English：

In response to the technical challenges of the steel roof of Xining Caojiapu InternationalAirport, such as the large height difference of the steel roof, interference from the construction face ofviaduct in the southern grid frame cantilever area, as well as a large number of cast steel joints, a seriesof innovative studies were carried out. Aiming at the problem of horizontal migration of steel structure inthe process of rotating lifting, the mechanism of horizontal migration of grid frame is analyzedsystematically for the first time, and the theoretical model and simplified calculation method areproposed. To address the interference problem of the construction face, a combined construction methodof slipping-lifting was proposed. An innovative equal-strength cast steel joint was designed, whichachieved load distribution by extending the weld lap length, thus realizing the equal-strength connectionbetween steel components of different strengths. The theoretical model and the new type of cast steel jointwere verified through finite element numerical simulation and loading tests. The results show that thetheoretical calculation value of the horizontal migration of grid fame in the rotating lifting process is ingood agreement with the finite element analysis results, with a deviation of only 6%. The combinedconstruction method of slipping-lifting effectively solved the problem of interference from the constructionface of viaduct in the construction of large overhang area of the airport, ensuring the safe and efficientprogress of the project. The new connection joint meets the requirements of equal-strength connection inthe specifications, and the fracture points of the tensile specimens all occurred in the base material arearather than at the connection weak points.