Numerical investigation on load redistribution capacity of flat slab substructures to resist progressive collapse

• Published in: Journal of Building Engineering Vol. 29; p. 101109
• Main Authors: Weng, Yun-Hao, Qian, Kai, Fu, Feng, Fang, Qin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2020
• Subjects: Flat slab substructures; Load resisting mechanism; Progressive collapse; Punching shear; Quasi-static; Flat slab substructures; Progressive collapse; Quasi-static; Load resisting mechanism; Punching shear
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2019.101109

To study the load redistribution capacity of reinforced concrete (RC) flat slab structures subjected to a middle column loss scenario, high fidelity finite element (FE) models were built using commercial software LS-DYNA. The numerical models were validated by experimental results. It is found that the continuous surface cap model (CSCM) with an erosion criterion considering both the maximum principal and shear strain could effectively predict the punching shear failure at slab-column connections. The validated FE models were employed to investigate the effect of boundary conditions, amount of integrity reinforcement, and slab thickness on the load redistribution capacity of flat slab structures. Furthermore, multi-story RC flat slab substructures were built to capture the load redistribution behavior of different floors. Parametric studies indicate that ignoring the constraints from surrounding slabs may underestimate the load redistribution capacity of the flat slab substructures. Therefore, it is suggested that in future numerical or experimental studies, rigid horizontal constraints should be applied at the slab edge of the substructure to well represent the constraints from surrounding slabs. In addition, it is also found that the amount of integrity reinforcement would significantly affect the post-punching performance of flat slab structures. It is suggested that the minimum integrity reinforcement ratio should be 0.63%. •Progressive collapse behavior of multi-panel flat slab structures to resist progressive collapse was assessed.•The effects of boundary conditions on load resisting mechanism of flat slabs were quantified.•The reliability of single-storey substructures to equivalently study the behavior of multi-storey buildings was evaluated.