Prediction of ultimate earthquake resistance of gravity-load designed RC buildings

This research investigates the ultimate earthquake resistance of typical gravity-load designed (GLD) RC moment resisting frames, in terms of ultimate energy absorption/dissipation capacity (UEAC). Inelastic response analyses of six frames, based on the realistic hysteretic behaviour of RC members, are carried out. It is demonstrated that the UEAC of this type of frames is approximately one half of the demand level. From the results, a simple formula is proposed for predicting the UEAC of GLD RC frames under seismic actions. The new formula can be used in an energy-based seismic design procedure, for determining whether and to which extent to seismic upgrade this type of structures.