中文摘要：

基于合理的材料本构关系模型,采用有限元法对长期荷载作用下钢管混凝土柱的变形-时间关系曲线进行了计算,并在此基础上对长期荷载作用下钢管混凝土中核心混凝土的徐变系数终值进行了拟合和分析。分析结果表明：在长期荷载作用下,钢管混凝土中核心混凝土的徐变系数终值要明显小于素混凝土;采用0.9作为钢管内核心混凝土的徐变系数终值是合理且偏于安全的。

英文摘要：

Based on the reasonable material models, a finite element （FE） model was developed to calculate the long-term deformation of concrete-filled steel tube （CFST） columns under sustained loading. The predicted re-sults of FE model were in good agreement with those of the experimental ones. Then, the ultimate creep coeffi-cient of core concrete for the CFST column was analyzed. The results show that, under long-term sustained loading, the ultimate creep coefficients of core concrete in a CFST are significantly lower than those of the plain concrete, and it is reasonable and safe to use 0.9 as the ultimate creep coefficient for the CFST column.