Study On Key Technique Of Construction And Monitoring Of Large-span Steel Structure Of Xuancheng Gym

Large-span steel structure is large in span, light in weight, various and graceful in modeling, so that it is widely used in public architecture areas. However, because of its huge volume, variety of structure forms and complexity of stressing, it suffers from higher accident probability during construction stage than normal structures. It is important to study key technique of construction and monitoring of large-span steel structure. Large-span steel structure of Xuancheng Gym is a hybrid structure system which contains prestressed suspen-dome, welding hollow spherical grid and spatial steel pipe truss, so that it’s novel in structure form and complicated in construction technique. To ensure the structure’s quality and safety of construction, simulation analysis and monitoring about its construction is important. In this paper, key technique of construction and monitoring of large-span steel structure is studied in background of monitoring project during construction on large-span steel structure of Xuancheng Gym.Construction scheme of structure is chosen based on features of the gym and conditions of site construction. The structure is simulated and analyzed during installation construction and uploading construction stage with large universal FEM software MIDAS/Gen, the result shows that the construction scheme chosen before is safe and feasible. Monitoring scheme is chosen based on features of structure and result of simulation and analysis. The monitoring is rich in contents and with pertinence, plays an important role in ensuring safety during construction of the structure. At construction stage of steel structure, the structure is kind of "incomplete" structure, and its stiffness is weaker than "complete" structure so that is more likely to be unstable. In this paper, overall stability of structure at construction stage is studied, and result shows that the structure has a relatively low probability to become unstable. This paper studies result of stress monitoring in details, analyzes the goodness of fit between measured values and theoretical values, and the causes of differences between them. This paper also analyzes result of displacement monitoring in details, studies deformation law of the structure at construction stage. The prestressed cables of suspend-dome of Xuancheng Gym are spatial cables so that change of stress in single cable would cause changes of stress in other cables. Therefore, construction of the prestressed cables of suspen-dome is difficult. In this paper, two analysis methods of construction are used to study 3 kinds of stretching construction schemes of the pre-stressed cables, and the 3 construction schemes are compared and analyzed. Simultaneously, main causes of difference between measured values and theoretical values occurs are studied.The study result shows that the construction process of large-span steel structure of Xuancheng Gym meets safety and design requirement basically. The achievements of this paper are representative, and could provide guidance and references for construction and monitoring work of similar structure.