大跨度悬索桥论文大跨度悬索桥施工阶段静风稳定性分析.doc

大跨度悬索桥论文：大跨度悬索桥施工阶段静风稳定性分析 【中文摘要】悬索桥作为大跨径桥梁的主要型式,结构自重轻,整体刚度低,在强风作用下,容易发生静力不稳定现象。特别在施工阶段,加劲梁梁段之间是临时铰接的,刚度要比成桥状态小很多,静风失稳临界风速更低,且风速可能低于动力失稳临界风速。对施工阶段大跨度悬索桥进行静风稳定性研究,具有一定的工程实际意义。首先,介绍了静风稳定的两类稳定理论,即现行《公路桥梁抗风设计规范》中计算桥梁结构静风失稳临界风速的线性方法和基于有限元理论的非线性分析方法。在考虑结构的几何非线性及静风荷载的非线性的基础上,利用有限元分析软件编制了大跨度悬索桥静风稳定计算程序。其次,以主跨1418m的南京四桥作为工程背景,利用所编程序对该桥成桥和施工状态进行了静风稳定性全过程分析,研究了不同初始风攻角、三分力系数组合、主梁架设方法的影响,并分析失稳临界风速下的结构的非线性行为。最后,在考虑风速空间分布的基础上,对悬索桥成桥和施工状态进行了静风稳定性全过程分析。通过结果的对比分析,不考虑风速的空间分布进行静风稳定分析是偏于安全的。 【英文摘要】As the main type of the long-span bridges, suspension bridge is light and flexible. It is prone to aerostatic instability. Especially in the construction phase, girders were hinged temporarily, the stiffness was much more lower than that of the compeleted bridge so as the critical wind speed of aerostatic instability, and the speed may be lower than that of the aerodynamic instability.There is some engineering significance to study the problem of aerostatic stability of long-span suspension bridge.Firstly, the two kinds of theory of aerostatic stability are introduced, and the linear method prescibed by Wind-resistent Design Specification for Highway Bridge is used to calculate the critical wind speed of aerostatic stability and the nonlinear method is based on the finite element theory. Considering the nonlinearity of geometry and static wind loads, the calculation procedure of aerostatic stability of long-span suspension bridge is performed by finite element analysis software.Secondly, on the basis of the project The Fourth Bridge of Nanjing Yangtze River, main span 1418m, using the procedure above to make a full-process analysis on the aerostatic stability of the compeleted bridge and typical erection phases, considering the effect of different wind attack angles and combinations of aerostatic force factors, and to analyze the nonlinear behaviors of the structure under the critical wind speed.Finally, the effect of spatial distr