PSI - Issue 78

Stefano Bracchi et al. / Procedia Structural Integrity 78 (2026) 745–752

747

2. Case study 2.1. Building description

The case study building consists of a tuff masonry building, derived from real buildings built around the end of the XIX/beginning of the XX century in Naples. This building is considered to be representative of the existing building stock in the surrounding area of the central station of Naples, for which a detailed soil characterization is available. A configuration of the building retrofitted according to the Italian building code of 1981 and the associated guidelines (MPW 1981a,b) is considered. The configuration without SFSI was studied in previous works and is characterized by the sole intervention of floors stiffening. Fig. 1 shows the numerical model (built with 3Muri software), the plan of one of the stories and a façade.

(a)

(b)

(c)

(d)

Fig. 1. Case study building: 3Muri model (a), plan view and façade (b), example of an existing similar building (c) and subsoil conditions in the area of Garibaldi Station in Naples (d).

2.2. Foundations of the building and subsoil conditions Ground conditions are very variable in the considered area, both horizontally and vertically. From ground surface downward, the subsoil consists of made ground and remoulded ash underlain by alluvial and/or in situ pyroclastic sand (pozzolana), over a base layer of Neapolitan Yellow Tuff. Details of the soil layering and the profile of shear wave velocity, as derived from a cross-hole test in this area, are provided in Fig. 1. Results undertaken by Resonant Column tests carried out on undisturbed samples of Pozzolana or literature data allowed to define the variation of normalized shear modulus - G / G 0 - and damping ratio D (%) with the shear strain γ, for each layer. The foundation system is continuous masonry beam 0.9 wide and 1 m high with an embedment of 1.5 m.