步履式顶推施工中钢箱梁结构受力特性研究  

RESEARCH ON MECHANICS CHARACTERISTIC OF VLADUCT STEEL BOX GIRDERS BASED ON WALKING-TYPE INCREMENTAL LAUNCHING METHOD

作　　者：朱飞[1] ZHU Fei(China Railway 18th Bureau Group Tunnel Engineering Co.,Ltd.,400700,Chongqing,China)

机构地区：[1]中铁十八局集团隧道工程有限公司,重庆400700

出　　处：《建筑技术》2024年第24期3014-3017,共4页Architecture Technology

摘　　要：本研究以温塘村特大桥钢箱梁工程为背景,首先详细设计了步履式顶推施工现场布置、顶推段拼装工艺及顶推施工步骤,然后基于MIDAS/Civil有限元软件分析了钢箱梁顶推施工过程中梁体的最大挠度、最大应力与步履机支反力,校验了顶推支架的强度与稳定性。结果表明当导梁前端顶推至五号步履机时,梁体达到最大悬挑长度,出现最大挠曲;钢箱梁顶推至设计位置时,导梁尾端应力集中明显,建议重点关注该工况的结构监测;钢箱梁的局部拉压受力和顶推支架的一阶屈曲模态特征值均符合稳定性要求。综合来看,步履机的“顶、推、降、缩”交替协同作用有助于提高钢箱梁和支架体系的施工安全。The detailed plan of the site organization before the incremental launching,the assembly procedure of the steel box girder and the steps of incremental launching construction were firstly prepared based on the technical characteristics of the steel box girder of the Wentang Village Extra-Large Bridge.Following that,the maximum deflection,stress and support reaction force of the girder during the incremental launching construction were analyzed based on the MIDAS/Civil finite element software.Further,the strength and stability of the support system were verified to ensure the construction safety.The results indicate that the beam achieves its maximum cantilever length as the guide beam's front end advances towards the fifth step-walking jack,resulting in peak deflection.Notably,when the steel box girder is positioned as planned,pronounced stress concentration is observed at the beam end,underscoring the importance of structural monitoring in such conditions.Furthermore,the characteristic value of buckling mode for the support system complies with the required stability criteria.All in all,the findings indicate that the alternate cooperation of"jacking,pushing,lowering,and contracting"of the four sets of crawler cranes contributes to the enhancing the construction safety.

关 键 词：钢箱梁 步履式顶推 受力特征 有限元分析 

分 类 号：U445.4[建筑科学—桥梁与隧道工程]