双吊机悬臂吊装四点起吊快速精调施工方法

Fast Precision Construction Method of Four-point Lifting for Double-crane Cantilever Hoisting

摘要:

基于钢箱梁节段4点起吊的力学平衡原理，根据吊装节段4点吊装状态的姿态平衡特性，提出分离纵坡与横坡2个正交变量的快速精调定位方法，确定精调施工先调整纵坡后调整横坡的正确操作顺序。工程实例应用于九江长江二桥江心侧的钢箱梁悬臂拼装施工匹配定位施工，节段就位误差小于2 mm，钢箱梁吊装合龙前桥梁线型的控制精度超过L/10 000，梁段拼接无尖角，线型平顺。结合实际，给出了应用纵、横坡正交变量分离法精调宽大节段悬臂吊装施工注意事项。

Abstract:

Based on the mechanics balance principle of four-point lifting for steel box girder segment, and according to the attitude balance characteristic of four-point hoisting state of hoisting segment, a fast precision positioning method is proposed to separate vertical slope and transverse slope orthogonal variables. The correct operation sequence of adjusting the vertical slope first and then transverse slope is determined. The engineering example is applied to matching positioning construction of the cantilever assembly of the steel box girder at the center side of Bridge II of Yangtze River Bridge in Jiujiang. The error of segment positioning is less than 2 mm. The control precision of the bridge alignment before the steel box girder is hoisted and closured is over L/10 000. The beam is spliced without sharp corners, and the alignment is smooth. Combined with the practice, the matters needing attention in the cantilever hoisting construction of precision wide segment by using the separation method of vertical slope and transverse slope orthogonal variables are given.