(北京市建筑设计研究院，100045)

［提要］以首都国际机场交通运输中心(GTC)大跨箱型钢拱结构为工程背景，以单拱、组拱和整体屋盖钢拱结构为研究对象，采用非线性有限元法分析结构失稳问题。在多种不利荷载组合作用下，研究对应于GTC钢结构体系的理想结构整体稳定性能并得出结构特征屈曲系数的基础上，考虑几何非线性、材料非线性，按最不利原则施加初始几何缺陷，计算结构的非线性稳定屈曲系数，获得相应的折减系数，并讨论了双重非线性对结构整体稳定的影响。同时，数值分析了主拱拱脚处腹板的局部稳定问题，结果说明，在拱脚处需合理设置加劲肋板来避免腹板局部失稳。

［关键词］首都机场；大跨钢拱结构；整体稳定；屈曲；组拱

Stability Analysis of Terminal 3"s Ground Transportation Center of Beijing Capital International Airport/Zhu Zhongyi, Ke Changhua, Qin Kai, Wang Yi, Shu Weinong (Beijing Institute of Architectural Design, Beijing 100045,China)

Abstract:The structural instability problems are analyzed through nonlinear finite element method, taking single arch, multiple arch and complete steel arch roof as research objects, using the large span steel box section arch in Ground Transportation Center(GTC) of Beijing Capital International Airport as background. The research deals with ideal complete stability properties of the GTC steel strucuure system, and gets structural characteristic buckling factor under multiple kinds of worst load combinations. In addition, it calculates structural nonlinear stability buckling factor, and corresponding reduction factors,discusses the influence of structural complete stability due to binonlinear,considering geometric and material nonlinear, and initial geometric imperfection under worst principle. Using numerical method to analyze web local stability problem at the foot of main arch, it concludes that board stiffening rib should be built appropriately at the foot of arch, in order to avoid web local instability.

Keywords:Beijing Capital International Airport; large span steel arch structural; complete stability; buckling; multiple arch

*北京市科技新星项目。