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为了给大跨径斜拉桥宽幅钢箱梁的悬拼施工方法提供参考,针对斜拉桥宽幅钢箱梁悬拼匹配过程中横向错缝过大的问题,以港珠澳大桥主体工程中跨径最大的青州航道桥为研究背景,采用大型通用有限元程序ABAQUS建立了青州航道桥悬拼梁段的精细化板壳单元分析模型,并在保证分析精度的基础上尽量采用维度较小的单元类型模拟结构,研究了钢箱梁悬拼匹配过程中悬臂梁段和起吊梁段的横向变形规律,分析了斜拉索索力、悬臂梁段自重、吊机自重与起吊梁段引起的吊机前支点反力的影响程度,探讨了青州航道桥中钢箱梁的合理悬拼匹配工序及现场应对策略。研究结果表明:钢箱梁悬拼过程中的横向变形以横向弯曲变形为主,畸变、扭转等变形较小;起吊梁段引起的吊机前支点反力是引起悬臂梁段和起吊梁段横向错缝过大的最主要因素;传统的从桥面中心线处向两边逐步施焊或通过焊接连接边腹板逐步向桥面中线处焊接的联系方式均不能适应青州航道桥宽幅钢箱主梁的悬拼匹配施工,应优先连接横向刚度较大的边腹板,再通过采取对吊机卸载的方式,待悬臂梁段和起吊梁段横向变形接近一致,完成全截面的临时匹配时;港珠澳大桥青州航道桥的桥面吊机卸载比例为40%。
In order to provide a reference for the method of cantilever construction of wide steel box girder of large-span cable-stayed bridge, aiming at the problem of excessive transverse staggering in the match process of wide steel box girder of cable-stayed bridge, In Qingzhou fairway bridge with the largest span diameter as the research background, a large common finite element program ABAQUS was used to establish a refined plate and shell element analysis model of suspended segment of Qingzhou fairway bridge. Based on the assurance of analysis accuracy, , The lateral deformation of cantilever beam section and lifting beam section during the matching process of steel box girder are studied. The effects of cable force, weight of cantilever beam, deadweight of crane and hanging caused by lifting beam are analyzed. The influence degree of reaction force of the front fulcrum of the machine is discussed, and the matching procedure and the on-site coping tactics of steel box girder in Qingzhou channel bridge are discussed. The results show that the transverse deformation of the steel box girder in the process of cantilever bending is mainly transverse bending deformation, and the deformation such as distortion and torsion is small. The reaction force of the former fulcrum caused by the lifting beam is caused by the transverse direction of the cantilever beam and lifting beam The main factor of the wrong seam is too large; the traditional bridge deck from the centerline to both sides of the gradual welding or welding by connecting the web gradually bridge to the midline at the welding contact can not be adapted to the Qingzhou channel bridge steel master When the beam is suspended and matched, the side web with larger lateral stiffness should be preferentially connected. When unloading the crane, the lateral deformation of the cantilever section and lifting beam section should be nearly the same, and the temporary matching of the full section should be completed. Hong Kong-Zhuhai-Macao Bridge Qingzhou Channel Bridge deck crane unloading ratio of 40%.