PSI - Issue 78

Antonio Cibelli et al. / Procedia Structural Integrity 78 (2026) 1221–1228

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Direct damages are interpreted as economic losses resulting from the damage to structural and non-structural ele ments of the building following fire exposure. These include costs associated with repairs or reconstruction. Their quantification refers to data and formulations provided in HAZUS (NIBS, 2003), which allow to quantify the expected value of losses, based on structural vulnerability and economic value of the damaged elements:

= � ( ) 5 =2

(6)

EL STR represents the economic loss related to the repair of the structural system; FV STR is the fraction of the build ing's total replacement value attributed to the structural system; RV B indicates the overall replacement value of the building; PSTR ds is the probability of reaching damage state ds ; STRD ds quantifies the corresponding repair cost, ex pressed as a fraction of the total structural system cost. The indirect damage component includes costs related to operational losses, functional interruptions, and socio-economic impacts (SFPE, 2002). The sum of these components allows the assessment of the overall life cycle cost for each considered fire scenario. The direct comparison between the protected and unprotected structure thus provides an objective basis for evaluating the economic effectiveness of fire protection strategies. 3. Application The methodology is applied to a steel building intended for vehicle storage, which is exposed to a non-negligible fire risk. The structural fragility assessment is conducted considering two configurations: (i) unprotected structure and (ii) structure protected with gypsum-based sprayed fireproof plaster. The objective is twofold: on one hand, to evaluate the technical benefit in terms of reduced fire vulnerability; on the other hand, to estimate the economic advantage of passive protection through a life cycle cost-benefit analysis. 3.1. Description of the typological building The analysed building is a steel warehouse made of S275 steel, intended for vehicle storage, with a rectangular plan (24 × 17 m) and a double-pitched roof (15% slope). The supporting structure consists of transverse trusses made of hollow sections, supported by HEB320 columns, and is braced in both main directions. The design complies with Eurocodes EN 1993 (2005) and EN 1998 (2004).

Fig. 1. (a) transversal section; (b) floor plan of the analysed typological steel building.

The thermo-mechanical analyses are conducted on a central transverse frame, considered representative of the overall structural behaviour, allowing a reduction in computational costs without compromising result accuracy. 3.2. Fire scenarios and fire modelling Since the structure is intended as a parking garage, vehicles represent the main source of fire ignition and propaga tion. Therefore, the scenarios are constructed by considering different combinations of involved vehicles. Because the performance indicators concern both columns and beams, each scenario is analysed twice, varying the fire location: