中文摘要：

总结大跨度连续刚构桥合龙段施工的影响因素及中跨合龙顶推力计算方法,并针对黔江某特大预应力连续刚构桥进行顶推力及顶推位移计算。采用有限元分析方法,分析中跨顶推合龙施工对该桥梁在恒载作用和10 a收缩徐变作用下的主梁跨中挠度、主梁应力、主墩的弯矩及应力状态的影响,证明顶推合龙施工的合理性及正确性。分析结果表明：顶推施工能改善桥墩长期受力状态,避免桥墩墩底出现拉应力,配合预拱度设置,能够有效解决跨中下挠的病害。最后,验证了针对本桥所计算出来的顶推力及顶推位移能满足安全施工及运营阶段的正常使用。

英文摘要：

This paper summarized the continuous rigid - frame bridges, and factors that influence the middle span the calculation method of the jacking jacking construction for long - span force and jacking displacement. Using this method, the jacking force and jacking displacement of a long - span continuous rigid - frame bridge across Qian River were calculated. Finite element analysis was utilized in this paper for estimating the influence of the middle span jacking construction on the mid - span deflection, the stress of main - girder, the bending moment and stress state of the bridge under the effect of dead load and 10 years＇ shrinkage and creep, which proved the rationality and validity of the middle span jacking construction. The results show that the construction method is reasonable and correct. The jacking closure construction method can improve the stress state of the bottom of the main pier. And with the use of pre - camber, it can effectively solve the mid - span deflection disease. Finally, this paper proves that the jacking force and jacking displacement on this bridge can meet the de- mands of safe -construction and normal operation stage.