摘要研究目的：大跨度钢管混凝土拱桥以其特有的自重轻、强度大、抗变形能力强、施工方便和外形美观等优点，被大量地的用于桥梁结构中。本文以一座在建360 m 钢管混凝土拱桥为例，采用通用程序 ANSYS 建立该桥的空间有限元计算模型，分别对该桥进行裸拱状态和考虑拱上建筑共同作用状态下的特征值屈曲稳定性分析、考虑几何和材料双重非线性的极限承载力分析，并对计算结果进行比较分析，给出拱桥极限桥承载力计算的一般性方法。
Abstract：Research purposes:The long span concrete filled steel tubular arch bridge is widely used because of its unique characters of light dead weight，big bearing capacity，good anti － deformation capacity，easy construction and nice appearance． In this paper，taking a concrete filled steel tubular arch bridge with a span of 360 meters as an example，a spacial finite element model was established with ANSYS to separately analyze the eigenvalue buckling stability of the bridge under joint effects of the bare arch and the architectures on it，and the ultimate bearing capacity on consideration of the nonlinearity of the geometry and material． The calculation result was compared and analyzed．The general method was presented for calculation of the ultimate bearing capacity of the arch bridge．
Research conclusions:(1) On consideration of the structure on the arch，the minimum eigenvalue buckling in the analysis result was 13.477，and the eigenvalue buckling of the bare arch in the analysis result was 6.663．Both of them were bigger than 4 and 5 stipulated in the specification．The arch rib met the requirements of the stability inside and outside of the cross － section．(2) The minimum ultimate bearing capacity of the arch bridge in the analysis result was 2.252，and it showed that under the influences of the double nonlinearities and the initial defects of the structure，the safety factor of the bridge under main working conditions was 2.252，meeting the requirements of no less than 2 for the elastic － plastic stability safety factor on consideration of the nonlinear effects of the structure，and the structural design was reasonable．(3) The structures on the arch like the pier columns had the big effect on the stiffness of the bridge，while they had small impact on the ultimate bearing capacity of the arch．(4) The eigenvalue buckling in the analysis result was of a nonconservative calculation result． In the actual process of designing an arch bridge，the influences of the double nonlinearity and initial defects of the structure on the ultimate bearing capacity had to be considered． And the methods introduced in this paper could be as the reference to the similar works．
Pan Youguang ． The Constitutive Relat Ionship of the Core Conerete in Conerete Filled Steel Tubes ［D］． Journal of Civil Engineering in Haerbin University，1989 (1) :37－47．
Zhang Yang，Shao Xudong，Cai Songhai，etc．Spatial Nonlinear Finite Element Analysis for Long － span Trussed CFST Arch Bridge ［J］． China Journal of Highway and Transport，2006(4) : 65－70．
［7］ NAZMY A． S． Stability and Load －carrying Capacity of Three Dimensional Long － span Steel Arch Bridges ［J］． Computers and Structures，1997(6) : 857－868．
Hu Guowei，Zhang Yuning，Zhang Junbing． Research on the Space Stress － distribution Characteristics of Long － span and Complex Structure Bridge during theWhole Construction Process ［J］． Journal of Railway Enginneering Society，2010(3) : 42－48．
2012, Vol. 29 
版权所有 © 2014 《铁道工程学报》编辑部