Toward a Simplified Evaluation of Seismic Repair Costs for RC Buildings with Masonry Infills

The invaluable role played by risk applications in defining emergency management policies in the aftermath of a seismic event or at prioritizing scheme for seismic interventions ensured its centrality within international projects abroad and within the technical literature. Nevertheless, currently a unified approach for the development and application of these procedures is still lacking. Recently, a general and comprehensive approach has been applied to derive global seismic risk maps, assembling some of the available studies for each country in order to evaluate the average annual losses due to ground shaking in the residential, commercial and industrial building stock. On the other hand, the US Federal Emergency Management Agency (FEMA) developed a simplified seismic performance assessment methodology, which, starting from nonlinear response history analyses of buildings, allows to determine damage and losses to individual structural and non-structural components using fragility and consequence functions specifically derived. Such kind of methodologies are very attractive for insurance and risk management strategies, but some efforts have to be still performed to consider the specificity of Reinforced Concrete (RC) buildings typical of the Mediterranean area, generally infilled with hollow clay bricks. In the present work, a comprehensive methodology to evaluate seismic repair cost for infilled RC buildings, requiring as input parameters just the information about the geometry and the results of damage analysis, descending from a nonlinear detailed- or simplified- analysis procedure or even from information collected from post-earthquake inspection. A list of main repair activities needed for refurbishment of infills, partitions and vertical structures and their unit costs are evaluated, whose sum multiplied by the specific quantities affected by damage provide the total repair costs for the whole buildings. The quantification of repair costs for services, which represents a considerable percentage of the total amount, is also taken into account, relating their main repairing activity needed for refurbishment to damage of infills, since they are typically allocated within them for the specific typology studied herein, namely RC buildings infilled with hollow clay bricks. An application of the methodology to a wide dataset of damaged buildings subjected to the April 6th, 2009 L’Aquila (Italy) earthquake is presented. The database is constituted by residential RC buildings located in the Abruzzi region which after the earthquake have been charged to post-earthquake usability assessment procedure. Lastly, the estimated repair costs, evaluated using the information collected after the inspections concerning with the geometry of buildings, together with damage quantification for different structural components, are compared with those reported in the literature to test their reliability.