高速铁路预应力混凝土槽形梁落架过程研究

发布时间：2018-03-18 16:55

本文选题：槽形梁　切入点：落架顺序　出处：《兰州交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文针对某高速铁路预应力混凝土槽形连续梁桥在施工过程中遇到的落架施工顺序选择的问题进行了研究。施工现场存在环境复杂、施工控制不到位、施工管理不当等因素,无法做到各跨同步卸落。本文通过分析槽形梁因为非同步卸落支架可能出现的各种工况下的受力情况,确定了一种满足施工环境限制的合理落架方案。主要工作如下:(1)探讨了槽形连续梁桥的常用施工方法,并详细探讨了满堂支架法施工槽形连续梁桥的落架问题。(2)分析了槽形梁桥在落架过程中可能出现的问题。通过分析得出了纵桥向和横桥向非同步卸落时槽形梁的受力情况,以及可能出现的不利于结构安全的工况。(3)利用Midas Civil建立落架过程分析的有限元模型。本文按照顺桥向和横桥向的不同落架顺序区分出8种工况,使用梁板结合单元模拟槽形梁,节点弹性支座模拟支架体系,并通过节点弹性支座的钝化与激活来模拟支架的拆除情况。(4)结合计算结果分析了各种落架顺序的合理性,确定了最优的落架方案并提出了槽形梁落架过程中应该注意的事项。根据计算数据和分析得到了如下结论:(1)全桥各跨按照挠度比例均匀落架对槽形梁的受力最为有利,但当施工环境不允许时,中跨先落架,两边跨随后同时落架的落架方案为最优选择。(2)纵桥向的不均匀落架均不会造成梁的主拉应力超过规范值。但当中跨和某一边跨均已落架,而另一边跨未落架时,在已落架的两跨间中支座处截面上缘会出现较大的拉应力。这种工况在施工中应尽量避免出现。(3)对于梁底较宽的槽形梁来说,横向的不均匀落架会使槽形梁的底板受到较大的拉应力,故横向必须采取同步落架的方式。
[Abstract]:In this paper, the problems of selecting the construction sequence of the falling frame in the construction process of a prestressed concrete continuous girder bridge of a high speed railway are studied. There are some factors in the construction site, such as complex environment, inadequate construction control, improper construction management, and so on. In this paper, by analyzing the force situation of the slot beam under various working conditions which may appear in the asynchronous unloading support, A reasonable scheme of falling frame to meet the limit of construction environment is determined. The main work is as follows: 1) the common construction methods of continuous girder bridge with groove shape are discussed. This paper also discusses in detail the problem of falling frame in the construction of continuous beam bridge with full support method. (2) the problems that may occur in the process of falling frame of slot beam bridge are analyzed. Through the analysis, the force situation of slot beam during asynchronous unloading of longitudinal bridge and transverse bridge is obtained. Midas Civil is used to establish the finite element model for the analysis of the falling frame process. In this paper, according to the different descending order of the forward bridge and the transverse bridge, eight kinds of working conditions are distinguished, and the beam-plate combination element is used to simulate the slot beam. The joint elastic support simulates the support system, and through the passivation and activation of the node elastic support to simulate the removal of the support. The optimal scheme of falling frame is determined and the matters needing attention in the process of falling frame of slot beam are put forward. According to the calculation data and analysis, the following conclusion is drawn: 1) the stress of the slot beam is most favorable when the span of the whole bridge falls evenly according to the deflection ratio. However, when the construction environment does not permit, the first falling frame of the middle span, and the optimal scheme of dropping the frame at the same time between the two spans at the same time, will not cause the main tensile stress of the beam to exceed the standard value. However, the main tensile stress of the beam will not exceed the standard value. However, both the middle span and one side span have already fallen off the frame. However, when the other side of the frame does not fall, the upper edge of the cross section of the middle support between the two spans of the already fallen frame will have a large tensile stress. In this case, we should try to avoid the appearance of .f3 in the construction) for the beam with a wider bottom, The transverse uneven falling frame will make the bottom plate of the slot beam subjected to greater tensile stress, so the horizontal must adopt the mode of synchronous drop frame.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.4

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