斜塔自锚式悬索桥静力分析及索塔稳定性研究

发布时间：2019-06-13 22:06

【摘要】：斜塔自锚式悬索桥是一种新式的桥梁结构样式,由于其造型美观、对地形的要求比较低并且适应性较强,因此获得人们的青睐。对于这样比较新颖的结构来说,其受力性能与一般的悬索桥是有所不同的,有必要根据其自身的受力特点进行分析研究。本文以朝阳市燕阳山南路大桥为背景,做了一些静力分析、索塔的稳定性研究和索塔的优化设计的相关工作,可以为类似的桥梁设计和研究提供借鉴。主要工作如下： (1)首先回顾了悬索桥及自锚式悬索桥的发展现状,然后介绍了自锚式悬索桥的计算分析方法、引起几何非线性的要素和非线性问题的几种解法。 (2)利用MIDAS CIVIL建立全桥空间模型,利用节线法和悬链线法确定出该斜塔自锚式悬索桥的成桥线型,考虑了索夹对主缆及吊杆的无应力长度的影响,确定了修正后的主缆及吊杆的无应力长度。对不同的荷载作用,结构主要部分的受力情况进行了分析对比,以确定不同荷载对结构的影响。计算结果表明,除恒载之外,对于主要受力构件来说,活载产生的轴力和位移值最大,其余荷载影响相对较小。 (3)介绍了稳定问题的理论和分析方法,建立ANSYS模型对斜塔自锚式悬索桥的索塔进行了稳定性分析。通过建立不同的单元模型,得到了弹性稳定、几何非线性和材料非线性稳定在不同工况下的稳定系数,并对结果进行了对比分析。结果表明双重非线性的稳定系数较几何非线性相比相差较大,仅为几何非线性的42%左右。因此,在计算类似结构的稳定性时,应该考虑几何非线性和材料非线性的影响。 (4)对钢管桁架的结构形式和设计做了简要的介绍,指出桁架设计的关键问题。主要对影响钢管桁架索塔稳定性的因素进行分析,对比了不同主管壁厚、不同主管直径、不同斜撑布置方式和不同宽高比对索塔稳定性的影响,为钢管桁架的索塔设计提供参考。结果表明,主管壁厚选择45mm,主管直径选择1.6m能够满足稳定性的要求,并且材料的应力储备也较好。达到同样的稳定效果之下,Warren型布置方式比Pratt型布置方式节省材料约16.9%左右。随着宽高比的增加,索塔的稳定性先增大后降低。当宽高比为0.7时,结构的稳定系数最高。
[Abstract]:Inclined tower self-anchored suspension bridge is a new type of bridge structure. Because of its beautiful shape, low requirements for terrain and strong adaptability, it has been favored by people. For such a relatively novel structure, its mechanical performance is different from that of the general suspension bridge, so it is necessary to analyze and study it according to its own stress characteristics. Based on the background of Yanyang Mountain South Road Bridge in Chaoyang City, this paper makes some static analysis, the research on the stability of the cable tower and the optimization design of the cable tower, which can be used for reference for similar bridge design and research. The main work is as follows: (1) the development status of suspension bridge and self-anchored suspension bridge is reviewed, and then the calculation and analysis method of self-anchored suspension bridge, the elements causing geometric nonlinear and several solutions of nonlinear problems are introduced. (2) the spatial model of the whole bridge is established by MIDAS CIVIL, and the bridge line of the inclined tower self-anchored suspension bridge is determined by using the section method and catenary method. The influence of cable clip on the stress-free length of the main cable and suspender is considered, and the stress-free length of the modified main cable and suspender is determined. The effects of different loads on the main parts of the structure are analyzed and compared in order to determine the influence of different loads on the structure. The calculation results show that, except for dead load, the axial force and displacement produced by live load are the largest, and the influence of other loads is relatively small. (3) the theory and analysis method of the stability problem are introduced, and the ANSYS model is established to analyze the stability of the cable tower of the inclined tower self-anchored suspension bridge. By establishing different element models, the stability coefficients of elastic stability, geometric nonlinear and material nonlinear stability under different working conditions are obtained, and the results are compared and analyzed. The results show that the stability coefficient of the double nonlinear is only about 42% of the geometric nonlinear compared with the geometric nonlinear. Therefore, the effects of geometric nonlinear and material nonlinear should be considered when calculating the stability of similar structures. (4) the structural form and design of steel pipe truss are briefly introduced, and the key problems of truss design are pointed out. The factors affecting the stability of steel pipe truss cable tower are analyzed, and the effects of different main wall thickness, different main pipe diameter, different oblique brace arrangement and different width and height on the stability of steel pipe truss cable tower are compared, which provides a reference for the cable tower design of steel pipe truss. The results show that the wall thickness of the supervisor is 45 mm and the diameter of the supervisor is 1.6 m, which can meet the requirements of stability, and the stress reserve of the material is also good. Under the same stable effect, the Warren arrangement saves about 16.9% of the material compared with the Pratt arrangement. With the increase of aspect ratio, the stability of cable tower increases at first and then decreases. When the aspect ratio is 0.7, the stability coefficient of the structure is the highest.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.25

【参考文献】