多跨连续刚构桥合龙顶推力的优化

Optimization of Closure Jacking Force of Multi⁃span Continuous Rigid Frame Bridge

为了求解多跨连续刚构桥的最优合龙顶推力组合,以成桥后的墩顶水平位移为优化目标,以施工阶段的墩身应力为约束条件,建立多目标线性规划模型,采用模糊数学解法求得最优顶推力组合。以一座多跨连续刚构桥为背景,对不顶推、施加设计顶推力、施加最优顶推力3种情况进行对比分析。研究结果表明:对多跨连续刚构桥施加最优顶推力可有效改善结构线形及内力,且其顶推效果明显优于施加设计顶推力的顶推效果;计算时应考虑实际施工中的合龙温差效应并改进最优顶推力。

Taking the horizontal displacement of the pier top after completion of the bridge as the optimization objective and the stress of the pier in the construction stage as the constraint condition,the multi-objective linear programming model was established,and the optimal combination of closure jacking force of multi-span continuous rigid frame bridge was solved based on fuzzy mathematics method.Taking a multi-span continuous rigid frame bridge as the background,three cases of no jacking,applying design jacking force and applying optimal jacking force were compared and analyzed.The results show that the optimal jacking force applied to the multi-span continuous rigid frame bridge can effectively improve the line shape and internal force of the structure,and its jacking effect is obviously better than that of the design jacking force.The calculation method provided in this paper is simple and fast.The temperature difference effect of closure in actual construction should be considered and the optimal jacking force should be improved.