千米级公铁两用斜拉桥设计参数及索塔锚固区受力性能研究

发布时间：2018-07-27 17:28

【摘要】：大跨度公铁两用斜拉桥,由于其结构刚度大、抗风性能好、造价相对较低的优点,使其成为公铁两用大桥设计时的首选桥型。近年来,公铁两用斜拉桥跨度不断增大,乃至突破千米级,而目前对其主要设计参数和索塔锚固区还缺乏系统的研究。本文针对公铁两用斜拉桥的活载加载标准、主要设计参数和索塔锚固区局部受力性能进行研究,主要完成了以下研究工作:(1)概述了国内外公铁两用斜拉桥的发展现状与结构特点,论述了斜拉桥结构分析理论:有限元理论、几何非线性理论、局部分析理论,对相关理论进行了介绍和必要的梳理。(2)本文以某千米级公铁两用斜拉桥为工程背景,采用通用有限元软件建立斜拉桥的空间有限元计算模型。分析了合理成桥状态下的拉索索力分布、主桁上、下弦杆竖向位移和应力,同时计算了斜拉桥的前二十阶振型。研究了千米级公铁两用斜拉桥的活载加载标准,分析了不同活载加载长度对斜拉桥的主桁上、下弦杆竖向位移和内力、桥塔位移和内力及拉索索力的影响。(3)考虑桥梁主要设计参数:边跨辅助墩布置形式、边中跨比、塔梁高跨比、主梁高跨比和主梁宽跨比,研究上述设计参数在一定范围内变化时结构的静力特性和自振特性,对比分析主要设计参数对斜拉桥静力特性、自振特性的敏感性,总结归纳出设计参数对千米级公铁两用斜拉桥的影响规律。(4)选取承受拉索水平分力最大的索塔锚固区节段模型,研究了在1.1倍恒载设计索力作用下,钢锚梁及钢牛腿的变形及受力状态,并详细分析了钢锚梁各个板件的应力状态;分析了钢锚梁腹板加劲板在索力传递时的作用,并研究了不同加劲板数量、厚度、宽度下钢锚梁顶板、底板及腹板连接位置的受力状态。综上所述,通过对千米级公铁两用斜拉桥活载加载标准、主要设计参数、索塔锚固区应力和变形的研究,得到了有益的结论。研究的成果可供同类型桥梁设计参考。
[Abstract]:Due to its advantages of high stiffness, good wind resistance and relatively low cost, the large-span cable-stayed bridge is the first choice in the design of the bridge. In recent years, the span of double-purpose cable-stayed bridge is increasing, even breaking through the kilometer level, but the main design parameters and cable tower anchoring area are still lack of systematic research. In this paper, the main design parameters and the local mechanical behavior of cable tower anchoring zone are studied according to the standard of live load, the main design parameters and the local mechanical behavior of cable-stayed bridge. The main works are as follows: (1) the development status and structural characteristics of the cable-stayed bridges at home and abroad are summarized, and the structural analysis theories of cable-stayed bridges are discussed: finite element theory, geometric nonlinear theory, local analysis theory, and so on. The related theories are introduced and combed. (2) based on the engineering background of a kilometer class double-purpose cable-stayed bridge the spatial finite element model of cable-stayed bridge is established by using the general finite element software. In this paper, the distribution of cable force, the vertical displacement and stress of chord on main truss are analyzed, and the first twenty vibration modes of cable-stayed bridge are calculated. In this paper, the working load standard of the cable-stayed bridge is studied, and the vertical displacement and internal force of the chord on the main truss of the cable-stayed bridge with different live load length are analyzed. (3) considering the main design parameters of the bridge: the arrangement of side span auxiliary pier, the ratio of side to middle span, the ratio of tower beam height to span, the ratio of main beam height to span and the ratio of main beam width to span. The static and natural vibration characteristics of the structure are studied when the above design parameters change within a certain range. The sensitivity of the main design parameters to the static and natural vibration characteristics of cable-stayed bridges is compared and analyzed. The influence of design parameters on the cable-stayed bridge of kilometer scale is summarized. (4) the model of cable tower Anchorage zone which bears the maximum horizontal splitting force of cable is selected, and the design cable force under 1.1 times dead load is studied. The deformation and stress state of steel anchor beam and steel corbel are analyzed, and the stress state of each plate of steel anchor beam is analyzed in detail, the effect of stiffening plate of steel anchor beam web plate on cable force transfer is analyzed, and the quantity and thickness of different stiffening plate are studied. Stress state of steel anchor beam roof, bottom plate and web connection position under width. To sum up, a useful conclusion is obtained by studying the live load standard, main design parameters, stress and deformation of cable tower Anchorage zone for the cable-stayed bridge of kilometer scale. The results of the study can be used as reference for the design of the same type of 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】：2017
【分类号】：U448.27

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