七都大桥北汊桥辅助墩合龙方案优化分析

七都大桥北汊桥主桥为五跨连续半漂浮体系叠合梁斜拉桥。为解决三向千斤顶调整墩顶梁段时操作空间受限及支架局部受力不能满足顶梁要求、辅助墩合龙前悬臂梁段起吊角度过大的问题,文中对原方案进行了优化,采用调整索力与线形,改变合龙段梁长,桥面吊机起吊墩顶梁段匹配的方式进行施工控制。结果表明,施工控制过程中结构的塔偏、应力、线形、索力在允许范围内变化,现场实测数据与理论计算结果相吻合,优化方案可行。

Optimization Analysis of Closure Scheme for Auxiliary Piers of Beicha Bridge of Qidu Bridge

The main bridge of Beicha bridge of Qidu bridge is a five span continuous composite beam cable-stayed bridge with semi floating system.In order to solve the problems of limited operation space,insufficient support local stress and excessive lifting angle of cantilever beam section before closing auxiliary pier,the original scheme is optimized in this paper,and the construction control is carried out by adjusting cable force and alignment,changing the beam length of closure section,and matching the bridge deck crane to lift the pier top beam section.The control results show that the optimization scheme is feasible,the tower deflection,stress,alignment and cable force of the structure change within the allowable range during the construction control process.The field measured data are consistent with the theoretical calculation results,and the optimization scheme is feasible.