自锚式悬索—斜拉组合体系桥合理成桥状态及参数分析

发布时间：2018-06-04 03:30

本文选题：缆索承重体系 + 组合体系　；参考：《长安大学》2015年硕士论文

【摘要】：近年来由于交通事业蓬勃发展,对桥梁结构体系创新的要求愈来愈高,桥梁工作者也愈发重视桥梁结构的新颖和力学美。结构体系创新取得的最瞩目的成就之一就是缆索承重体系的演变,斜拉桥和悬索桥外形美观,富有震撼力,能起到标志性建筑的作用。斜拉桥刚强有力,悬索桥妩媚纤巧,把两者结合起来的组合体系则体现了刚与柔的结合美。组合体系与自锚式悬索桥相比,抗风稳定性较好,与斜拉桥相比,主塔高度有所减小,同时省掉巨大的锚碇,因此组合体系适用于较差的地质条件,且可以提高经济性能,有很大的竞争力。本文以汉中市龙岗大桥为背景工程,对自锚式悬索—斜拉组合体系桥进行了如下研究:(1)本文对自锚式悬索—斜拉组合体系的合理成桥状态进行研究,在目前的悬索桥和斜拉桥合理成桥状态方法的基础上,引入了分步成桥状态计算方法,即把模型分解成自锚式悬索段和斜拉段:利用节线法得到主缆的初始线形,既而利用索单元模拟主缆,考虑非线性开始迭代分析,得到自锚式悬索段合理成桥状态;利用弯曲能量最小法初步得到斜拉索力,运用影响矩阵法初步进行斜拉索力的优化,运用索单元模拟拉索,进行非线性迭代确定斜拉段的合理成桥状态;最后用合龙段把两部分连接成整体后,原来两部分各自的平衡状态被打破,结构发生新的变形,悬索部分背索和斜拉部分拉索的索力发生变化,应用不变形预张力的索力不变原理修正背索和拉索索力即首先计算出合龙后所有背索和斜拉索的索长,然后把合龙前后背索和斜拉索的索长变化量计入无应力索长,再运行分析得到组合体系的合理成桥状态。(2)自锚式悬索—斜拉组合体系结构复杂,影响参数众多,本文在前人的研究基础之上增加了副塔倾角和悬索主缆矢跨比两个参数,研究它们对自锚式悬索—斜拉组合体系合理成桥状态的影响程度。随着副塔倾角的增大,悬索段主缆索力减小,背索索力增大,斜吊杆索力增大;对于边跨悬索段,主梁轴向压力和弯矩均减小。随主缆矢跨比增加,悬索段主缆索力、背索索力和斜吊杆索力均减小;主梁轴向压力、弯矩和剪力均减小。
[Abstract]:In recent years, due to the vigorous development of transportation, the requirement of bridge structure system innovation is becoming higher and higher. Bridge workers pay more and more attention to the novelty and mechanical beauty of bridge structure. One of the most remarkable achievements of structural system innovation is the evolution of cable bearing system, cable-stayed bridge and suspension bridge have beautiful appearance, full of shock force, can play the role of iconic building. The cable-stayed bridge is strong and the suspension bridge is charming and slender. The combination system of the two reflects the beauty of the combination of rigidity and flexibility. Compared with the self-anchored suspension bridge, the combined system has better stability against wind, and the height of the main tower is smaller than that of the cable-stayed bridge, while the huge Anchorage is saved, so the combined system is suitable for the poor geological conditions and can improve the economic performance. Be very competitive. Based on the Longgang Bridge in Hanzhong City, this paper studies the self-anchored suspension cable-stayed composite system bridge as follows: 1) this paper studies the reasonable bridge state of self-anchored suspension cable-stayed composite system. On the basis of the current reasonable state of suspension bridge and cable-stayed bridge, this paper introduces a step by step method to calculate the state of the bridge, that is, the model is decomposed into self-anchored suspension cable section and cable-stayed section, and the initial line shape of the main cable is obtained by using the nodal line method. Therefore, the cable element is used to simulate the main cable, considering the nonlinear initial iterative analysis, the reasonable bridge state of the self-anchored cable section is obtained, and the cable force is preliminarily obtained by using the minimum bending energy method, and the influence matrix method is used to optimize the cable-stayed cable force. The cable element is used to simulate the cable, and the nonlinear iteration is carried out to determine the reasonable bridge state of the cable-stayed section. Finally, when the two parts are connected into a whole with the closing section, the original equilibrium state of the two parts is broken, and the new deformation of the structure occurs. The cable force of the suspension cable part and the stay part cable changes, the cable force invariant principle of undeformed pretension is applied to modify the back cable and cable force, that is to say, the cable length of all the back cables and stay cables after the closure is first calculated. Then, the variation of cable length of back cable and stay cable before and after closure is taken into account as non-stress cable length, and then the reasonable bridge state of composite system is obtained by operation analysis. The structure of self-anchored cable-stay composite system is complex, and the influence parameters are numerous. In this paper, two parameters, the auxiliary tower inclination angle and the rise-span ratio of the main cable of suspension cable, are added on the basis of previous studies, and the influence of these parameters on the reasonable bridge state of self-anchored cable-stayed composite system is studied. With the increase of the inclined angle of the auxiliary tower, the main cable force of the suspension cable section decreases, the back cable force increases, the oblique suspension cable force increases, and the axial pressure and bending moment of the main beam decrease for the side span suspension cable section. With the increase of the rise-span ratio of the main cable, the main cable force, the back cable force and the slant cable force of the suspension section decrease, while the axial pressure, bending moment and shear force of the main beam decrease.
【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】：U442.5

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