连续刚构桥施工控制理论分析与运用

发布时间：2019-03-25 08:04

【摘要】：连续刚构桥以强度高、线形明快、施工简便快捷、跨越能力强的优势在大跨度桥梁中具有广泛的应用。连续刚构桥常常采用对称悬臂浇筑法施工。在悬臂施工过程中，桥梁结构受多种因素的影响，如混凝土的收缩和徐变、设计参数与实际数值的差异、施工误差、测量误差、温度变化等，因此采用悬臂浇筑法施工必然给桥梁结构带来非常复杂的内力和位移变化。为了保证桥梁施工质量和桥梁建设安全，确保连续梁桥成桥后的主梁线形和结构内力符合设计要求，使连续刚构桥的实际状态与设计状态尽可能相符，桥梁施工控制是不可缺少的。本文在分析总结国内外大跨度预应力混凝土连续刚构桥发展和施工控制技术的基础上，对连续刚构桥施工控制的特点以及方法进行概括介绍。以大渡河大山水电站省道S211及库周交通复建工程什月河大桥为工程背景，阐述了灰色系统理论，建立预测模型GM(1,1),将什月河大桥实际工程看成一个灰色系统，以什月河大桥5号墩中跨的9号块箱梁的预测计算为实例，运用GM(1,1)模型对9号块挠度变化值进行预测计算，，得出下一阶段立模板时的预留拱度。本文结合什月河大桥实际工程，运用MIDAS/CIVIL模型软件对参数进行分析计算，得到混凝土的弹性模量与容重的变化对该桥的标高影响最为显著，在弹性模量和容重分析参数减小10%的条件下，引起桥梁挠度值变化范围达到15%左右。采用大型计算软件MIDAS/CIVIL对全桥逐段悬臂施工进行仿真分析模拟，对施工各个阶段进行调整控制。在线形控制中，通过对模型分析计算，得到了施工预拱度与成桥预拱度值，提出了立模标高的计算公式，从合拢结果来看达到了设计的线形，说明了计算结果的正确性。在应力控制中，由模型计算得到了施工各阶段的箱梁理论应力值，经过比较分析，实测应力值与理论应力值基本吻合，达到了对该桥应力控制的目的。根据实际工程经验得出一些关于连续刚构桥有益的结论和经验，为以后相同类型的桥梁施工控制具有一定的借鉴作用。
[Abstract]:Continuous rigid frame bridge has been widely used in long span bridges because of its advantages of high strength, quick alignment, simple construction and strong span ability. Continuous rigid frame bridges are often constructed by means of symmetrical cantilever casting. In the course of cantilever construction, bridge structure is affected by many factors, such as shrinkage and creep of concrete, difference between design parameters and actual values, construction error, measurement error, temperature change and so on. Therefore, the cantilever casting method will inevitably bring complex internal force and displacement change to the bridge structure. In order to ensure the quality of bridge construction and the safety of bridge construction, the alignment and internal force of the main beam after the continuous beam bridge is completed meet the design requirements, and the actual state of the continuous rigid frame bridge accords with the design state as much as possible. Bridge construction control is indispensable. On the basis of analyzing and summarizing the development and construction control technology of long span prestressed concrete continuous rigid frame bridge at home and abroad, this paper briefly introduces the characteristics and methods of construction control of continuous rigid frame bridge. Taking the Dadu River Dashan Hydropower Station provincial road S211 and Shiyuehe Bridge as the engineering background, this paper expounds the grey system theory, establishes the forecasting model GM (1,1), and regards the actual project of Shiyuehe Bridge as a grey system. Taking the prediction calculation of 9 box girder in the middle span of No. 5 pier of Shiyuehe Bridge as an example, the GM (1,1) model is used to predict the deflection value of Block 9, and the reserved camber of the formwork is obtained in the next stage. In this paper, according to the actual project of Shiyuehe Bridge, the parameters of the bridge are analyzed and calculated by using MIDAS/CIVIL model software. The results show that the change of elastic modulus and bulk density of concrete has the most significant influence on the elevation of the bridge. When the analytical parameters of elastic modulus and bulk density are reduced by 10%, the variation range of bridge deflection is about 15%. The large-scale calculation software MIDAS/CIVIL is used to simulate the cantilever construction of the whole bridge segment by section and adjust and control each stage of the construction. In the linear control, the pre-arch degree of construction and the pre-arch value of the bridge are obtained by analyzing and calculating the model, and the formula for calculating the standard height of vertical formwork is put forward. The alignment of the design is achieved from the closing result, and the correctness of the calculation result is explained. In the process of stress control, the theoretical stress values of box beams in each stage of construction are obtained by model calculation. Through comparison and analysis, the measured stress values are basically consistent with the theoretical stress values, and the purpose of stress control of the bridge is achieved. Based on the practical engineering experience, some useful conclusions and experiences about the continuous rigid frame bridge are drawn, which can be used for reference for the construction control of the same type of bridge in the future.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.4

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