Improving the progressive collapse resistance of long-span single-layer spatial grid structures

Abstract

The progressive collapse of long-span single-layer spatial grid structures, which are widely applied in public buildings, is a hot research topic in structural engineering. Four substructure experiments were conducted, and two types of failure were observed: strength and stability. Based on the experimental results, a numerical simulation using multi-scale technology was calibrated. A novel method including kinked steel pipe reinforcement and extra member reinforcement was proposed and validated by numerical simulation. Kinked steel pipe reinforcement is a local reinforcement method that prevents strength failure. The shape of the kinked steel pipe was determined through single-member analysis. Simulation results showed that the bearing capacity and deformation were improved simultaneously. The increase in the potential energy induced by member removal was absorbed into the strain energy. Extra member reinforcement is a global reinforcement method that prevents stability failure. Eigenvalue and nonlinear buckling analyses were adopted to locate the extra members. The extra member reinforcement was applied in the anti-collapse analysis of two typical domes. The results validated that extra member reinforcement is a powerful technique for resisting progressive collapse.