斜拉—悬吊协作体系桥梁设计关键问题研究

发布时间：2018-03-21 20:34

本文选题：斜拉-悬吊协作体系桥梁　切入点：有限元分析　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：国内外跨海连岛工程建设对桥梁的跨径提出了更高的要求。在新材料和施工工法等技术发展的同时,设计具备更大跨越能力的桥梁结构体系显得尤为重要。斜拉-悬吊协作体系桥梁是在斜拉桥和悬索桥的基础上发展而来的一种新型缆索承重桥梁。它把这两种桥型结合起来,如能扬长避短,则在大跨度桥梁结构上有很大的竞争力。但由于这种结构形式尚存在一些亟待解决的关键技术问题,目前国内外尚无真正意义上的斜拉-悬吊协作体系桥梁实践。本文以洞庭湖二桥斜拉-悬吊协作体系桥梁方案为工程背景,运用桥梁结构静动力非线性分析系统BNLAS建立了全桥有限元模型,对设计中存在的一些关键问题进行了研究,具体工作和相关结论如下:(1)分析了斜拉-悬吊协作体系桥梁在纵桥向、竖向和扭转向刚度,讨论了增大结构刚度的体系影响因素;对主要受力构件的活载影响线进行了分析,研究了吊索与斜拉索的相互影响;讨论了温度作用下吊索、主缆、主塔和加劲梁的受力特征。对该体系的若干关键参数进行了比较分析,确定了合理的结构布置形式。(2)确定了斜拉-悬吊协作体系桥梁合理成桥状态的设计准则和实现步骤。经过多次优化调整,得到了合理的加劲梁线形、斜拉索张拉力、吊索无应力长度和主缆几何线形,从而确定了较合理的斜拉-悬吊协作体系桥梁成桥内力状态。(3)对斜拉-悬吊协作体系桥梁的施工过程进行了仿真分析,讨论了斜拉-悬吊协作体系桥梁方案的施工可实施性;对洞庭湖二桥的斜拉-悬吊协作体系桥梁方案进行了结构整体计算分析,验算了主要构件的受力、位移等。(4)针对疲劳问题较突出的中跨过渡区斜拉索、吊索和加劲梁,采用不同的疲劳荷载进行了验算,并讨论了大跨度桥梁整体疲劳验算荷载选择的方法和可行性。研究表明,斜拉-悬吊协作体系桥梁的纵向、横向及竖向刚度均大于常规单跨悬索桥;获得了影响斜拉-悬吊协作体系桥梁结构性能的关键参数;确定了结构合理的成桥状态。计算表明施工方法安全可靠、方便可行;主要构件的疲劳应力幅小于控制疲劳应力幅,结构整体疲劳性能满足规范要求。本文所开展的工作和得到的结论,对此种桥梁结构的认识和推广将起到了重要的作用。
[Abstract]:At home and abroad, the construction of offshore and island crossing projects has put forward higher requirements for the span of bridges. At the same time of the development of new materials and construction methods and other technologies, It is particularly important to design a bridge structure with greater span capacity. The cable-stayed suspension system bridge is a new type of cable-bearing bridge developed on the basis of cable-stayed bridge and suspension bridge. It combines the two types of bridge. If we can take advantage of the advantages and avoid the disadvantages, we will have great competitiveness in the long-span bridge structure. However, there are still some key technical problems to be solved in this structure form. At present, there is no real practice of cable-stayed suspension system bridge at home and abroad. This paper takes the bridge scheme of the second bridge of Dongting Lake as the engineering background. The finite element model of the whole bridge is established by using the bridge structure static and dynamic nonlinear analysis system (BNLAS), and some key problems in the design are studied. The concrete work and related conclusions are as follows: 1) analyzing the longitudinal, vertical and torsional stiffness of cable-stayed suspension system bridges, discussing the influence factors of increasing the structural stiffness, and analyzing the live load influence lines of the main load-bearing members. The interaction between sling and stay cable is studied, the stress characteristics of sling, main cable, main tower and stiffened beam under the action of temperature are discussed, and some key parameters of the system are compared and analyzed. The design criteria and realization steps for the reasonable state of bridge completion of cable-stayed suspension cooperative system bridges are determined. After several optimization adjustments, the reasonable stiffening beam line shape and cable tension are obtained. The length of the sling without stress and the geometry of the main cable are determined, so that the reasonable internal force state of the cable-stayed suspension system bridge is determined. 3) the construction process of the cable-stayed suspension cooperative system bridge is simulated and analyzed. The construction feasibility of the cable-stayed suspension system bridge scheme is discussed, and the structural integral calculation and analysis of the cable-stayed suspension cooperative system bridge scheme of Dongting Lake second Bridge are carried out, and the stress of the main components is checked and calculated. Displacement, etc. (4) checking calculation of cable, slings and stiffened beams in mid-span transition zone with different fatigue loads is carried out, and the method and feasibility of load selection for overall fatigue checking of long-span bridges are discussed. The longitudinal, transverse and vertical stiffness of the cable-stayed suspension system bridge is higher than that of the conventional single-span suspension bridge, and the key parameters affecting the structural performance of the cable-stayed suspension system bridge are obtained. The calculation shows that the construction method is safe, reliable, convenient and feasible, and the fatigue stress amplitude of the main components is smaller than that of the control fatigue stress amplitude. The fatigue property of the structure as a whole can meet the requirements of the code. The work carried out in this paper and the conclusions obtained will play an important role in understanding and popularizing this kind of bridge structure.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.5

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