大跨度钢斜拉桥施工过程线形控制

Linetype Control for Construction of Long-span Steel Cable-stayed Bridges

运用几何非线性分析理论,综合考虑斜拉索垂度效应、梁柱效应和大位移效应,对大跨钢斜拉桥施工过程线形控制进行数值模拟研究.采用多段短索桁架单元模拟长索的非线性效应,通过改变单元的无应力长度实现索的多次张拉.根据新增构件的不同激活方式,提出将施工过程模型分为切线安装、平行安装和建模位置安装3类,其中切线安装和平行安装用于施工过程分析,建模位置安装用于施工控制中的反拱分析.考虑几何非线性多次迭代计算安装线形,采用稀疏矩阵算法求解有限元方程.基于以上原理编制了大跨钢斜拉桥非线性分析及施工过程线形控制模拟软件BINAS,通过苏通大桥实例验证了该方法具有较好的计算精度和适用性.

To obtain the construction linetype of long-span steel cable-stayed bridges accurately, the paper presents a numerical simulation and control technique by taking geometrical nonlinear effects into consideration. Multiple- short truss elements are used to model the sag effect of long cables. The simulation of multiple tensioning of long cables is realized by adjusting unstressed length of cables successively. Different activation modes for new generated components are introduced for different purposes that the tangent and parallel modes are suitable for construction process analysis, and the original position activation mode is used for the linetype control analysis. The sparse matrix algorithm is adopted to speed the simulation. The software of construction linetype control simulation for cable stayed bridges, BINAS, is compiled. The computational accuracy and the effectiveness are verified in the example of the Sutong Bridge.