Analytical Study of Flat Slab Collapse Mechanisms due to Overloading in a Cluster of Exterior Panels

摘要

Analytical equations found in the literature to give the ultimate load of folding, punching shear and local slab collapse mechanisms have been generally derived assuming a uniform load on all flat slab panels. Regarding that these formulas are not able to consider the impact of unbalanced bending moment due to partial loading, they cannot be applied to evaluate scenarios like overcrowding during operation and change of occupancy. This paper categorizes various collapse modes due to overloading in a cluster of exterior panels as well as presenting analytical equations for the ultimate loads using virtual work method and yield line theory. The study also introduces two novel local slab collapse patterns around interior columns located at the corner of overloaded area. Predicted ultimate loads indicate that flat slabs on a square column grid are expected to be more prone to punching shear and asymmetric local modes around the internal columns supporting two adjacent overburdened panels compared to other column locations.