Abstract: The Geiger type and Levy type composite cable dome structure system is adopted in Shunde Desheng Sports Center Gymnasium. The plane projection is ellipse. The clear span of the cable dome in the long axis direction is 124 m, and the clear span of the cable dome in the short axis direction is 105 m, which is the largest cable dome structure with closed metal roof in China. In order to investigate the mechanical properties of cable dome structure with bucket screen after local cable(bar) breaking or relaxation, the progressive collapse analysis of cable(bar) after breaking or relaxation was carried out by using the finite element nonlinear dynamic analysis method. This paper expounded the collapse failure criterion of cable dome structure from the component level and structural system level, and finally determined the collapse failure criterion of structural system level based on the deformation standard and the development mechanism of plastic hinge of residual components after failure. Firstly, it took the failure of the key components of the third ring cable and related inclined cables and braces with large stress as an example, the nonlinear dynamic continuous collapse analysis of the calculation model with or without heavy-duty bucket screen was carried out, and the mechanical properties of the collapse process under the two working conditions were compared. Secondly, the nonlinear dynamic cable breaking analysis of single cable(bar) or multiple cables(bars) at different positions was carried out on the basis of heavy-duty bucket screen, and the mechanical effects of key components at different parts in the structural system were compared. Finally, based on the calculation model with heavy bucket screen, the cable force relaxation analysis of different parts was carried out to investigate the mechanical response of cable members in different degrees of relaxation.
The calculation results show that the combined cable dome structure of Geiger type and Levy type has good resistance to continuous collapse, and the suspended bucket screen, as a centralized suspension mass, has a certain impact on the dynamic response of the structure after cable breaking. By considering the cable breaking analysis at different positions, it is found that the ring cable has the greatest impact on the structure, and the structure still has good resistance to continuous collapse after cable breaking. In order to improve the progressive collapse ability of ring cable in practical engineering design, the design idea of double cable or four cable can be adopted in actual engineering. The structural safety reserve of the structure under accidental load also can be improved.