【作者】 甘露；

【导师】 张亮亮；

【作者基本信息】 重庆大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 斜拉桥属于高次超静定结构,施工方法与成桥后的主梁线形及结构内力状态密切相关。由于各种非确定性因素的影响,致使斜拉桥施工阶段结构的受力变形过程属于一种复杂的随机过程,这使得大跨度斜拉桥的施工控制问题成为一个重要的研究课题。施工控制仿真计算,就是通过合理的模型,采取有效的结构分析方法,对桥梁的成桥受力状态和施工受力状态进行一定精确度的模拟分析过程。无论在实际施工中采用哪种控制理论,采取恰当的施工过程模拟分析方法是保证施工控制精度和施工进展速度的关键。涪陵乌江二桥为一座高低塔斜拉桥,本文以该桥为工程背景,运用大型有限元分析软件Midas/Civil,建立空间有限元模型,对该桥的施工过程进行了分析计算,主要的内容和结论如下:(1)运用最小弯曲能量法结合影响矩阵来确定了该桥的合理成桥状态,取得了较为满意的结果。表明综合考虑这两种理论来确定斜拉桥的目标状态是较为理想的。(2)采用正装迭代法来确定拉索的施工初张索力,并使用最小二乘法原理来修正,取得了良好的效果。通过少数的几次迭代,便可使正装的成桥索力与目标状态基本一致,误差最大1.2%。表明这种方法来确定斜拉桥的施工状态是合理、有效的,而且由于其在选择初始迭代索力上的灵活性,使该方法在运用起来更为方便。(3)从前支点挂篮的结构受力特点出发,分析了挂篮在各种工况下的受力情况;在综合考虑挂篮支点受力和主梁受力安全的前提下,提出了如何确定斜拉索分次张拉力的范围。(4)对于采用悬臂法现浇的桥梁结构,为了使成桥后的线形满足要求,在施工过程中确定节段的立模标高是施工控制的一项重要内容。本文通过计算得到了主梁各节段的立模标高理论值,为施工控制提供了控制的目标值。(5)斜拉桥的施工过程是一个多参数影响的过程,为了在施工中找出控制的主要方向,本文对一些重要的参数进行了敏感性分析,结果表明,梁段重量、初张索力、混凝土收缩徐变对结构的影响最为显著,应在施工过程中对这些参数进行密切关照并严格控制。更多还原

【Abstract】 The cable-stayed bridge is an indeterminate structure with high degrees, the construction method is closely related to the internal forces state and shape of the bridge. Because of the influence of various undefined factors, the structure force and deformation in the construction stage is a complicated stochastic process. So the construction control of large-span cable-stayed bridges becomes an important research subject. The construction control simulation analysis of cable-stayed bridge is an accurate process of simulation analysis the force and deformation of construction and completion stages through reasonable model namely and taking effective structural analysis method. No matter what control theory is used in the actual construction, taking felicitous simulate analysis method is the key to ensure the precision of construction control and the construct progress.The second Wujiang Bridge in Fu Ling is a higher-lower tower cable-stayed bridge, this paper taking this bridge as background, by using large scaled finite element analysis software Midas/Civil to establish dimensional finite element models, analytical calculated the construct process. The main contents and conclusions of this thesis are as follows:(1) The reasonable design state is determined by the minimum bending energy method and cross interaction matrix, the results are satisfactory. It indicates that determine the reasonable design state of cable-stayed bridge comprehensive consideration this two theoretics is an ideal method.(2) The initial cable forces are gained by the forward iteration method, then modified the difference using least square method. The finished cable forces are consistent to that of the target state basically. get through a few of iteration, the maximum error was 1.2%. This indicated determinate the construct state of cable-stayed bridge by it are reasonable and effective.(3) Based on the structural feature of the front-support hanging-basket, analysis the stress under kinds of condition. After comprehensive consideration the stress of the hanging-basket and safety of the main girder, the range of batched tensioning force are determinate.(4) For the structure which constructed using cantilever method, for the sake of the line shape meets requirements, one of the important contents of construction control is confirm the elevation of main beam segments. This paper calculated the theoretical value, it is the target value of construction control.(5) The construction of cable-stayed bridge is a process influencing by several parameter. For the sake of finding the main aspect during the construction control, this paper analysis the sensitivity of some parameters, the result indicates the beam weight, the initial tensioning force, the shrinkage and crape of concrete are prominence, so these parameter must be control strictly during the construction.更多还原