高速铁路48m/1600t下承式造桥机结构总体设计

大(同)西(安)客运专线铁路晋陕黄河特大桥48 m简支箱梁预制节段采用下承式造桥机施工.造桥机主要由主结构(主框架、导梁)、主支承(前支腿、中支撑、后支腿)、托架台车倒运机构、节段支撑横梁、起重系统、湿接缝外模板、运梁车系统、液压系统、电气系统等组成,其中主框架是造桥机施工荷载的承重结构.采用ANSYS建立造桥机模型,对满跨加载、导梁最大前悬臂、倒运支腿、过孔工况下造桥机受力、变形及墩旁托架受力进行分析,分析结果表明造桥机组成构件受力及挠度变形均满足使用要求.

Overall Design of 48 m/1600 t Through Overhead Launching Gantry for Construction of a High-Speed Railway Bridge

The precast segments of the 48-m span simply-supported box girders of Jinshan Huanghe River Bridge on Datong-Xi′an Passenger Dedicated Railway were erected by the through overhead launching gantry.The gantry is mainly composed of the principal structures(the main frame and launching nose),main supports(the front,middle and rear support legs),brackets,trolley shifting mechanism,segment support cross beams,hoisting system,wet joint external formwork,girder carrier system,hydraulic system and electric system,of which the main frame of the gantry is the construction load carrying structure.The models for the gantry were set up by the ANSYS,the force conditions,deformation of the gantry and the force conditions of the pier-side brackets under the load cases of loading on a full span,the longest cantilever of the launching nose and shifting of the support legs and traveling of the gantry to next span were analyzed.The results of the analysis show that the force conditions and deflection deformation of different components of the gantry can satisfy the requirements for service.