Empirical damage and actual repair costs on masonry private buildings after L’Aquila earthquake

After the April 6, 2009, L’Aquila earthquake the damage and usability assessment of buildings were evaluated by in situ inspections carried out on each building in the seismic area through the AeDES form. Several Ordinances of the Prime Minister were issued to regulate repair standards and criteria for reoccupancy of private damaged buildings outside the city historical centre of L’Aquila and surrounding municipalities. The government financial support was established on the basis of repairs, local or global strengthening interventions, or demolition and reconstruction and relevant costs, designed and computed by practitioners engaged by owners and checked by a proper commission entrusted by the Government. The paper discusses the data collected on a set of 1,000 residential masonry buildings focussing on usability rating, building characteristics, damage extent on structural components, and Actual Repair Costs (ARC) computed according to practitioners funding requests. Then, the relationship between the empirical damage and ARC is investigated. To this goal, a building Damage Grade (DG) has been computed based on the damage data collected by AeDES forms and according to the European Macroseismic Scale EMS-98. The study points out that the DG are not fully suitable to define a suitable correlation with ARCs. To this end, further suitable index, specifically calibrated to take into account the weight and extent of damage to each structural component on repair costs, is needed.