the upper and lower edge section of the arch is within the allowable range of the code. In this paper, the construction technology of suspension arch bridge is studied, and combined with the actual situation of the design scheme, the construction steps in accordance with the engineering practice are put forward. On this basis, the stress balance method is used to analyze the construction process of the arch bridge in Midas-civil. The analysis results show that the construction process of the 300m cantilever cast-in-place arch bridge is reasonable. In the construction process, the stress of the upper and lower edge section of the arch ring section is within the allowable range of the code, and the structure is safe.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.22

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