大跨度公铁两用斜拉桥稳定性分析

发布时间：2018-03-31 03:32

本文选题：大跨度公铁两用斜拉桥　切入点：稳定性理论　出处：《北京交通大学》2015年硕士论文

【摘要】：本文以某大跨度公铁两用斜拉桥为工程背景,通过理论分析和有限元数值模拟计算两种方法对其稳定性进行研究,分别得到大跨度公铁两用斜拉桥施工阶段和成桥状态下的稳定性分布规律,为今后大跨度公铁两用斜拉桥的设计分析提供技术参考。本文主要完成了以下研究工作： (1)详细阐述了公铁两用斜拉桥的发展状况和结构特点,结构稳定性分析理论、分析方法和斜拉桥稳定分析的有限元理论,并对斜拉桥稳定安全系数标准进行了探讨分析。 (2)采用大型有限元软件Midas Civil建立大跨度公铁两用斜拉桥有限元模型,并对其施工阶段和成桥状态分别进行稳定性分析。根据计算分析结果,获得了大跨度公铁两用斜拉桥的屈曲模态和稳定安全系数的变化趋势,结果表明,大跨度公铁两用斜拉桥在成桥阶段易发生整体稳定性问题,而在施工阶段更易发生局部稳定性问题。 (3)根据《钢结构设计规范》(GB50017-2003)和《铁路桥梁钢结构设计规范》(TB10002.2-2005)中压弯杆件的计算公式,对最大双悬臂、最大单悬臂和成桥阶段三个典型施工阶段最不利杆件进行了杆件稳定性计算分析。分析结果表明,采用理论公式计算方法得到的数值结果与采用有限元方法得到的第二类稳定性计算分析结果吻合较好。 (4)对大跨度公铁两用斜拉桥施工阶段有限元模型进行稳定性分析,根据所建立的有限元模型,分别考虑主桁类型、主桁高度、主塔刚度及斜拉索面积的变化对施工阶段稳定性的影响。并考虑施工方法的改变对施工阶段稳定性的影响,施工方法的改变对施工阶段的稳定性具有显著影响。 (5)根据所建立的有限元模型,考虑最大双悬臂、最大单悬臂和成桥阶段三个典型施工阶段不同位置斜拉索断裂的影响,并进行计算分析。根据计算分析结果可知斜拉索断裂对稳定性具有一定影响,应引起设计、施工和养护维修的注意,确保结构安全。综上所述,本文通过对大跨度公铁两用斜拉桥的有限元模型进行计算分析,得到其施工阶段第一类和第二类稳定性规律,并考虑设计参数的改变对施工阶段及成桥状态稳定性的影响,为同类斜拉桥设计提供一定的技术参考。
[Abstract]:In this paper, based on the engineering background of a large-span cable-stayed bridge, the stability of the bridge is studied by means of theoretical analysis and finite element numerical simulation. The stability distribution of the long-span highway / iron cable-stayed bridge under the construction stage and the completed state is obtained respectively, which provides a technical reference for the design and analysis of the large-span cable-stayed bridge. The main work of this paper is as follows:. 1) the development and structural characteristics, structural stability analysis theory, analysis method and finite element theory of cable-stayed bridge stability are described in detail, and the criterion of stability safety factor of cable-stayed bridge is discussed. The finite element model of the large-span cable-stayed bridge is established by Midas Civil, and the stability of the bridge is analyzed in the construction stage and the state of the bridge. The variation trend of buckling mode and stability safety factor of large-span cable-stayed bridge is obtained. The results show that the overall stability of long-span cable-stayed bridge is easy to occur in the stage of completion. However, local stability is more likely to occur in the construction stage. The maximum double cantilever is obtained according to the calculation formulas of bending members in the Code for Design of Steel structures (GB50017-2003) and the Code for Design of Steel structures of Railway Bridges (TB10002.2-2005). The stability of the most unfavorable members in the three typical construction stages of the maximum single cantilever and the bridge is calculated and analyzed. The results show that, The numerical results obtained by the theoretical formula method are in good agreement with the results of the second kind of stability analysis obtained by the finite element method. 4) the stability analysis of the finite element model of large-span double-purpose cable-stayed bridge in construction stage is carried out. According to the established finite element model, the type of main truss and the height of main truss are considered respectively. The influence of the change of the stiffness of the main tower and the area of stay cable on the stability of the construction stage and the influence of the change of the construction method on the stability of the construction phase are considered. The change of the construction method has a significant effect on the stability of the construction phase. 5) according to the established finite element model, considering the influence of the maximum double cantilever, the maximum single cantilever and the bridge stage in the three typical construction stages, the cable fracture at different positions. According to the results of calculation and analysis, it can be seen that the cable fracture has certain influence on the stability, which should arouse the attention of design, construction and maintenance to ensure the safety of the structure. To sum up, through the calculation and analysis of the finite element model of the large-span cable-stayed bridge, the stability of the first type and the second type in the construction stage is obtained. The influence of the design parameters on the stability of the construction stage and the state of the completed bridge is considered, which provides a certain technical reference for the design of the similar cable-stayed bridges.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.27

【参考文献】