三塔悬索桥主缆与鞍座抗滑移设计研究

发布时间：2018-07-07 23:31

本文选题：三塔悬索桥 + 抗滑移　；参考：《西南交通大学》2015年硕士论文

【摘要】：由于存在着“中塔效应”,三塔悬索桥的行车舒适性要求(挠跨比)与主缆抗滑移安全要求成为一对矛盾体,这使得在三塔悬索桥中主缆与中主鞍座的抗滑移设计成为主要设计内容之一。影响主缆抗滑移安全的因素主要有结构的总体布置、中塔刚度、主缆与鞍座的名义摩擦系数、恒载和活载大小、加劲梁的约束体系等。这些因素对主缆与鞍座的抗滑移安全性能的影响规律需要进行深入的研究和分析。论文简要介绍了三塔悬索桥的主要力学特性和主缆与鞍座抗滑移安全问题的研究进展。忽略加劲梁刚度的影响利用叠加原理计算出主缆抗滑移安全最不利加载模式下的主缆张力水平分量、主缆线形和主缆张力,进而得到三塔悬索桥主缆抗滑移安全系数的估算公式,与有限元法对比表明本文所得公式精度较高。利用此估算公式分析主跨跨度、矢跨比、中塔刚度、恒载和活载对主缆抗滑移安全系数的影响规律。论文采用有限元方法对主缆索股与鞍座的摩擦行为进行分析。利用ANSYS大型通用有限元软件建立单根索股与鞍槽的接触模型。对主缆与鞍座摩擦模型试验中单根索股工况进行仿真模拟,得到单根索股在鞍槽内滑动过程中的索力、位移曲线。并根据有限元结果计算单根索股与鞍槽的名义摩擦系数。论文以一座主跨800m的三塔悬索桥方案为例,对柔性中塔和刚性中塔方案下的加劲梁约束体系进行研究。对比各约束体系下主缆抗滑移安全系数以及恒载、温度荷载、活载作用下约束反力、中塔和主梁应力、加劲梁的位移等结果,分析各种约束体系的优势和不足。同时以此分析结果为基础,对三塔悬索桥采用斜吊索体系和斜-竖组合体系进行研究。分析了斜吊索体系和斜-竖组合体系下加劲梁约束方式对主缆抗滑移安全的影响。
[Abstract]:Because of the "mid-tower effect", the requirements of driving comfort (ratio of deflection to span) of three-tower suspension bridge and the safety requirement of anti-slip of main cable become a pair of contradictions. Therefore, the anti-slip design of the main cable and the main saddle in the three-tower suspension bridge becomes one of the main design contents. The main factors affecting the safety of the main cable are the general arrangement of the structure, the stiffness of the middle tower, the nominal friction coefficient between the main cable and the saddle, the size of dead load and live load, the restraint system of stiffened beam, etc. The influence of these factors on the anti-slip safety performance of the main cable and saddle need to be deeply studied and analyzed. This paper briefly introduces the main mechanical characteristics of the three-tower suspension bridge and the research progress of the anti-slip safety of the main cable and saddle. Ignoring the influence of stiffening beam stiffness, the horizontal component of the main cable tension, the main cable shape and the main cable tension under the most unfavorable loading mode of the main cable anti-slip safety are calculated by using the superposition principle. Furthermore, the formula of the safety coefficient of anti-slip of the main cable of three-tower suspension bridge is obtained. The comparison with the finite element method shows that the formula obtained in this paper has a high accuracy. By using this formula, the effects of span, rise-span ratio, mid-tower stiffness, dead load and live load on the safety factor of the main cable are analyzed. The friction behavior of main cable strands and saddle is analyzed by finite element method. The contact model between single root strands and saddle grooves was established by ANSYS software. In the friction model test of the main cable and saddle, the cable force and displacement curve of the single cable strut in the sliding process of the saddle slot were obtained by simulating the working conditions of the single cable strut in the friction model test of the main cable and saddle. The nominal friction coefficient between single root strands and saddle grooves is calculated according to the finite element results. In this paper, a three-tower suspension bridge with a main span of 800m is taken as an example to study the stiffened beam restraint system under the flexible and rigid mid-tower schemes. Compared with the results of safety factor of anti-slip of main cable and dead load, temperature load, restrained reaction force under live load, stress of middle tower and main beam and displacement of stiffened beam, the advantages and disadvantages of various restraint systems were analyzed. At the same time, based on the analysis results, the slanting sling system and the slanting-vertical composite system are studied for the three-tower suspension bridge. The influence of stiffening beam restraint mode on the slippage safety of the main cable is analyzed in the slanting slings system and the skew-vertical composite system.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.25

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