顶推施工中临时墩位置和主梁节段长度优化研究

Research on optimization of temporary pier position and girder segment length in the incremental launching construction

针对红水河特大桥贵州岸钢梁顶推施工过程中临时墩位置和主梁顶推节段长度的优化,为使主梁在顶推过程中弯矩最小且梁体的安装累积误差最小,应选取最优的临时墩位置和主梁顶推节段长度。通过构造评价函数,将多目标优化转化为单目标优化,并采用综合权重法对各目标函数的权重进行分配,以确定最优的一组临时墩位置。在此基础上,构建数学模型,得到最优的一组主梁顶推节段长度为(10.8+26.2+50+50+50+50)m,优化后的安装误差比原设计方案减小43.5%。通过MIDAS/Civil建立有限元模型模拟,最不利工况的计算结果表明:优化后因安装误差引起的最大应力比原设计方案减少42.9%,优化效果显著,说明本文方法行之有效。

This paper studied the optimization of the temporary pier position and the length of the girder segment during the incremental launching construction of the Red River Bridge in Guizhou.In order to minimize the bending moment of the beam and the cumulative error in the process,the optimal temporary pier position and the length of the girder segment should be selected.In this paper,the multi-objective optimization was transformed into a single-objective optimization by constructing an evaluation function,and the weights of each objective function were allocated by using the comprehensive weight method to find the optimal set of temporary pier position.A mathematical model was constructed to find the optimal set of girder segments with a length of(10.8+26.2+50+50+50+50)m,the optimized installation error was reduced by 43.5%compared to the original one.The finite element model established by MIDAS/Civil simulated the most unfavorable working conditions.The results show that the maximum stress caused by installation errors is reduced by 42.9%compared with the original design,and that the optimization effect is significant.It shows that the method proposed in this paper is effective.