桥梁顶推施工过程受力分析及关键问题研究

发布时间：2018-03-25 02:03

本文选题：桥梁　切入点：顶推施工　出处：《西南交通大学》2014年硕士论文

【摘要】：桥梁顶推施工法因其高度工业化、施工占地少、机具设备简便、施工过程不阻断交通、结构整体性好、设备(模板等)可多次重复使用、施工过程平稳无噪声、施工速度快等优点而被迅速推广应用,在中等跨径的桥梁施工中已体现出较强的竞争力。随着顶推设备的不断创新,顶推法适用范围逐渐扩大,不可避免地会有传统施工中未曾出现过的新问题相伴而生,结合相关文献的阅读以及参与顶推施工现场监控工作所受到的启发,论文主要对顶推施工法的几个关键问题进行探讨,并对钢箱梁在顶推施工过程中关键部位受力进行详细分析研究。 (1)分别从不同的角度对顶推施工进行明确分类,就顶推施工过程中的临时设施起到的作用及其在施工中面临的问题这两个侧面进行讨论,对顶推施工形成多方位的了解与认识。 (2)采用经典解析法和数值解法对顶推过程中主梁的受力进行分析。得到主梁控制内力、支点反力的解析表达式。利用杆系有限元模型对绍兴滨海大桥钢箱梁顶推施工过程进行分析,得到顶推过程中反力、内力、位移等变化规律,并进行参数分析,揭示支点刚度变化以及顶推设备同步顶升量对顶推施工的影响。 (3)针对已经得出的解析表达式,进行数值分析,得到导梁的合理设计参数,并针对导梁线形设计提出控制原则；针对顶推平台梁体脱空时梁体受力安全提出控制原则,以及相应的解决办法与改善措施,以供施工参考。 (4)在介绍了接触问题的分类及其计算方法之后,采用ANSYS建立空间梁-壳-实体-接触混合有限元计算模型,对绍兴滨海大桥顶推过程中最不利工况进行空间应力分析。研究钢箱梁在顶推过程中所承受顶推设备反力的不均匀分配、弹性支座的应力分布、弹性垫层刚度对钢箱梁顶推施工的影响,给出了顶推施工中弹性垫层选择的建议,并分析了梁体横向偏移的影响；将计算结果与现场实测值对比,结果吻合良好。根据计算结果得到钢箱梁在局部反力分布的简化计算公式,以供同类型桥梁顶推施工参考。
[Abstract]:Due to its high industrialization, small construction area, simple equipment and equipment, no interruption of traffic during construction, good integrity of structure, repeated use of equipment (formwork, etc.), the construction process is smooth and noiseless. Because of the advantages of fast construction speed and so on, it has been popularized and applied rapidly, which has shown strong competitiveness in the bridge construction of medium span. With the continuous innovation of the pushing equipment, the scope of application of the thrusting method has gradually expanded. Inevitably, there will be some new problems that have not appeared in the traditional construction, which will be inspired by the reading of the relevant documents and the participation in the monitoring work of the construction site. This paper mainly discusses several key problems in the method of jacking construction, and makes a detailed analysis and research on the stress on the key parts of the steel box girder in the process of jacking construction. 1) categorizing the jacking construction from different angles, discussing the function of temporary facilities in the process of pushing construction and the problems they face in construction, and forming a multi-directional understanding and understanding of the jacking construction. (2) A classical analytical method and a numerical method are used to analyze the force of the main beam in the process of pushing, and the controlled internal force of the main beam is obtained. The analytical expression of the reaction force of the fulcrum. By using the finite element model of the bar system, the jacking construction process of the steel box girder of Shaoxing Binhai Bridge is analyzed, and the law of change of reaction force, internal force and displacement in the process of pushing is obtained, and the parameter analysis is carried out. This paper reveals the influence of the stiffness change of support point and the amount of synchronous lifting of the lifting equipment on the jacking construction. 3) according to the analytical expression obtained, the reasonable design parameters of the guide beam are obtained, and the control principle is put forward for the linear design of the guide beam, and the control principle for the force safety of the beam body when the platform beam is emptied is put forward. And the corresponding solutions and improvement measures for construction reference. (4) after introducing the classification of contact problems and their calculation methods, a hybrid finite element model of space beam-shell-solid contact is established by using ANSYS. The spatial stress analysis of the most unfavorable conditions during the pushing process of Shaoxing Binhai Bridge is carried out. The uneven distribution of the reaction force of the steel box girder and the stress distribution of the elastic support are studied. The influence of elastic cushion stiffness on the jacking construction of steel box girder is presented, the suggestion of selecting elastic cushion in jacking construction is given, and the influence of transverse deviation of beam body is analyzed, and the calculated results are compared with the field measured values. The results are in good agreement with each other. A simplified formula for calculating the local reaction force distribution of steel box girder is obtained, which can be used as a reference for the jacking construction of the same type of bridge.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.462

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