【作者】 吴向男；

【导师】 梁鹏；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 多塔悬索桥可实现超长超大的连续跨越,突破单一跨径的跨度限制,是应对新世纪跨海联岛工程最可行的方案。但目前国内外已建成的多塔悬索桥实例很少,还没有超千米级的多塔悬索桥建成实例,只有国内的泰州长江大桥和马鞍山长江大桥在建。多塔悬索桥这种结构体系还没有得到大范围的应用的主要原因是目前对这种结构体系的把握和认识还远远不够,存在诸多技术瓶颈。在总结国内外已建成的多塔悬索桥工程实例和已提出的多塔悬索桥设计方案的基础上,对多塔悬索桥的静动力研究现状进行总结。对悬索桥成桥状态、使用状态分析方法和动力作用分析方法进行介绍,在此基础上建立有限元模型对三塔两跨悬索桥与两塔单跨悬索桥进行静动力特性对比分析。按照多塔悬索桥中间塔梁处约束的不同,分别建立铰接体系、漂浮体系、纵向弹性约束体系、竖向支承体系和固结体系的三塔两跨悬索桥有限元模型,并对这五种体系静动力作用下塔梁的内力及位移进行比较分析,研究表明：中间塔处设置一定刚度的纵向弹性约束,一方面可减小静动力作用下的塔底弯矩和塔梁的水平位移；另一方面,由于它不像塔梁固结体系那样有较强大的嵌固刚度,外荷载在主梁处产生的弯矩更接近于漂浮体系,远小于固结体系,因此应作为推荐体系。对边中塔均设置弹性索、边中塔均设置阻尼器、中塔设置阻尼器边塔设置弹性索、中塔设置弹性索边塔设置阻尼器四种塔梁附加约束装置(阻尼器和纵向弹性索)布置形式分别建立有限元模型进行参数化分析,得到这四种布置形式在静动力作用下的结构内力、位移随弹性刚度和阻尼参数的变化规律。研究表明：边中塔均设置阻尼器,静力作用下梁端位移过大；边中塔均设置弹性索,地震作用下边塔底弯矩最大；阻尼器和弹性索组合使用是较好的选择。更多还原

【Abstract】 Multi-tower suspension bridges can realize the continuous super-long-span crossing and breakthrough the length limit of single span, which is the most feasible project in the cross-sea projects in the new century. But now, there are only a few construction examples, none of which are over 1000m all over the word. The 1080m Taizhou Yangtze river bridge and Ma an Shan Yangtze river bridge in China are under constructing. The main reason why this structural system has not been widely applied is that the grasp and understanding is not enough for the structure and there are many technical bottlenecks.Based on the summary of all-ready built examples and proposed design projects in domestic and abroad area, the problems on the actual application process are analyzed and the existing static and dynamic research situation are summed up.The calculation methods are summed up, based on which a multi-tower and a two-tower suspension bridge finite element models are erected to analyze the difference between their static and dynamic characteristics.Finite element models of hinge system, floating system, the longitudinal elastic restraint system, the vertical support system and the consolidation system are established. Through comparative analysis of the five systems, the main conclusions are got as follows:if a certain stiffness of longitudinal elastic restraint are set between the middle tower and the girder, it can decrease the bending moment of the column bottom and horizontal displacement of the girder under the action of static and dynamic force, besides, the bending moment of the girder is less than the consolidation system, it should be the recommended system.Finite element models of all elastic link devices, all dampers, center elastic link devices sides dampers, center dampers sides elastic link devices are established. Through parametric analysis on these four systems under the action of static and dynamic forces, some conclusions are got:The horizontal displacement of the girder is too large under the action of static forces in the condition of all dampers, The bending moment of the side tower bottom is too large under the action of dynamic forces in the condition of all elastic link devices, the two binding systems are undesirable, dampers and elastic link devices combination is a better choice.更多还原