LAUSR

Abstract Long-span single-layer spatial grid structures are widely applied in public buildings. Given their long-span and single-layer characteristics, they can easily collapse during accidental events. In this study, a commonly used reinforcing technology was tested on four substructures that were abstracted from single-layer spatial grid structures. Although a fixed end between the member and joint was constructed, the method is not ideal to improve progressive collapse resistance. Therefore, the optimisation method was modified in two aspects to consider different failure mechanisms. First, a double-layer member was used to improve the stability performance. This realised a ductile failure process because unpredictable buckling is converted to ductile failure. Second, an unbonded member was used for optimisation relative to strength failure. The presence of the embedded pipe produced two plastic areas to promote rotation ability. The aforementioned modified optimisation method is favourable for energy dissipation, and thereby improves the performance of single-layer spatial grid structures with respect to stability and strength failure.