格构式超高支墩在桥梁施工中的关键技术

一座双线特大桥采用上承式连续钢桁梁结构,钢桁梁从两侧边墩至主墩悬臂架设在距边墩81 m处,设置高度分别为110.9 m(左侧),133.5 m(右侧)的格构式超高支墩以缩短151.5 m悬臂架设长度。提出一种有效力学分析方法模拟墩梁支撑钢桁梁悬臂架设过程的非线性接触情况,将理论分析模型结合到有限元软件中,运用迭代试算、反馈调节运算方法对钢桁梁架设全过程进行分析,从而得出施工阶段不同环境温度工况下格构式超高支墩支反力与应力。基于钢桁梁与格构式超高支墩结构整体模型分析结果,提出了钢桁梁下落格构式超高支墩施工中的关键技术。

Study on Key Technology of Latticed Super High Pier in Bridge Construction

A double-track super large bridge consists of deck continuous steel truss girder structure.The steel truss girder is cantilever erected from the side piers on both sides to the main pier.The latticed super high pier with height of 110.9 m(left side)and 133.5 m(right side)are set at the place 81 m away from the side pier to shorten the cantilever erection length of 151.5 m.An effective mechanical analysis method was proposed to simulate the nonlinear contact of steel truss cantilever erection process supported by pier girder.The theoretical analysis model was integrated into the finite element software,and the iterative trial calculation and feedback adjustment operation method were used to analyze the whole process of steel truss erection,so as to obtain the reaction force and stress of lattice super high buttress under different environmental temperature conditions in the construction stage.Based on the analysis results of the whole model of the steel truss and lattice super high pier structure,the key technology in the construction of the steel truss falling lattice super high pier was put forward.