Assessment of the efficiency of seismic design for structural robustness of rc structures

Structural robustness is the ability of a structure to resist against progressive and/or disproportionate collapse. Although at present the main structural regulations foresee guidance for robustness, often the designers don't consider directly these requirements; however, in some cases the buildings have been designed to withstand earthquakes, following the capacity design criteria. The aim of this work is to assess the efficiency of the seismic detailing to ensure robustness of structures not directly designed against progressive and disproportionate collapse. The assessment is based on the comparison of two distinct design of the same structure: in the first case the seismic action is considered, while in the second one the seismic action is neglected. Both the structures are subjected to a column removal and their response after this exceptional event is evaluated. Three different configurations are tested removing respectively an internal, an edge and a corner column placed at the ground floor level. The obtained results show the improvement achievable, in terms of structural robustness, adopting seismic detailing, highlighting the importance of a seismicoriented design also in the prevention of collapse due to accidental actions.