单索面混凝土斜拉桥牵索挂篮设计与施工工艺研究

发布时间：2018-02-14 07:26

本文关键词： 桥梁工程斜拉桥单索面牵索挂篮设计施工　出处：《郑州大学》2014年硕士论文　论文类型：学位论文

【摘要】：斜拉桥是一种组合式桥梁，，它具有梁体受压、斜拉支撑受拉的特点。它发挥了拉索抗拉能力强，混凝土梁（或钢箱梁）抗压能力大的特点，因其跨度大，整体刚度大，在大跨径桥梁中得到了较好的应用。斜拉桥便于采用悬臂法施工，但由于拉索与主梁和索塔连接构造复杂，且三者之间的内力和变形相互关联性十分密切，因而施工难度高。为了保证桥梁施工过程及最终成桥线形和内力符合设计要求，须在施工前撰写完善的施工步骤和监控方案。本文以肇庆市阅江大桥为研究对象，对单索面斜拉桥施工中的关键技术进行了分析研究，完成了以下工作并得出重要结论。（1）根据阅江大桥的特点，采用挂篮施工分段浇筑主梁混凝土方法。利用有限元软件ANSYS对主梁中央单索面挂篮在四种施工工况下进行了受力分析和变形计算，得出各工况下主要构件的应力及变形结果，根据计算结果设计挂篮截面，并选择合适的钢材。（2）根据阅江大桥的结构特点及现场情况，挂篮安装采用整体提升方法，并制定了详细的操作步骤。挂篮安装后进行了静载试验，试验以挂篮浇筑最重节段混凝土荷载的1.10倍作为最大荷载，采用堆麻袋装砂的加载方式，辅以腹板位置加堆钢筋来模拟主梁混凝土浇注全过程，据此得出挂篮的非弹性变形和弹性变形，前者已经消除，后者通过预抬标高来予以调整。（3）本文详细介绍了主梁及斜拉索的施工工艺及流程，详细阐述了牵索挂篮的特点、牵索挂篮施工工艺流程、挂篮行走与定位、模板工程、钢筋预应力工程、预埋件施工、混凝土工程、斜拉索施等施工工艺。通过对以上内容的研究与分析，得出如下重要结论：（1）箱梁两侧斜腹板及翼缘板下方采用桁架式支承结构，既满足了强度和刚度需要，同时减少了整个挂篮的下部结构重量，使用起来更加轻便；同时两侧桁架与主梁结构采用销轴连接，方便了现场拆装。（2）前支点牵索结构为双向可调节系统，有更强的通用性。可以适应空间三个方向均有一定倾斜度的斜拉索的牵引和张拉。（3）本挂篮前、后支点及锚杆处均采用40CrMo材质的拉杆，避免了采用精轧螺纹钢容易发生脆断破坏的风险。
[Abstract]:The cable-stayed bridge is a kind of composite bridge, which has the characteristics of the beam body being compressed and the cable-stayed support subjected to tension. It exerts the characteristics of strong tensile ability of the cable and great compressive capacity of the concrete beam (or steel box girder), because of its large span and large overall stiffness. The cable-stayed bridge is easy to be constructed by cantilever method, but because of the complex structure of cable, main girder and cable tower, the internal force and deformation of the three bridges are closely related. Therefore, the construction is very difficult. In order to ensure that the bridge construction process and the final completion of the bridge alignment and internal force meet the design requirements, it is necessary to write the perfect construction steps and monitoring scheme before construction. Taking Huijiang Bridge in Zhaoqing City as the research object, this paper analyzes and studies the key technology in the construction of single cable plane cable-stayed bridge, accomplishes the following work and draws important conclusions. 1) according to the characteristics of Huijiang Bridge, the concrete construction method of main girder is adopted in the construction of hanging basket. The stress analysis and deformation calculation of single cable surface hanging basket in the center of main girder under four construction conditions are carried out by using finite element software ANSYS. The results of stress and deformation of the main components under various working conditions are obtained. According to the calculation results, the section of the hanging basket is designed, and the appropriate steel is selected. 2) according to the structural characteristics and site conditions of Yujiang Bridge, the hoisting method is adopted and the detailed operation steps are worked out. The static load test is carried out after the installation of the hanging basket. The maximum load is 1.10 times of the heaviest section concrete load, the loading mode of sand-filled sack is adopted, and the whole process of pouring main beam concrete is simulated with web plate position and pile reinforcement. The inelastic deformation and elastic deformation of the hanging basket are obtained, the former has been eliminated, and the latter is adjusted by raising the elevation. This paper introduces the construction technology and flow of main beam and stay cable in detail, expounds in detail the characteristics of pulling cable hanging basket, the construction process flow, walking and positioning of hanging basket, formwork engineering, reinforcement prestressing force engineering, construction of embedded parts, etc. Concrete engineering, cable-stayed cable construction technology. Through the research and analysis of the above contents, the following important conclusions are drawn:. 1) the truss supporting structure is adopted under the inclined web and flange plate of both sides of the box girder, which not only meets the need of strength and stiffness, but also reduces the weight of the lower structure of the whole hanging basket and is more convenient to use. At the same time, both sides of the truss and the main beam structure are connected by pin shaft, which facilitates the field disassembly and assembly. The structure of the front fulcrum is a bidirectional adjustable system, which is more versatile and can adapt to the traction and tensioning of cables with certain inclination in all three directions of space. 3) in front of the hanging basket, 40CrMo pull rod is used at the rear fulcrum and anchor, which avoids the risk of brittle fracture of finish rolled rebar.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.4;U448.27

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