悬索桥索塔的稳定性全过程分析

发布时间：2018-04-05 16:05

本文选题：索塔　切入点：稳定性　出处：《长安大学》2015年硕士论文

【摘要】：在众桥梁体系中,悬索桥以其跨越能力强、造价较低的特点越来越受到建设者的青睐。作为悬索桥受力体系中的重要承重构件,索塔的受力性能也成为悬索桥设计中至关重要的一环。特别是随着塔身的高耸化、塔柱截面的薄壁化以及各种新材料新工艺的应用,使得索塔的刚度降低,其稳定性问题也愈发值得去探究。本文对索塔进行稳定性分析时,主要进行了以下研究内容:1.首先介绍了悬索桥体系中常见的索塔结构形式和受力特点,并在总结国内外对索塔稳定性问题研究的基础上,从有限元法的角度分析了索塔失稳的原因,并提出了结构稳定性的评价指标。2.结合算例对受压杆件的两类稳定性做了详细的计算,并通过考虑不同非线性因素分析了压杆的稳定性破坏机理。建议对同类构件进行稳定性分析时,不可仅计入任一种单一的非线性因素,应综合考虑双重非线性因素的影响。3.对依托工程中的索塔稳定性进行了详细的分析计算,主要对裸塔和成桥状态两个工况进行。通过对其屈曲稳定性进行计算并得出结论,证明主缆的约束作用对索塔的稳定性影响十分明显,以致可以改变其失稳的方向,并提高了索塔结构的整体稳定性。4.通过计入初始缺陷和双重非线性因素对索塔进行了极限承载力分析,得到索塔的第二类稳定安全系数在第一类稳定安全系数的0.12~0.31倍之间,且失稳时均为索塔底部混凝土材料发生受压破坏。5.对影响索塔稳定性的几种主要因素进行了参数化分析,量化了其影响的程度,本文选取了非线性因素、初始缺陷、约束条件、索塔刚度和静风荷载五种因素。
[Abstract]:In the common bridge system, the suspension bridge is more and more favored by the builders because of its strong span ability and low cost.As an important load-bearing member of suspension bridge, the mechanical behavior of cable tower has become an important part in the design of suspension bridge.Especially with the towering of tower the thin-walled section of tower column and the application of various new materials and new technology make the stiffness of cable tower reduce and its stability problem is more and more worth to explore.In this paper, the stability of the cable tower analysis, mainly carried out the following research content: 1.This paper first introduces the common structural forms and mechanical characteristics of cable towers in suspension bridge system, and on the basis of summing up the research on the stability of cable towers at home and abroad, analyzes the causes of tower instability from the point of view of finite element method.The evaluation index of structural stability.In this paper, two kinds of stability of compression bar are calculated in detail with examples, and the failure mechanism of compression rod is analyzed by considering different nonlinear factors.It is suggested that any single nonlinear factor should not be taken into account in the stability analysis of similar components, and the influence of double nonlinear factors should be considered synthetically.The stability of cable tower in supporting engineering is analyzed and calculated in detail, mainly for bare tower and bridge state.By calculating the buckling stability of the cable, it is proved that the constraint effect of the main cable on the stability of the cable tower is so obvious that the direction of its instability can be changed, and the overall stability of the tower structure can be improved by .4.By taking into account the initial defects and the double nonlinear factors, the ultimate bearing capacity of the cable tower is analyzed, and the stability safety factor of the second kind of cable tower is obtained in the range of 0.12 ~ 0.31 times of that of the first type.The concrete material at the bottom of the cable tower is subjected to compressive failure.The main factors affecting the stability of the cable tower are parameterized and the degree of influence is quantified. Five factors are selected in this paper: nonlinear factor, initial defect, constraint condition, tower stiffness and static wind load.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.25

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