葵花拱桥力学特性分析与节点模型试验研究

发布时间：2018-06-07 19:25

本文选题：葵花拱桥 + 矢跨比　；参考：《广州大学》2015年硕士论文

【摘要】：葵花拱桥是一种造型优美、结构新颖的新型桥梁,采用腹拱与主拱连接,取消了传统空腹式拱桥的立柱,外型像是一朵绽放的葵花,因此称之为“葵花拱桥”。由于该桥型结构新颖、受力复杂,与传统的钢筋混凝土拱桥的传力特点有所不同,因此对其受力性能进行深入而系统的研究具有重要的工程意义。本文采用有限元数值分析与模型试验相结合的方法对葵花拱桥全桥的受力特性以及主腹拱连接节点的局部应力状态进行了详细研究,主要完成了以下工作:1、以广州南沙区凤凰二桥为工程背景,采用Midas/Civil和Ansys有限元软件对葵花拱桥的受力性能进行了仿真计算,对比分析了不同矢跨比、不同主腹拱连接方式以及主腹拱连接处不同截面高度对葵花型拱桥结构受力性能的影响。经计算分析可知,葵花拱桥腹拱的矢跨比不宜小于1/6;葵花拱桥主腹拱采用先半铰——后固结的施工方式能有效减少腹拱拱脚负弯矩和拱圈裂缝宽度,对葵花拱桥的结构受力和拱圈抗裂更加有利;主腹拱采用先半铰——后固结的施工方法是一种可行的调整结构应力至合理范围的施工工艺。2、首次设计和制作了葵花拱桥1:5节点试验模型,并在试验模型主拱、腹拱及主腹拱连接处等关键位置布置了钢筋应变、混凝土表面应变和竖向变形测点。模型试验采用千斤顶加载方式,进行了多种工况的静力加载试验,完成了相应的测试工作,获得了葵花拱桥试验模型在各工况下的变形值与各控制截面的应变值。将试验实测结果与有限元计算理论值进行对比分析发现,两者吻合较好,从而验证了有限元数值模型的正确性。3、根据相似理论,通过模型试验结果推导得到桥梁原型结构的应力和位移,并结合葵花拱桥有限元全桥模型计算结果,对比分析表明:原型葵花拱桥在最不利恒载+活载作用下,整体受力性能良好,刚度较大,未发现薄弱部位,有足够的安全贮备。主拱与桥墩结合部位、腹拱与主拱连接部位等关键区域受力性能良好,从而验证了葵花拱桥这类桥型的结构合理性和安全性。
[Abstract]:Sunflower arch bridge is a new type of bridge with beautiful shape and novel structure. It uses belly arch and main arch to connect, cancels the post of traditional hollow arch bridge, and looks like a sunflower in bloom, so it is called "sunflower arch bridge". Because the structure of the bridge is novel and the force is complex, it is different from the traditional reinforced concrete arch bridge in the transmission of force, so it is of great engineering significance to study the mechanical properties of the bridge in depth and systematically. In this paper, the finite element numerical analysis and model test are used to study in detail the stress characteristics of the whole bridge and the local stress state of the connecting joints of the main web arch of the sunflower arch bridge. Taking Phoenix second Bridge in Nansha District of Guangzhou as the engineering background, the mechanical performance of Sunflower Arch Bridge is simulated by Midas / Civil and Ansys finite element software, and the different rise-span ratio is compared and analyzed. The influence of different connecting modes of main web arch and different section height of main web arch on the mechanical performance of sunflower arch bridge. The results of calculation and analysis show that the rise-span ratio of the belly arch of the sunflower arch bridge should not be less than 1 / 6, and that the construction method of the first half hinge and then the consolidation of the main web arch of the sunflower arch bridge can effectively reduce the negative bending moment of the belly arch foot and the width of the crack of the arch ring. It is more favorable to the stress on the structure of sunflower arch bridge and the crack resistance of the arch ring. The construction method of first half hinge and then consolidation of the main web arch is a feasible construction technology of adjusting the structural stress to a reasonable range. The 1:5 node test model of sunflower arch bridge is designed and made for the first time, and the main arch is tested in the test model. Steel bar strain, concrete surface strain and vertical deformation point are arranged at the key position of web arch and main web arch. In the model test, the Jack loading method was used to carry out the static loading test under various working conditions, and the corresponding test work was completed. The deformation values of the model and the strain values of the control sections of the model were obtained under each working condition. By comparing the experimental results with the theoretical values of finite element calculation, it is found that the two results are in good agreement with each other, which verifies the correctness of the finite element numerical model. 3. According to the similarity theory, The stress and displacement of the prototype structure of the bridge are derived from the model test results. Combined with the calculation results of the full bridge model of the sunflower arch bridge with finite element method, the comparison and analysis show that the prototype sunflower arch bridge is under the most unfavorable dead load and live load. The whole force performance is good, the rigidity is big, the weak position has not been found, has the sufficient safety reserve. The combination of the main arch and the pier and the connecting part of the abdominal arch and the main arch have good mechanical performance, which verifies the structural rationality and safety of the sunflower arch bridge of this kind of bridge.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U446

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