多跨钢筋混凝土双肋箱型拱桥加固技术研究

发布时间：2018-09-11 06:54

【摘要】：多跨钢筋混凝土箱型肋拱桥相对其他桥型,具有造型优美、施工方便、造价较低和跨越能力较大等特点,在我国应运十分广泛。但是,在众多建成的多跨钢筋混凝土箱型肋拱桥之中,不少桥梁都出现了不同程度的病害,已经不能满足当今社会交通的需求,因此对多跨钢筋混凝土肋拱桥加固方法进行研究有着重大的意义。本文在汇总了国内外所做的桥梁加固方法研究工作之后,总结了多跨钢筋混凝土箱型肋拱桥常见病害,同时对引起病害的原因进行了分析,然后对该类桥型的加固技术理论和方法进行了深入研究,同时对主要部件的加固技术特点也进行了大量研究工作。本文以藤县西江大桥加固项目为例,在加固前对大桥进行了外观检测、荷载试验、病因分析和内力检算,然后提出对主桥拱肋靠近拱脚三小跨采用增大截面、部分拱上立柱采用增大截面、立柱上盖梁采用黏贴钢板的加固方法进行加固。利用MIDAS/Civil和ANSYS有限元软件建立了藤县西江大桥有限元整体分析模型和局部有限元模型,对全桥进行了内力检算、应力分析以及全桥整体稳定性分析,对盖梁、立柱进行了局部分析。分析结果显示,在加固后恒载作用下,主拱肋弯矩平均增加6.9%,轴力平均增加10.2%。在正常使用各工况下,弯矩和轴力平均增加了 9.2%左右,但拱脚压应力减小了 15.54%,拱顶由拉应力变为压应力,无裂缝产生。加固后局部构件应力均相应减小,其中最大拉应力减小了 29%。加固后桥梁承载能力增加18.4%。同时,桥梁整体稳定性增强。可见加固效果比较理想,为加固维修设计后的可靠性提供了理论数据。在加固完成后,又对藤县西江大桥进行了外观检测和荷载试验,检测结果没有发现新增病害,加固后荷载试验结果表明桥梁承载能力满足设计荷载要求。且第19和20跨在相同荷载试验工况下,挠度分别是加固前的47.1%和68.3%,应变分别是加固前的62.5%和77.2%。加固后刚度、稳定性增强显著,验证了本次加固方案的有效性和可靠性。本文的研究结果能为多跨钢筋混凝土双肋箱型拱桥的加固设计提供一定的参考。
[Abstract]:Compared with other bridges, multi-span reinforced concrete box-ribbed arch bridges have the characteristics of beautiful shape, convenient construction, low cost and large span capacity, which should be widely used in our country. However, among the many multi-span reinforced concrete box rib arch bridges, many bridges have been damaged to varying degrees, which can not meet the needs of social transportation. Therefore, it is of great significance to study the reinforcement method of multi-span reinforced concrete rib arch bridge. After summarizing the research work of bridge reinforcement method at home and abroad, this paper summarizes the common diseases of multi-span reinforced concrete box rib arch bridge, and analyzes the causes of the disease. Then, the theory and method of this kind of bridge reinforcement technology are deeply studied, and a lot of research work is also done on the technical characteristics of the main components. Taking Xijiang Bridge reinforcement project in Fuxian County as an example, the paper carries out the exterior inspection, load test, etiology analysis and internal force check of the bridge before reinforcement, and then proposes to adopt an enlarged section for the arch rib near the arch foot of the main bridge. Part of the arch column is reinforced by increasing section, and the upper cover beam of the column is strengthened by sticking steel plate. The whole finite element analysis model and local finite element model of Xijiang Bridge in Fuxian County are established by using MIDAS/Civil and ANSYS finite element software. The internal force check, stress analysis and overall stability analysis of the whole bridge are carried out. The local analysis of the column is carried out. The results show that the bending moment of the main arch rib increases by 6.9 and the axial force increases by 10.2. Under the normal operation conditions, the bending moment and axial force increase by about 9.2% on average, but the compressive stress of arch foot decreases by 15.54, and the arch top changes from tensile stress to compressive stress, and no cracks occur. After strengthening, the local stress decreases correspondingly, and the maximum tensile stress decreases by 29%. After strengthening, the bearing capacity of the bridge was increased by 18.4. At the same time, the overall stability of the bridge is enhanced. It can be seen that the effect of reinforcement is ideal, which provides theoretical data for the reliability of design of reinforcement and maintenance. After the reinforcement, the external appearance test and load test of Xijiang Bridge in Fuxian County were carried out, and no new diseases were found. The results of the strengthened load test showed that the bearing capacity of the bridge met the design load requirements. The deflection of the 19th and 20th span under the same load test conditions is 47.1% and 68.3% of that before reinforcement, and the strain is 62.5% and 77.2% of that before reinforcement, respectively. The stiffness and stability of the reinforcement are significantly enhanced, which verifies the effectiveness and reliability of the reinforcement scheme. The results of this paper can provide a certain reference for the reinforcement design of multi-span reinforced concrete double-rib box arch bridge.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.72

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