Large scale loss assessment using stick-it model: A comparison with actual cost data

The estimation of expected seismic losses at regional scale represents a critical issue for the assessment of the seismic risk and for the evaluation of the seismic resilience of large communities. In a performance-based approach, the assessment of economic losses requires the computation of the building performances in terms of engineering demand parameters such as interstory drift ratios and peak floor accelerations in order to assess the distribution and the extent of the damage experienced by various building components. The Stick-IT model (Stick for Infilled frames Typologies) was recently proposed to predict the response, in terms of engineering demand parameters, for infilled RC building typologies. The Stick-IT is a MDOF system consisting of a series of lumped masses connected by nonlinear shear link elements. The model parameters can be defined for building typologies starting from low-level information that can be easily retrieved at the large scale via image-based processing techniques integrated with information about typical construction features, such as in plan dimensions, the number of stories or the percentage of infills openings and considering the infills consistency. This paper adopts the Stick-IT model within a probabilistic framework to predict damage and expected losses for a set of residential buildings located in L'Aquila town that suffered damage during the 2009 L'Aquila earthquake. By comparing the predicted losses with the actual repair costs, the application shows the advantages and the potentiality of the proposed model when adopted for large scale loss assessments.