曲率半径变化对连续刚构桥受力性能影响规律的研究

发布时间：2018-10-12 21:32

【摘要】：随着高等级公路普遍建造,曲线连续刚构桥由于能够很好符合山区的优势将会被大量修建,但此类桥梁结构受力比较复杂,如何准确地计算其内力和变形就成为一个很重要的问题。因此,对曲线连续刚构桥的结构计算进行研究是很有必要的。目前国内的桥梁专用计算软件,主要是平面分析程序,不能满足曲线连续刚构桥这种空间结构的要求。韩国的MIDAS软件能够对曲线连续刚构桥进行空间计算分析,本文即使用MIDAS对一座曲线连续刚构实桥进行了计算分析,并在此基础上改变主梁平面曲率,应用MIDAS开展曲线连续刚构桥各主要施工阶段不同平曲线半径的内力和变形计算,并对计算结果进行总结分析,从而研究分析曲率变化对主梁内力和变形的影响。为此,本论文开展了以下工作:1.根据实际施工情况,应用MIDAS计算实桥在自重、预应力、施工荷载等作用下主梁各主要施工阶段的内力(弯矩、扭矩等)和变形(扭转、径向位移等)。2.在不改变墩高、主梁跨径、预应力钢筋等的前提下,通过改变主梁的平曲线半径,对比分析实桥在最大悬臂状态结构、成桥阶段、活载作用阶段的结构内力及变形。计算结果表明:从平曲线半径584m到高速公路平曲线一般最小半径200m变化时,主梁弯矩随着曲率半径的减小而减小,最大增量为活载作用下最大弯矩值,其增量为7%不到,可以忽略,主梁竖向挠度在各跨跨中最大,随着曲率半径的减小而增大,总体上增加的幅度较小,可以忽略。主梁扭矩和径向位移在墩顶处最大,随着曲率半径的减小而快速增加,总体上变化较大,在设计计算和施工过程中不能忽略。主梁的扭转角在最大悬阶段时,1/4跨附近最大,成桥阶段时跨中最大,但都随着曲率半径的减小而快速增加,总体变化较大,应引起足够的重视,需考虑是否设置扭转预拱度问题,而在活载作用下扭转角反而减小,可以不用考虑曲率影响。本文为曲线连续刚构桥的设计、计算和施工提供了一定的参考,也为后期进行曲线连续刚构桥梁不同跨径以及墩高的对比分析积累经验。
[Abstract]:With the general construction of high-grade highways, curved continuous rigid frame bridges will be built in large quantities because they can well conform to the advantages of mountain areas, but the structures of this kind of bridges are more complicated. How to calculate the internal force and deformation accurately becomes a very important problem. Therefore, it is necessary to study the structure calculation of curved continuous rigid frame bridge. At present, the domestic special calculation software for bridges is mainly a plane analysis program, which can not meet the requirements of curved continuous rigid frame bridges. The MIDAS software of Korea can calculate and analyze the curved continuous rigid frame bridge in space. In this paper, a curved continuous rigid frame bridge is calculated and analyzed by MIDAS, and the plane curvature of the main beam is changed. The internal force and deformation of curved continuous rigid frame bridge are calculated with MIDAS, and the calculation results are summarized and analyzed to study the influence of curvature change on the internal force and deformation of main beam. Therefore, this paper has carried out the following work: 1. According to the actual construction conditions, the internal forces (moment, torque, etc.) and deformation (torsion, radial displacement, etc.) of the main girder in each construction stage under the action of weight, prestress and construction load are calculated by using MIDAS. 2. On the premise of not changing the pier height, the span of the main beam and the prestressed steel bar, the internal force and deformation of the real bridge in the maximum cantilever state structure, the bridge completion stage and the live load action stage are analyzed by changing the plane curve radius of the main beam. The calculation results show that the bending moment of the main beam decreases with the decrease of the radius of curvature, and the maximum increment is the maximum moment value under the action of live load, and the increment is less than 7%, when the radius of the plane curve changes from 584m to 200m. It can be neglected that the vertical deflection of the main beam is the largest in each span and increases with the decrease of the radius of curvature. The torsion moment and radial displacement of the main beam are maximum at the top of the pier and increase rapidly with the decrease of the radius of curvature, which can not be ignored in the course of design, calculation and construction. When the torsion angle of the main beam is in the maximum suspension stage, the maximum is near the 1 / 4 span, and the middle span is the largest in the bridge stage, but it increases rapidly with the decrease of the curvature radius, and the overall change is large, so it should be paid enough attention to. It is necessary to consider whether to set the torsional precamber, but the torsion angle decreases under the action of live load, so the curvature effect can be ignored. This paper provides a certain reference for the design, calculation and construction of curved continuous rigid frame bridge, and accumulates experience for the comparative analysis of different span and pier height of curved continuous rigid frame bridge in the later stage.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.23

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