铁路大跨度劲性骨架混凝土拱桥施工阶段稳定性研究

发布时间：2018-04-27 13:56

本文选题：拱桥 + 劲性骨架　；参考：《西南交通大学》2015年硕士论文

【摘要】：劲性骨架混凝土拱桥兼有钢管混凝土拱桥和钢筋混凝土拱桥的优点,尤其是其施工过程中的自架设系统为施工带来了极大的方便,为拱桥向大跨径发展提供了一个很好实现路径。全文在结构和内容上分为以下两个部分：第一部分简要回顾了钢管混凝土劲性骨架结构的发展历程,介绍了有关拱桥的稳定概念及其分类,总结了钢管混凝土劲性骨架拱桥稳定问题的研究现状。然后简要介绍了桥梁结构几何非线性分析理论,阐述了拱桥的平面屈曲失稳和侧倾失稳的基本理论和圆弧形拱桥的临界荷载解析计算式,对桥梁弹性稳定性分析中的有限单元法进行了简要的论述和公式推导。第二部分以某主跨为445m的上承式高速铁路钢管混凝土劲性骨架拱桥为研究对象,运用MIDAS/CIVIL软件,建立有限元分析模型,研究其施工过程静力力学行为、稳定性及成桥稳定影响因素。主要得出以下结论：(1)在给定施工方案下,施工阶段结构稳定系数最低出现在拱圈腹板浇筑阶段,施工时须密切注意该阶段结构的稳定问题；弦杆内、外侧腹杆在施工过程中应力较大,施工时须注意防止其发生局部失稳；扣索索力对钢骨架吊装阶段结构的稳定影响较大,待骨架合拢后,索力大小对结构稳定性影响不明显,但对结构内力和变形调整有较大影响；整个施工阶段结构第一类稳定系数均大于4,说明在本文论及的施工方案下,结构在施工过程中是安全的；几何非线性在成桥后对结构受力影响不明显,基本可以不用考虑它对结构受力的影响。(2)成桥后,宽跨比、温度效应、上部结构刚度、固定支座安置位置、核心混凝土刚度折减等因素均对结构稳定有影响。就此桥而言,宽跨比对结构稳定影响最为明显。在宽跨比一定时,箱室宽度分布对成桥稳定影响不明显,箱室宽度分布对结构稳定的影响随宽跨变化而变化,箱室宽度分布须考虑施工阶段结构稳定性。温度效应、上部结构刚度、固定支座安放位置、核心混凝土刚度折减等因素对结构的稳定影响不明显。
[Abstract]:The rigid skeleton concrete arch bridge has the advantages of both the concrete arch bridge and the reinforced concrete arch bridge. Especially, the self erection system in the construction process brings great convenience to the construction and provides a good way for the arch bridge to develop to the large span. The full text is divided into two parts in the structure and internal capacity: the first part is simple. The development course of the stiffening skeleton structure of concrete filled steel tube is reviewed, the concept and classification of the stability of the arch bridge are introduced, and the research status of the stability of the rigid frame arch bridge of the concrete filled steel tube is summarized. Then the geometric nonlinear analysis theory of the bridge structure is briefly introduced, and the base of the plane buckling and the lateral instability of the arch bridge is expounded. This theory and the analytic calculation formula of the critical load of arc arch bridge are briefly discussed and formula derivation for the finite element method in the analysis of the elastic stability of the bridge. In the second part, a concrete filled steel tube rigid skeleton arch bridge of a high speed railway with a main span as 445M is taken as the research object, and the finite element analysis is established by using the MIDAS/CIVIL software. The following conclusions are drawn as follows: (1) under the given construction scheme, the structural stability coefficient of the construction stage is the lowest in the stage of arch ring placement, and the stability of the structure must be paid close attention to in the construction period; in the chord bar, the outside belly is in the construction. In the process of high stress, it is necessary to pay attention to prevent local instability in construction. The cable force has great influence on the stability of the structure of the steel frame hoisting stage. After the frame closure, the cable force size has no obvious influence on the structural stability, but it has great influence on the structural internal force and deformation adjustment; the first kind of stability coefficient in the whole construction stage is all of the stability coefficient. More than 4, it shows that under the construction scheme discussed in this paper, the structure is safe during the construction process; the effect of the geometric nonlinearity on the structural stress is not obvious after the completion of the bridge. (2) after the bridge, the width span ratio, the temperature effect, the superstructure stiffness, the placement position of the fixed support, the core concrete stiffness. The width span distribution has no obvious effect on the stability of the bridge, and the width distribution of the chamber width varies with the width span, and the width distribution of the chamber must take into account the stability of the construction stage. The influence of the stiffness, the location of the fixed bearing, the reduction of core concrete stiffness on the stability of the structure is not obvious.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445;U448.22

【参考文献】