Construction monitoring on the unloading process of steel roof for Guilin Liangjiang International Airport Terminal T2

The main building of Guilin Liangjiang International Airport Terminal T2 adopts the steel reinforced concrete frame structure, the central roof uses the spatial solid web arch support and single-shell steel structural system with the largest supporting arch span of 120 meters, and the single-shell steel structural system is connected with the spatial solid web arch through diagonal bracing. The large-span space steel structure of the roof had a large building area, and more than 300 lattice columns were used for temporary support in construction. In the unloading process of steel structure, the deformation and stress of the structure changed greatly. Simulation for all construction steps of the main steel structure, the key steel members and structural locations with large deformations were found out, and the monitoring scheme of deformation and stress of steel structure were determined. The stress monitoring of steel structural was completed by the self-developed wireless stress monitoring system. The deformation monitoring points were automatically searched by the deformation robot, and the three-dimensional coordinates of each monitoring points were measured. The measured results were compared with the initial data, and the deformation of structure was obtained. In the whole process of stress and deformation monitoring, the early warning values were set according to structural analysis and material properties, which could help engineers to make decisions on the structural safety. After the smooth construction of the project, we would find that the monitoring system meted the monitoring requirement during the construction stage, and the result was an important evaluation index for the structure. The research methods used in this paper could be seen as useful reference for construction of similar projects.