复杂预制线形钢箱梁顶推计算分析

Calculation and Analysis of Incremental Launching Erection of Prefabricated Steel Box Girders Having Complicated Geometry

某桥为自锚式悬索桥,钢箱梁采用分幅、单向顶推法施工,柔性墩多点顶推工艺。结合该桥的施工监控项目,采用ANSYS有限元分析软件对钢箱梁、钢导梁、顶推平台及临时墩约束等进行模拟,分析钢箱梁顶推施工全过程,并对顶推过程中的局部应力和稳定性进行计算。钢箱梁在顶推过程中,临时墩标高的调整要紧密结合钢箱梁的5段连续预拱度曲线,实际调整中,包括临时墩的沉降测量值。计算结果表明顶推施工控制基本符合结构受力要求。

The steel box girders of a self-anchored suspension bridge were constructed by the one-way incremental launching erection of each separated girder and by the construction technology of multi-point launching on flexible piers. With reference to the construction monitoring and control of the bridge, the finite element analysis software ANSYS was used to simulate the steel box girders, steel launching noses, launching beds and restraint of temporary piers. The whole process of the launching erection of the girders was analyzed and the local stress and stability during the erection were calculated. In the process of the erection of the girders, it was required that the adiustment of the elevation of the temporary piers should closely match the five sections of the continuous pre-cambering curves of the girders, however, in the actual adjustment, the measured values of settlement of the piers were also included. The results of the calculation show that the control of the incremental launching can basically satisfy the requirements for the force conditions of the structure.