Dimensioning of Flat Slab Structures for Column Failure

Since the 1970s, structural engineers deal with the hazard scenario of a column failure. Until now, different research papers and guidelines on how to deal with this hazard scenario exist, but they contain only little practical information for structural engineers. Therefore, most structural engineers still do not know how they can adequately design a structure to cope with a column failure. By studying an example, this paper shows how the structural analysis and the dimensioning can be performed for flat slab structures made of reinforced concrete. Because of the rapidity of the event column failure, a dynamic structural analysis has to be performed. This analysis should consider physical and geometrical nonlinearities because a flat slab structure exhibits large deformations after a column failure. However, damping and strain-rate effects play a minor role and do not have to be considered in the structural analysis. Developing nonlinear structural models is a time-consuming task, but for column failure one-storey models are sufficient and therefore no model of the whole building is needed. An example, described in this paper, shows that with an increase of 5% of reinforcement a flat slab structure can be strengthened to survive a failure of one of its columns.