高墩大跨连续刚构弯桥结构稳定性和动力分析
发布时间：2019-04-26 02:00
【摘要】：从近30年来美国1971年的圣费南多地震到2013年中国湖北巴东地震,桥梁结构一直是受到震害最为严重的一类结构。针对这一现象,各国有关专家对桥梁动力问题的研究展开了许多新的研究与讨论。但是绝大部分的研究都是关于静力特性方面的,且研究的目标多以直桥为主,对于动力特性的研究也比较少,研究深度也比较浅。但是在实际施工中,很多桥梁都采用高墩、弯梁,墩高甚至可达百米以上,而高墩又对动力特征具有放大作用且使得曲率半径对动力特性的影响增大,所以对曲线桥其进行动力特性的研究也是很有必要的。此外,在桥梁工程中许多结构都存在稳定问题,其中高墩稳定是需要重点关注的一类,特别是随着科学技术的发展,各类高强度材料在工程中被广泛采用,结构构件的尺寸变得相对较单薄。这让结构的稳定性问题进一步突出,使其成为了结构设计中的控制因素。通过对桥梁结构的动力特性和稳定特性进行计算分析,能够得到各个阶段结构的频率、振型和屈曲特征值,使得我们能够进一步的了解桥梁结构的刚度大小和刚度分布等情况。这为我们判断桥梁结构受力相对脆弱的部位提供了便利条件,也可以达到指导桥梁结构设计方案的优化调整以及为桥梁设计提供技术依据的目的。总结这些问题并展开研究,结合现阶段有关研究现状,本文做的具体工作如下：(1)阐述了高墩大跨连续刚构曲线桥的发展过程,桥梁未来的发展趋势和刚构桥这一桥型的发展趋势。并针对目前桥梁结构的动力、稳定问题分别对大跨度桥梁、高墩和弯桥这三种情况进行详细的分析。介绍了线性跟非线性稳定理论以及分析稳定问题的方法和评价的指标。(2)以一正在施工的连续刚构弯桥西牛大桥作为工程背景,对高墩大跨连续刚构桥弯桥在曲率半径变化时的动力特性进行研究,对不同曲率半径下桥梁结构在最大悬臂阶段和全桥阶段时的自振周期和振型进行分析,总结出在曲率半径变化时桥梁结构动力特性的变化情况。采用反应谱法对不同曲率半径桥梁在地震作用下的动力特性进行分析,采用动力时程法着重对西牛大桥进行地震分析,为西牛大桥的施工设计优化提供了一个理论依据。(3)对西牛大桥在自重、横向风荷载跟纵向风荷载作用下的高墩自体稳定性做出分析；对最大悬臂阶段在五种不利荷载组合下的稳定性进行分析；对运营阶段(全桥阶段)在五种不利荷载组合下进行稳定性分析,对结果进行分析对比得出结论。(4)对高墩大跨连续刚构弯桥的动力特性和稳定性研究进行总结与展望。
[Abstract]:From the San Fernand earthquake in 1971 to the Padong earthquake in Hubei Province in 2013, the bridge structure has been one of the most severely damaged structures. In view of this phenomenon, many new researches and discussions on bridge dynamics have been carried out by experts from all over the world. However, most of the studies are about static characteristics, and most of the research targets are straight bridges, the dynamic characteristics of the research is also relatively few, the depth of research is also relatively shallow. However, in practical construction, many bridges adopt high pier, curved beam, pier height or even more than 100 meters, and high pier has magnifying effect on dynamic characteristics and makes the influence of curvature radius on dynamic characteristics increase. So it is necessary to study the dynamic characteristics of curved bridge. In addition, there are many structural stability problems in bridge engineering, among which the stability of high pier is one of the most important problems, especially with the development of science and technology, all kinds of high strength materials are widely used in the engineering. The dimensions of structural members become relatively thin. This makes the stability of the structure more prominent and becomes the control factor in the structure design. Through the calculation and analysis of the dynamic and stability characteristics of the bridge structure, the frequencies, mode shapes and buckling eigenvalues of each stage of the structure can be obtained, which enables us to further understand the stiffness size and stiffness distribution of the bridge structure. This provides a convenient condition for us to judge the position where the bridge structure is relatively fragile, and it can also guide the optimization and adjustment of the bridge structure design scheme and provide the technical basis for the bridge design. According to the present research situation, the concrete work of this paper is as follows: (1) the development process of continuous rigid frame bridge with high pier and long span is expounded. The development trend of bridge and rigid frame bridge in the future. In view of the dynamic and stability problems of the current bridge structure, the long-span bridge, the high pier and the curved bridge are analyzed in detail. This paper introduces the linear and nonlinear stability theory, the method of analyzing the stability problem and the evaluation index. (2) based on the construction of a continuous rigid frame curved bridge Xiniu Bridge as the engineering background, The dynamic characteristics of curved bridge with high pier and long span continuous rigid frame bridge under the change of curvature radius are studied. The natural vibration period and mode shape of the bridge structure at the maximum cantilever stage and the full bridge stage under different radius of curvature are analyzed. The variation of dynamic characteristics of bridge structure with the change of curvature radius is summarized. The dynamic characteristics of bridges with different radius of curvature under earthquake are analyzed by response spectrum method, and the dynamic time-history method is used to analyze the earthquake of Xiniu Bridge. It provides a theoretical basis for the construction design optimization of Xiniu Bridge. (3) the stability of high pier under the action of self-weight, transverse wind load and longitudinal wind load is analyzed. The stability of the maximum cantilever stage under five unfavourable loads is analyzed. The stability analysis of operation stage (full bridge stage) under five kinds of adverse loads is analyzed and compared. (4) the dynamic characteristics and stability of long-span continuous rigid frame bending bridge with high pier and long span are summarized and prospected.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.23
