【摘要】 为明确结形撑安装过程中的变形机理及其影响因素,针对港珠澳大桥青州航道桥索塔"中国结"形撑构造异形,杆件倾角大,栓接、焊接混合施工工艺等特点,采用ABAQUES进行了结形撑安装过程的敏感性分析、焊接施工接口姿态影响分析及安装过程变形精细化分析,基于DFLUX子程序及双椭球热源模型编制了热分析子程序,并进行焊接温度场分析,将焊接温度场分析结果采用顺序耦合的方式读入应力-应变场模型进行了焊接收缩量分析。结果表明:对于港珠澳大桥结形撑T2件安装,塔柱双向温度梯度、整体升降温为敏感因素,临时荷载、临时横撑数量为不敏感因素;对于T1件安装,敏感因素仍为塔柱双向温度梯度、整体升降温,临时荷载为不敏感因素,拆除塔顶第1根横撑时影响较小,拆除2根横撑时影响较大;进行结形撑对接施工时,焊缝收缩量与焊缝根部宽度呈线性关系,通过分析结果拟合得到了二者的关系曲线,可供实际施工中使用;结形撑构件J1,J2,J3吊装过程中,塔柱及吊装件变形量小于1mm,可认为其不影响安装精度。更多还原

【Abstract】 In order to identify the deformation mechanism and affecting factors during the cross bracing installation,aimed at the characteristics of the"Chinese Knot"in the Qingzhou Channel Bridge of Hong Kong-Zhuhai-Macao Bridge engineering which involve special shape form,large member angle and the mix of bolting and welding construction,by using the ABAQUS,the sensitivity analysis during the installation process, welding interface attitude analysis and deformation delicate analysis in assembly process were carried out.Based on the DFLUX subroutine and double ellipsoid heat source model,the heat analysis procedures were programmed for welding temperature field analysis and the analysis results were written into the stress-strain field model to analyze the welding shrinkage by sequential coupling.The results show that the tower temperature gradients and the whole temperature fluctuations are sensitive factors for the T2 installation of Hong Kong-Zhuhai-Macao Bridge,while temporary load and the number oftemporary transverse brace are insensitive factors.For the T1 installation,the tower temperature gradients and the whole temperature fluctuations are still sensitive factors,and temporary load is the insensitive factor.The demolitions of the first temporary transverse have little impact,while the demolitions of the second temporary have a large impact.In the butting construction of the cross bracing,the relationship between welding width and the welding shrinkage is linear,and their relationship curves can be obtained through fitting the analysis results,which can be used in practical construction.In the J1 to J3lifting processes,the structure deformations of pylon and lifting components are less than 1mm,which can be considered as an unaffected factor for installation accuracy.更多还原