中文摘要：

为了研究钢管初应力对钢管混凝土拱肋极限承载力的影响,针对实际工程中普遍采用的哑铃型钢管混凝土拱肋,考虑中间主应力、材料拉压比、初应力、初始缺陷、矢跨比和长细比等因素的影响,采用统一强度理论和修正的等效梁柱法,推导出一个新的初应力影响系数的计算公式,并建立其极限承载力的统一解。应用提出的计算公式分别对有、无初应力的哑铃型钢管混凝土拱肋的极限承载力进行计算,并将无初应力拱肋的计算结果与相关文献的试验结果及计算结果进行对比。分析结果表明：所提出的计算公式具有较好的精确度,验证了该计算方法的可行性;研究结果可为工程应用提供参考。

英文摘要：

To study the influence of initial stress on the ultimate bearing capacity of concrete-filled steel tube （CFST） arch ribs, aimed at dumbbell shaped CFST arch ribs which have been widely adopted in practical engineering, considering the influence of intermediate principal stress, tension-compression ratio of materials, initial stress, initial geometric imperfection, rise-span ratio and slenderness ratio, a new influence coefficient of initial stress was deduced and a unified solution to the ultimate bearing capacity was established on the basis of the unified strength theory and the modified equivalent beam-column method. The ultimate bearing capacity of dumbbell shaped CFST arch ribs （with initial stress and without initial stress） was calculated by using the proposed formula. The calculated results were compared with those of experiments and related literatures without initial stress. The results indicate that the proposed formula has better calculation accuracy and the rationality of the method has been proved. This study is of great significance to practical engineering.