PSI - Issue 78

Ciro Del Vecchio et al. / Procedia Structural Integrity 78 (2026) 913–920

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Fig. 4). The results show that for the four-floor and two-floor buildings, a reduction in the repair cost of 20-40% due to the FRP strengthening can be observed from a return period of 475 years and 975 years, respectively (see Fig. 4 (a) and (c)). Furthermore, the mean total costs estimated for the as built and retrofitted configurations are comparable for the return period where the probability of occurrence of collapse is null. For the three-floor building, on the other hand, the comparison shows that the costs for the as-built configuration are always higher than the estimated costs for the retrofitted configuration (see Fig. 4 (b)). This result highlights how the FRP strengthening solution under moderate-to-severe intensity earthquakes can significantly reduce the damage and the related costs. 5. Conclusions This paper presents the preliminary results of analysis performed on a dataset of RC buildings typical of the Italian construction standard. The simplified loss assessment framework presented herein is used to perform the analysis, considering the as built and the retrofitted configurations of the selected buildings. The repair costs estimated at component level for a return period of 2475 years are presented for the as-built configuration. Then, the mean total costs estimate for all return periods are compared with the reconstruction costs. In addition, the costs at the return period of 2475 years are compared with the actual repairs cost. Finally, the analysis is performed for the retrofitted configuration to quantify the benefits of FRP strengthening in terms of cost reduction. The main results of this study can be summarized as follows: • Most of the repair costs (between 70 and 90%) estimated for the selected buildings are related to drift-sensitive components with 30-50% of costs associated with the structural components (i.e., joints and stair) and 45-70% associated with non-structural components (i.e. infills and partitions). This remarks on the need for retrofit solutions to reduce the damage of these components and the associated losses. • The probability of collapse affects the costs of the buildings. This is observed in terms of mean total costs with a significant increase in the costs when the probability of collapse increases. • The comparison in terms of mean total costs estimated for the as built and retrofitted configurations of selected buildings confirmed the effectiveness of FRP strengthening. From the results, a significant cost reduction is observed from moderate to severe intensity earthquakes associated to ultimate limit states. Further developments and validation are needed to extend the results to other regions with different construction standards. Acknowledgements The activity of this paper fall within the framework of the DPC-ReLUIS research project 2022-2024, WP5 :” Integrated and sustainable intervention for existing constructions ”. References ATC (2018). FEMA P-58: Seismic performance assessment of buildings Volume 1 - Methodology (Vol. 1, Issue December). https://doi.org/10.4231/D3ZW18S8N Bal, İ., Crowley, H., Pinho, R., & Gulay, F. (2008). Detailed assessment of structural characteristics of Turkish RC building stock for loss assessment model. Soil Dynamics and Earthquake Engineering , 28 , 914 – 932. https://doi.org/10.1016/j.soildyn.2007.10.005 Cardone, D. (2016). Fragility curves and loss functions for RC structural components with smooth rebars. Earthquake and Structures , 10 (5), 1181 – 1212. https://doi.org/10.12989/eas.2016.10.5.1181 Cardone, D., & Perrone, G. (2017). Damage and Loss Assessment of Pre-70 RC Frame Buildings with FEMA P-58. Journal of Earthquake Engineering , 21 (1), 23 – 61. https://doi.org/10.1080/13632469.2016.1149893 CEN. (2005). Eurocode 8: Design of structures for earthquake resistance - Part 1: general rules, seismic actions and rules for buildings. Computers & Structures Inc. (2016). CSI ETABS v.2015. In SAP2000 Reference Manual (Issue July).