Abstract: A spatial nonlinear model is established and the linear and nonlinear analyses of stability on a large-span CFST arch bridge are maken during its construction process and the serving phase through the Nastran structure analysis system. Discussions on various kinds offactors which would afect the stability of a CFST arch bridge are made.As a result.some important conclusions arc obtained ，which may be valuable for the design and construction of such kind of bridge.

Key words: CFST, nonlinear, stability

摘要： 以某钢管砼拱桥为对象，针对大跨度钢管砼拱桥的稳定问题，建立其空间有限元模型；对该大桥在施工过程及 营运阶段的力学性能进行线性、非线性稳定性分析；讨论了影响稳定性安全系数的多种因数；得出的结论对今后该 类桥型的设计及施工具有一定的参考价值.

关键词: 钢管砼拱桥, 非线性, 稳定性