DEVELOPING STOREY LOSS FUNCTIONS FOR EVALUATION OF SEISMIC RISK IN ITALIAN RESIDENTIAL BUILDING TYPOLOGIES

Refined and simplified methodologies are generally used to perform seismic loss assessment of existing buildings. The refined methodologies typically refer to probabilistic component-based approaches, which are difficult to be implemented by practitioners. A reliable alternative could be the use of storey loss-based frameworks, which although less complex, still require some improvements in the calibration of its input elements to avoid overly conservative loss estimates. This paper deals with the development of generalised storey loss functions (SLFs) for different Italian residential building typologies, using post-earthquake observational damage data from the 2009 L'Aquila earthquake. Data on real buildings was collected from the Italian price bulletin to ensure that both the building typologies and the cost ratios for structural and non-structural components, with respect to the total construction cost, can be effectively representative of the real features of Italian residential buildings. At the same time, the SLFs were developed as a function of the building's replacement value, estimated using the current average construction cost per square metre in Italy. The adopted fragility models were specifically calibrated for structural and non-structural components commonly found in Italian and Mediterranean-country reinforced concrete buildings. The assumed repair costs were incurred after the 2009 L'Aquila earthquake. The proposed SLFs can be a useful alternative to the simplified conservative loss assessment guidelines currently employed in Italy to plan risk mitigation measures at regional and single-building levels.