自锚式悬索桥主缆线形及吊索张拉方案研究

发布时间：2018-05-04 06:47

本文选题：自锚式悬索桥 + 主缆线形　；参考：《重庆交通大学》2014年硕士论文

【摘要】：自锚式悬索桥是在地锚式悬索桥的基础上发展而来的，它省去了地锚式悬索桥巨大的锚锭，直接将主缆锚固在加劲梁上，考虑到结构受力以及施工等的因素，自锚式悬索桥的跨径一般不大，但是由于其桥型布置的灵活性以及独特的外形，近些年成为了城市桥梁中一种具有较强竞争力的桥型。虽然自锚式悬索桥的研究早在19世纪就已经开始，但是我国直到21世纪才开始修建，且大多数为三跨自锚式悬索桥，独塔自锚式悬索桥的建造则相对较少。本文结合北京潮白河非对称独塔自锚式悬索桥，对自锚式悬索桥的主缆线形以及吊索张拉进行了如下几个方面的探讨和分析： ①对自锚式悬索桥主缆线形的求解方法进行归纳总结，推导了抛物线和悬链线主缆的线形求解公式，同时结合笛卡尔坐标系，推导了基于拉格朗日坐标系求解自锚式悬索桥主缆线形的公式，并根据推导的公式编写了能够求解自锚式悬索桥成桥线形以及施工过程中主缆线形的图形交互程序。 ②由一个两端等高的简支（固结）索，，通过对比分析均布荷载作用下考虑抗弯刚度索的线形解析式与柔性索的线形解析式两者之间的差异得出，考虑抗弯刚度索的线形解析表达式比柔性索多出了一个与线形影响系数（）有关的多项式。通过分析线形影响系数分别趋于0以及无穷得出，当趋于无穷时，具有刚度的索退化为柔性索，当趋于0时，主缆表现为梁的变形特性。 ③以北京潮白河非对称独塔自锚式悬索桥为例，分别用梁单元（考虑主缆抗弯刚度）、索单元（不计主缆抗弯刚度）来模拟自锚式悬索桥的主缆，通过有限元模型计算发现，随着吊索张拉的进行，两个主缆之间的竖向位移差在减小，（由2的分析知主缆水平分力的增加使得主缆抗弯刚度特性退化）且索梁的位移差异主要表现在未张拉吊索处，成桥后位移差异可以忽略。 ④首先通过对独塔自锚式悬索桥三种吊索张拉方案的分析对比得出，独塔自锚式悬索桥适合对称张拉，且以无应力索长和张拉力共同控制吊索张拉能确保安全并提高效率，然后探讨了一种以无应力索长作为控制因素一次张拉吊索的方法，该方法可行但会略微牺牲吊索安全系数，最后讨论了基于影响矩阵调整成桥索力的方法。
[Abstract]:The self anchored suspension bridge is developed on the basis of the ground anchored suspension bridge. It saves the huge anchor ingot of the anchorage suspension bridge, anchors the main cable directly on the stiffening beam. Considering the factors such as structural force and construction, the span of the self anchored suspension bridge is not very large, but because of the flexibility and unique shape of the bridge layout In recent years, it has become a strong competitive bridge type in urban bridges.
Although the study of the self anchored suspension bridge has begun in nineteenth Century, it has not been built until twenty-first Century, and most of them are three span self anchored suspension bridges, and the single tower self anchored suspension bridge is relatively small. This paper combines the unsymmetrical single tower self anchored suspension bridge of the Beijing Chao Bai River to the line shape of the main cable of the self anchored suspension bridge and the main cable shape of the self anchored suspension bridge. The sling tension is discussed and analyzed in the following aspects.
Firstly, the method of solving the line shape of the main cable of the self anchored suspension bridge is summarized, and the linear formula of the main cable of the parabola and catenary is derived. At the same time, combining the Descartes coordinate system, the formula for solving the line shape of the main cable of the self anchored suspension bridge is derived based on the Lagrange coordinate system, and the derivation of the derived formula can be used to solve the self anchored suspension. The Graphic Interaction Program of the cable bridge alignment and the main cable alignment during the construction process.
By comparing and analyzing the difference between the linear analytic formula of the flexural stiffness cable and the linear analytic formula of the flexible cable, the linear analytic expression of the flexural rigidity cable is obtained by comparing and analyzing the difference between the linear analytic formula of the flexural rigidity cable and the linear analytic formula of the flexible cable. The influence coefficient of the over analysis line shape tends to 0 and infinite, and when it tends to infinity, the cable with stiffness degenerates into flexible cable. When it tends to 0, the main cable is shown to be the deformation characteristic of the beam.
(3) taking the unsymmetrical single tower self anchored suspension bridge of the Beijing Chao Bai River as an example, the main cable of the self anchored suspension bridge is simulated with the beam element (considering the flexural rigidity of the main cable) and the cable unit (not counting the bending stiffness of the main cable). Through the finite element model calculation, it is found that the vertical displacement difference between the two main cables decreases with the lifting of the sling, (2 points). It is known that the increase of the horizontal force of the main cable makes the bending stiffness characteristic of the main cable degenerate and the difference of the displacement of the cable beam is mainly shown at the unstretched sling, and the difference of the displacement after the bridge can be ignored.
Firstly, through the analysis and comparison of the three suspending cable tensioning schemes for the single tower self anchored suspension bridge, the single tower self anchored suspension bridge is suitable for symmetric tension, and the safety and efficiency can be ensured by the joint control of the sling without stress cable length and tension force. Then a kind of one tension sling with no stress cable length as a control factor is discussed. The method is feasible, but slightly sacrifices the safety factor of the sling. Finally, the method of adjusting the cable force based on the influence matrix is discussed.

【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.25

【参考文献】