【作者】 姜翔；

【导师】 单德山；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2013， 硕士

【摘要】 连续梁拱组合桥作为一种新兴桥型,将连续梁和拱两种结构体系有机地结合在一起,具有结构刚度大、受力合理、造型美观等特点,适用于软土地基地区的大跨度铁路桥梁建设,在60-200m跨径范围内具有一定的竞争力。但是,围绕连续梁拱组合桥的施工控制研究却相对较少。为此以正在建设中的某连续梁拱组合桥作为工程背景,对采用“先梁后拱”施工方法连续梁拱组合桥的施工控制展开研究,开展了以下工作：(1).阐述梁拱组合桥的产生与发展现状、连续梁拱组合桥的受力特点以及施工方法,重点分析了连续梁拱组合桥的施工控制研究现状；(2).对现有的合理成桥索力和施工索力确定方法进行讨论,在综合比较的基础上,采用最小弯曲能量法初步确定成桥索力,再利用影响矩阵的调值原理进一步修正成桥索力；施工过程中吊杆的初始张拉力则通过正装迭代法确定；最后结合MIDAS/Civil的未知荷载系数功能应用影响矩阵法计算成桥后二次调索的索力调整量。(3).根据主梁施工的特点,采用自适应控制法对主梁线形进行控制。重点讨论了将遗传算法应用到优化BP神经网络的连接权值、阈值的可行性和优越性,在此基础上,利用遗传算法优化的BP神经网络对影响主梁线形的主要参数进行识别,并对梁段的变形做出预测,从而确定主梁各节段的立模标高调整量,实现对主梁的线形控制。(4).分析了拱肋预拱度的影响因素及设置方法,结合背景工程对几种设置方法做了对比分析,选择按拱脚推力影响线分配法确定拱肋预拱度,从而确定拱肋的制造线形。更多还原

【Abstract】 The continuous girder-arch composite bridge was a new bridge type which combined the continuous girder and the arch together. With the advantages of large structural stiffness, reasonable mechanical behavior and attractive shape, the continuous girder-arch composite bridge was especially suitable to the long span railway bridge in the area of soft soil and it had strong competitiveness in the span from60to200m. However, the research on the construction control of this composite bridge is relatively few. Therefore, one certain continuous girder-arch composite bridge still under construction was taken as the engineering background, the construction control method of the continuous girder-arch composite bridge constructed by the method of "girder first and arch late" was researched. The main works were listed as follows:(1). The emergence and development of the continuous girder-arch composite bridge was described, and the mechanical behavior and construction method were briefly introduced. The existing research on construction control of the continuous girder-arch composite bridge was mainly focused on.(2). The existing methods solving the reasonable cable tension at the completed and construction stage were studied. After comprehensive comparing, the minimum bending energy method was used to work out the preliminary cable tension at completed stage, and then the influence matrix method was adopted to adjust the cable tension. The initial tension at construction stage was obtained by forward iteration method. Finally, The unknown coefficient of load method of MIDAS/Civil was used to calculate the cable force adjustment at the completed stage.(3). According to the characteristics of the girder construction, the adaptive control method was used in the geometric alignment control of the girder. The feasibility and advantage of applying the Genetic Algorithm to optimize the connection weights and thresholds of BP Neural Network was mainly focused on. Then the Genetic Algorithm-BP Neural Network was used to identify the main parameter affecting the girder geometric alignment. And the deflection of girder was forecasted. So the formwork erection elevation was determined.(4). The influence factors and the set methods of the arch rib camber were analyzed. Based on the background engineering, several set methods of the camber were compared, and a method was chosen to determine the arch rib camber. So the fabrication geometry of the arch rib was determined.更多还原