The use of Stick-IT model for the prediction of direct economic losses

The Stick-IT model (Stick for Infilled frames Typologies), that is a MDOF system consisting of a series of lumped masses connected by nonlinear shear link elements, was introduced to predict the response, in terms of interstory drift ratio (IDR) and peak floor acceleration (PFA), for infilled RC building typologies. Stick model parameters can be defined starting from low level building geometrical features, easily retrievable at the large scale, such as in plan dimensions, number of stories or the percentage of infills openings and considering the infills consistency. This paper investigates the applicability of Stick-IT to predict the performance and direct economic losses for existing RC infilled frame type buildings. In the framework of a performance-based assessment, the comparison of seismic-loss outcomes provided by using either a detailed finite element model (FEM) (L1) or simplified Stick-IT structural models (L2) are illustrated and discussed. The potential of Stick-IT model is investigated referring to a real building damaged and repaired after the 2009 L'Aquila earthquake and adopting as earthquake input records registered in the proximity of the building. Story-level building damage simulated by L1 and L2 models is compared to real damage, showing satisfactory prediction. The comparison of the real repair costs with those evaluated using L1 and L2 models provides encouraging validation. The application suggests that simplified models such as Stick-IT, despite the low level of information required for its application, can be usefully applied to perform damage and loss scenarios at the large scale. Matlab code to generate the Stick-IT, as well as the example code for the present study, are openly shared through the repository https://github.com/marcogaetanidaragona/Stick-IT.