中文摘要：

以洞庭湖特大桥君山岸引桥为实例,主跨为（75＋3×120＋75）m五跨变截面预应力混凝土连续箱梁,建立菱形挂篮和钢管支架的Midas空间有限元模型,考虑动力冲击系数模拟动态施工过程,分析菱形挂篮和钢管支架的变形和强度特征。结果表明,挂篮底前横梁最大变形值为17.05 mm,满足规范要求;主桁架可简化为平面桁架结构计算杆件内力,横梁和底纵梁均可简化为平面梁单元结构计算杆件内力;主桁架、横梁和底纵梁的压应力和拉应力均满足要求,且富裕度较大。钢管支架结构最大变形值的数值结果为5~7.5 mm,与现场支架预压数据较吻合;钢管支架结构主要受力构件为钢管,横撑和斜撑受力较小。

英文摘要：

According to the approach bridge of Dongting Lake bridge with the main spans of （75＋3 ×120＋75）m, this article built the finite element model of rhombic hanging basket and steel pipe support to simulate the dynamic construction process which considers impact coefficient.The deformation and strength characteristics of rhombic hanging basket and steel pipe support was then analyzed.The results show that：The maximum deformation value of the front beam of the hanging basket is 17.05 mm,which meets the requirements of the code;Main truss can be simplified as plane truss structure to calculate internal forces,and cross beam and the bottom longitudinal beam can be simplified as plane beam element structure;The compressive and tensile stress of the main truss,cross beam and bottom longitudinal can meet the requirements with a large degree of prosperity.The numerical results of the maximum deformation value of steel pipe support are 5~7.5 mm,which is in good agreement with the data of preloading;The steel pipe is the main bearing member of the steel pipe support,and the transverse and the diago-nal brace is secondary.