【摘要】 针对异形钢箱拱肋在吊装施工过程中的力学分析和吊耳设计问题,以京雄高速永定河特大桥为工程背景,建立异形拱肋节段在吊装施工中的有限元模型,根据约束点反力最小原则对模型边界条件的施加方案进行分析和比选,计算出拱肋节段的吊带张力。进而推导吊装角度的计算公式,通过吊带张力和吊装角度确定出吊耳的设计荷载后对吊耳结构进行尺寸优化,并对优化后吊耳结构和拱肋结构进行了强度分析,给出了拱肋局部加固方案。分析结果表明,采用有限元法计算出的吊带张力可为吊耳位置的布置、吊带吊具的选型和吊耳的设计提供参考;优化后的吊耳在满足强度设计要求的同时减重率达33.55%,确保了异形钢箱拱肋结构在吊装施工中的安全,降低了吊耳的制作成本。更多还原

【Abstract】 Aiming at the mechanical calculation and lug design of abnormalshaped steel box arch ribs in the process of lifting construction, Yongding River bridge on the Beijing-Xiongexpressway is taken as the engineering background. The finite element model of the abnormal shaped arch rib segments in the lifting constructionis established. Then, the application scheme of the boundary conditions of the model is analyzed and compared according to the principle of minimum reaction force at the constraint point.The sling tension of the arch rib segments are calculated by finite element method. Subsequently, the calculation formula of the lifting angles of the slings is derived. After the design load of the lug is determined by the sling tension and lifting angle, the lug structure is optimized in size. The optimized design of the lug structureis implemented. Finally, the strengths of the optimized lug and the arch ribstructures are analyzed. Hence, the local reinforcement scheme of the arch rib is given. The analytical results show that the sling tension calculated by finite element method can provide reference for the arrangement of the lug position, the selection of the sling spreader and the design of the lug. The optimized lug can meet the strength design requirements and the weight reduction rate reaches 33.55%,which ensures the safety of the abnormal shaped steel box arch rib structure in lifting construction and reduces the production cost of the lifting lug.更多还原