In plane performance of RC infilled frames under seismic actions: Experimental versus code provision values

Recent Italian seismic events highlighted the high vulnerability frequently shown by non structural elements, especially masonry infill walls, whose severe damage caused heavy socio-economic effects. In the framework of performance-based design, NTC2008 Italian seismic code defines different limit states considering both structural and non structural elements. Specifically, for non structural elements subjected to in-plane actions, different inter-storey drift thresholds relevant to the Damage Limit State (SLD) and the Usability Limit State (SLO) are provided, although the latter is prescribed only for buildings having a remarkable impact in case of seismic event (e.g. schools) or strategic role in the emergency management (e.g. hospitals). In the paper, in order to verify the provisions given in the Italian code, the drift values relevant to the SLD and SLO Limit States have been compared with the results deriving from some experimental studies. Experimental data also permit to define a threshold value relevant to the Life Safety Limit State (SLV), which is not provided in the current version of the Italian code.