，
本文编号：2465657
[Abstract]:From the San Fernand earthquake in 1971 to the Padong earthquake in Hubei Province in 2013, the bridge structure has been one of the most severely damaged structures. In view of this phenomenon, many new researches and discussions on bridge dynamics have been carried out by experts from all over the world. However, most of the studies are about static characteristics, and most of the research targets are straight bridges, the dynamic characteristics of the research is also relatively few, the depth of research is also relatively shallow. However, in practical construction, many bridges adopt high pier, curved beam, pier height or even more than 100 meters, and high pier has magnifying effect on dynamic characteristics and makes the influence of curvature radius on dynamic characteristics increase. So it is necessary to study the dynamic characteristics of curved bridge. In addition, there are many structural stability problems in bridge engineering, among which the stability of high pier is one of the most important problems, especially with the development of science and technology, all kinds of high strength materials are widely used in the engineering. The dimensions of structural members become relatively thin. This makes the stability of the structure more prominent and becomes the control factor in the structure design. Through the calculation and analysis of the dynamic and stability characteristics of the bridge structure, the frequencies, mode shapes and buckling eigenvalues of each stage of the structure can be obtained, which enables us to further understand the stiffness size and stiffness distribution of the bridge structure. This provides a convenient condition for us to judge the position where the bridge structure is relatively fragile, and it can also guide the optimization and adjustment of the bridge structure design scheme and provide the technical basis for the bridge design. According to the present research situation, the concrete work of this paper is as follows: (1) the development process of continuous rigid frame bridge with high pier and long span is expounded. The development trend of bridge and rigid frame bridge in the future. In view of the dynamic and stability problems of the current bridge structure, the long-span bridge, the high pier and the curved bridge are analyzed in detail. This paper introduces the linear and nonlinear stability theory, the method of analyzing the stability problem and the evaluation index. (2) based on the construction of a continuous rigid frame curved bridge Xiniu Bridge as the engineering background, The dynamic characteristics of curved bridge with high pier and long span continuous rigid frame bridge under the change of curvature radius are studied. The natural vibration period and mode shape of the bridge structure at the maximum cantilever stage and the full bridge stage under different radius of curvature are analyzed. The variation of dynamic characteristics of bridge structure with the change of curvature radius is summarized. The dynamic characteristics of bridges with different radius of curvature under earthquake are analyzed by response spectrum method, and the dynamic time-history method is used to analyze the earthquake of Xiniu Bridge. It provides a theoretical basis for the construction design optimization of Xiniu Bridge. (3) the stability of high pier under the action of self-weight, transverse wind load and longitudinal wind load is analyzed. The stability of the maximum cantilever stage under five unfavourable loads is analyzed. The stability analysis of operation stage (full bridge stage) under five kinds of adverse loads is analyzed and compared. (4) the dynamic characteristics and stability of long-span continuous rigid frame bending bridge with high pier and long span are summarized and prospected.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.23
，
本文编号：2465657
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