Design of a Variable-Stiffness Cable-Supported Grid Structure System： a Case Study of Guangzhou Football Park Stadium

Variable-stiffness cable-supported grid structures represent an innovative long-span prestressed structural system that differs from traditional cable-supported structures. By continuously changing the composition of the load-bearing compression rings during the construction phase， the overall structural stiffness at different stages can be adjusted， thereby achieving the goal of subjectively modifying the structural stiffness to cope with complex external conditions in design. This study analyzed and investigated the tension-compression balance ring， internal force distribution differences， construction forming process， aiming to obtain the mechanical characteristics and applicability of the structural system. Taking the Guangzhou Station Football Park Stadium as an actual analysis object， the feasibility of this structural form was examined， utilizing a construction technology without temporary supports to achieve the goal of variable stiffness. Furthermore， an analytical study was conducted on the stadium roof structure， covering the simulation of the construction and forming process， modal analysis， shape-finding analysis， nonlinear buckling， and complex joints. The results showed that the variable-stiffness cable-supported structure system not only achieved subjective modification of the structural stiffness under various construction conditions in the design but also met the requirements of the specifications in terms of stress indicators， demonstrating its safety and reliability.