【作者】 郭静；

【导师】 童丽萍；

【作者基本信息】 郑州大学 ， 结构工程， 2003， 硕士

【摘要】 拱式组合体系桥梁是目前广泛采用的一种桥梁结构形式，一方面由于拱式组合体系桥梁结构的复杂性和多样性，现有的工程经验已不能满足设计需求；另一方面对于这种结构体系过去的传统做法是将复杂结构简化成平面结构，这种做法显然忽略了构件之间的空间作用，尤其是沿桥横向存在主要承力构件。因此如何正确模拟拱式组合体系桥梁，进行拱式组合体系桥梁的设计和计算，获得符合实际的受力性能，一直是摆在桥梁工作者面前的一项迫切任务。 本文以广州市中山一桥为背景，采用大型通用有限元程序ANSYS，考虑构件间的空间相互作用，建立了三维的有限元模型，重点对以下几个方面进行深入探讨： 首先，在对复杂的桥梁结构进行三维的有限元模型建立时，梁格法是分析桥梁上部结构比较实用而且有效的空间分析方法。在选用梁格法进行整体分析时，遇到桥面系是单箱双室的箱型梁时，按照抗弯刚度不变且各部分绕着同一中性轴的原则，将一个箱型梁在相应的腹板处简化成3根梁，能够保证剪力的有效传递，而且可以由这划分的3根梁的性能得到箱型梁结构的总性能，这种方法简便易行且能保证工程精度； 其次，本文基于弹性理论，采用有限元法对中山一桥进行了第一类稳定分析。着重对失稳类型、横撑在稳定中所起的作用、吊杆非保向力的作用以及施工阶段的应力和成桥阶段应力的比较、规范中稳定安全系数的规定进行探讨。提出了拱式组合体系桥梁的失稳规律，将吊杆非保向力和构件受力结合起来考虑吊杆对拱稳定性的影响。另外，提出在施工阶段中某些构件的应力有可能比成桥状态的应力还大，需防止在施工状态中构件因强度不足而破坏； 再次，采用于空间迭代法，求解了拱式组合体系桥梁的自振周期和振型，得出该种结构体系的动力特性，深入探讨了动力特性和结构刚度之间的内在联系，提出了把结构的动力特性作为判断结构方案是否合理的重要依据。 此外，本文还就系杆预应力值的确定方法、局部刚度区域的模拟、节点局部有限元分析提出了作者的见解和看法，对解决类似问题得出了一些有参考意义的结论。更多还原

【Abstract】 Arcuated built-up system bridges are one of bridge structural styles, which are used extensively at present. On one hand, because of complexity and diversity of this kind of structure, current engineering experiences have not satisfied design requirements no longer. On the other hand, towards this kind of structural system traditional methods simplify complicated structures into planar structures, these methods neglect apparently spatial action among members, especially those primary bearing load members along lateral direction of bridges. Therefore how to simulate exactly an arcuated built-up system bridge, carry calculation and design of it and obtain behaviors in accord with facts, is a urgent task in front of bridge workers.The paper is based on an arcuated built-up system bridge-Zhongshan No.one Bridge to be built in Guangzhou, adopts the large universal finite element programme ANSYS, takes spatial action among members into account, establishes a three-dimension finite element model, and discusses the following several aspects:Firstly, when three-dimensional finite model of a complicated bridge is founded, a beam-lattice method is a kind of applied and effective spatial analysis method, which is used to analyze superstructures of a bridge. When whole analysis is carried through the beam-lattice method and bridge surface is made of box beams with one box and two cells, according to the principle of constant bending rigidity and every part revolving the same neutral axis, a box beam can be simplified into three beams in the places of corresponding webs. Thus effective transfer of shearing force can be ensured, and global property can be reached through that of three beams, this kind of method is simple and is able to ensure engineering precision;Secondly, the paper is based on elastic theory, adopts finite element method and carries through the first kind stability analysis towards Zhongshan No.one Bridge. Destabilization style of an arcuated built-up system bridge, influence of nonconservative force of hanger rods, comparative between stress value in construction stage and stress value in finished bridge stage,stability coefficients in bridge code, these are discussed deep.Destabilization laws of an arcuated built-up system bridge are provided, nonconservative force of hanger rods and members’ bearing force are integrated in order to consider influence of hanger rods towards arch stability. Besides, stress values of some members are probably higher than those of some members in finished bridge stage. Therefore failure of members should be avoided in construction stage due to insufficiency of strength.Thirdly, subspace iterative method is adopted in the paper, and natural periods and modes of preceding fifteen steps of Zhongshan No.one Bridge are solved, dynamic characteristics of this kind of structural system are obtained, inherent link between dynamic characteristics and structural rigidity is discussed deep, the viewpoint is provided that dynamic characteristics of a structure are considered as important basis whether structural scheme is rational;In addition, the author brings out some own views and opinions about calculational methods of prestress value of different sorts of tie rods, simulation of local rigidity region, foundation of a local finite element model of a node. Some helpful suggestions and conclusions are provided for similar complicated structures.更多还原