The steel structure of the new T3 terminal of Lhasa Gonggar International Airport in Tibet was topped off on the 27th, marking the completion of the main structure, the completion of the overall frame construction, and the project has entered the stage of decoration. The roof of the T3 terminal building is in the shape of lotus petals and the process is mainly steel structure roof truss. To ensure the supply of steel structure materials such as truss, radial bearings, rods, etc. The purchase of 10,000 tons of steel was completed within one month. The steel materials used for the on-site steel structure construction were all shipped from Chengdu via the Qinghai-Tibet line, passing through Xining and Golmud, crossing the Tanggula Pass, and arriving at Gongga Airport. The transportation distance exceeded 3,000 kilometers, and the total number of vehicles reached more than 330 times.
The height of the land-side ridge of the main roof in the central area of the T3 terminal building is 31.960m～44.736m, the circular projection length is about 314m, the radial direction is about 132m, and the maximum span is about 58.7m. The axially stressed steel truss structure system is adopted, and the trusses are arranged in layers along the circumferential direction. The vertical members supporting the main roof of the central area are tree-shaped bifurcated columns. The bifurcated column at the upper end of the tree-shaped column adopts shuttle-shaped round steel pipe rods hinged at both ends, which mainly bear axial pressure; the lower part of the tree-shaped column is a steel tube concrete column, which is connected with the internal floor structure of the terminal building.
In the construction phase, in collaboration with the steel structure implementing unit, relying on the design concept and the temperature sensitivity of the steel structure material, the temperature difference when the truss is closed is accurately controlled by calculation to be less than 25°, and the overall deformation of the steel roof is guaranteed to be within the design allowable range, thus achieving the smooth implementation of the project.