PSI - Issue 78

Franco Braga et al. / Procedia Structural Integrity 78 (2026) 2184–2191

2185

1. Introduction The earthquake of the night of August 24, 2016, devastated the town of Amatrice, causing widespread destruction of buildings and a significant number of injuries and loss of life. The presence of two accelerometric stations — one from the RAN network, named AMT, located at the western entrance of the town beneath the “morphological terrace” of Amatrice, and one from the Civil Protection Department network, located inside the “Romolo Capranica” School, named AMTS— allowed for precise knowledge of the seismic signal that struck the town.. In this work, after defining the peculiar characteristics of the earthquake through the analysis of the recordings from the two aforementioned stations, a numerical model of the masonry building located at Piazza Sagnotti 1 — situated a short distance from the AMTS accelerometric station, and which suffered a generalized collapse as a result of the event — was implemented to illustrate the severity of the stresses imposed on the buildi ng’s load -bearing structures by the 2016 earthquake. Using the same numerical model, a seismic retrofitting intervention was then designed to bring the building into compliance with the italian seismic code in force at the time of the event (NTC2008 D.M. 01.14.2008), demonstrating that, even if such an intervention had been implemented, the August 24, 2016 earthquake would still have critically stressed the structure. 2. Description of the building The building, located at Piazza Sagnotti 1. in Amatrice, consisted of a basement level, three floors used for residential purposes, and a pitched roof. It was constructed on shallow foundations with a masonry structure. Figure 1a shows the general plan of the town of Amatrice, identifying and locating: i) the building in question, ii) the AMTS accelerometric station, located approximately 100 m from the building, and iii) the AMT accelerometric station. Figure 1b shows the building prior to its collapse. a b

Fig. 1: (a) General plan of Amatrice (Google Earth); (b) View of the building, before the collapse, from Via Madonna della Porta.

3. The event of 08.24.2016 3.1. “Near Fault” earthquakes

The earthquake in question, due to a hypocenter depth of less than 10km, is one of those already defined in the 90s by US codes (UBC-1997) as "near fault earthquakes". In the UBC (and in other international technical regulations) the treatment of this type of earthquakes is motivated by the fact that, the reduced depth of the hypocenter produces, in addition to a limited dissipation of energy due to the reduced power of the layers of soil crossed, a series of peculiar characteristics and a particular severity of the seismic actions that stress the structures on the surface. In detail, the characteristics of "near fault" earthquakes are the following: • Forward-directivity consisting in the fact that, if the failure front of the fault propagates towards the site