Assessing Building Reparability as a Function of Performance Loss and Costs: An Application for the L'Aquila Earthquake

One of the most controversial problem in the aftermath of damaging earthquakes is the lack of agreed and transparent policies for acceptable levels of safety to be considered, together with costs, as effective variables influencing reparability decisions and re-construction policies. This paper proposes a rational method, coupling the Performance Loss (PL), obtained with simplified analyses for Reinforced Concrete (RC) building classes, with available cost database, to gain insight on the convenience of repairing buildings that have been damaged by an earthquake. RC plane frames models, representative of existing building classes of varying storey number and construction age, are obtained with simulated design and taking into account the variation of mechanical and structural properties within each class. PL, that is a measure of deteriorated seismic performance for buildings having sustained damaging earthquakes, is determined with a mechanism based analysis applied to the structure in its intact and damaged state. Damaged structure is modeled after suitable modification, depending on the global spectral based ductility demand for the equivalent Single Degree of Freedom (SDOF) system, of plastic hinges for the elements involved in the mechanism. The cost database accounts for the repair costs of more than 1900 RC buildings that were damaged after the 2009 L’Aquila earthquake. The first application presented here shows that it is possible to relate PL and repair costs for RC building classes and demonstrates the viability to use the proposed approach as a simplified tool for preliminary decisions on reparability.