PSI - Issue 78

Maria Zucconi et al. / Procedia Structural Integrity 78 (2026) 839–844

841

database. For DSt1 and DSt2, which involve exclusively non-structural elements such as infill walls, the repair cost ratios were derived by reinterpreting the results of Del Vecchio et al. (2020) (Vecchio et al. 2020). That study analyzed actual post- earthquake repair costs from the 2009 L’Aquila event, associating them with damage to infill components and usability outcomes recorded via the AeDES form. The costs were expressed in unit terms (€/m) and normalized with respect to the total replacement cost, thus providing a direct estimate of Cr% attributable to non-structural tsunami damage. For DSt3 and DSt4, representing progressive structural degradation of RC members, the Cr% values were obtained from Di Ludovico et al. (2022) (Di Ludovico et al. 2022), which provides average repair costs for EMS-98 seismic damage states. These values were derived from extensive post-earthquake reconstruction data and reflect typical interventions needed for shear and flexural damage in structural elements. The resulting Cr% ranges associated with each tsunami damage state are summarized below (Zucconi et al. 2025): • DSt1: 2% – 15% • DSt2: 7% – 44% • DSt3: ≈62% • DSt4: ≈78% • DSt5: 100% 3. Case study and Damage Uncertainty Integration The preliminary version of the proposed methodology assumes a fixed extent of damage to non-structural components, particularly infill walls at the ground story, without explicitly accounting for uncertainties in their actual distribution or severity. However, real tsunami events often produce highly variable effects depending on flow direction, local topography, and building orientation. As a result, assuming uniform perimeter damage may lead to significant deviations in loss estimates, especially in urban coastal environments with complex geometries and irregular exposure. To address this limitation, the present section introduces a refinement of the model through the integration of uncertainty in the extent of infill wall damage. This refinement is applied to a reference building configuration that reflects the structural characteristics most commonly found in Italian coastal settlements exposed to tsunami hazard — particularly in southern regions such as the Ionian coastline of Calabria, the eastern shores of Sicily, and the lower Salento peninsula in Puglia (TSUMAPS-NEAM Consortium 2018; Basili et al. 2021; ISTAT (Istituto Nazionale di Statistica) 2023). These areas are not only classified as high-risk zones in national tsunami hazard assessments but also share a prevalent building stock composed of mid-rise RC residential buildings constructed without the capacity design criterion, often characterized by non-structural masonry infills. Rather than relying on existing structures, a synthetic yet realistic case is developed to enable controlled variation of key parameters such as building height, number of bays, and the percentage of infill panels affected by inundation. By simulating a range of damage scenarios at ground level, the analysis explores how uncertainty in the extent of non structural damage impacts the repair cost ratio (Cr%), thus quantifying the sensitivity of economic losses to tsunami induced infill degradation. This refinement represents an evolution of the initial framework and lays the groundwork for future applications in regional-scale, multi-hazard loss modeling — especially in areas of southern Italy where tsunami exposure intersects with vulnerable building typologies and dense urbanization. 3.1. Selection of a representative building typology In order to support the analysis of repair cost sensitivity under tsunami-induced damage, a parametric study was carried out on an idealized reinforced concrete (RC) residential building representative of the construction typologies most commonly found in Italian coastal areas. The selected configuration reflects widespread post-1960s urban expansion, where mid-rise RC frame buildings with masonry infills were frequently constructed without seismic detailing or capacity design principles. The reference structure is defined with a regular rectangular layout composed of 3 bays in one direction and 4 in the other, with uniform span lengths of 5.0 meters. The typical floor height is assumed to be 3.0 meters, and the total