大规模索支撑桥梁钢塔节段预拼的计算机三维仿真

3D Simulation of Steel Tower Segment Preassembly of Large-Scale Cable-Supported Bridge

大规模索支撑桥梁钢塔建设的难点之一是钢塔拼装的精度控制。为使钢塔拼装精度满足设计要求,针对钢塔节段的制造和预拼,依据6D最小二乘法原理及高斯误差累积传递理论,开发任意形状塔柱的钢塔预拼计算机三维仿真技术。该技术解决了由于场地限制而不能进行全塔预拼精度验证的问题,可以识别钢塔节段几何特征并给出单节段制造误差,实现钢塔柱3D预拼和整体预拼线形的计算,在控制参数超标时给出警告,减少误差的积累,有效指导塔柱节段的机加工。该技术在南京三桥钢塔的节段制造和预拼的成功应用,确保了南京三桥钢塔拼装精度达到设计要求。

One of the difficulties in the construction of large-scale cable-supported bridge is the precision control of the steel tower assembly. Focusing on the fabrication and the preassembly of steel tower segment and according to 6D least square method and Gaussian error propagation theorem, 3D simulation technique for the steel tower preassembly of the steel column with arbitrary shapes was developed in order to meet the design requirement for the assembly precision of steel tower. The technique solved the problem that the preassembly precision of the whole steel tower cannot be validated because the limit of ground condition. The geometrical character of steel tower segment can be identified and the 3D preassembly of segments can be realized in computer. Also, the technique can calculate the fabrication error of single segment and whole preassembled steel tower. At the same time, it gives alarm when the controls parameters exceed standards. So the errors can be reduced and the direction of the mechanical cutting can be given. The technique was successfully used in steel tower shape precision management in fabrication and construction of Nanjing 3rd Yangtze River Bridge and the satisfying result was achieved.