PSI - Issue 78

Franco Braga et al. / Procedia Structural Integrity 78 (2026) 2176–2183

2183

combinations using code-prescribed actions (NTC08) and the recorded actions (AMTS 24.08.2016). For illustrative purposes, the interstory drift has been reported for three columns (two corner columns [P1 and P17] and one central column [P10]), highlighting the increase in displacement demands compared to the NTC08 requirements, to which the building was subjected due to the severity of the earthquake on August 24, 2016.

Fig. 9. Interstorey Drift for columns P1 – 10 - 17 The results presented show a high interstory drift demand, with increases exceeding 20% for the first spans when comparing the design earthquake (NTC08) with the recorded earthquake (AMTS). 6. Conclusions The study of the recordings obtained on the night of August 24, 2016, from the accelerometric stations AMT and AMTS made it possible to highlight the peculiar characteristics of the event and to classify it among the near-fault earthquakes, which exhibit a higher degree of severity compared to the far-fault earthquakes currently codified by Italian and European seismic design standards. Subsequently, structural analyses were carried out on the twin reinforced concrete buildings located a few meters from the AMTS accelerometric station. These buildings, designed in 1973 according to the seismic code in force at the time (Law 1684/62) and which collapsed during the event of August 24, 2016, confirmed that the recorded earthquake produced stresses significantly more severe than those prescribed by the standards in force at the time (NTC 2008), in terms of both strength demand and displacement demand. The findings of this study therefore highlight the need to update the European and Italian seismic codes, which currently make no reference to the distance between the expected earthquake source and the site of the structure under examination, effectively disregarding near-fault seismic events. References Somerville, P. G., Smith, N. F., Graves, R. W., & Abrahamson, N. A. (1997). Modification of empirical strong ground motion attenuation relations to include the amplitude and duration effects of rupture directivity. Seismological research letters, 68(1), 199-222. Braya&Rodriguez Marek, 2004 “Characterization of forward-directivity ground motions in the near-fault region”, Soil Dynamics and Earthquake Engineering,24: 815-828 Ghahari et al., 2010 “Study on elastic response of structures to near-fault ground motions through record decomposition” Memarpour M.M., GhodratiAmiri G., Razeghi H., Akbarzadeh M., Tajik Davoudi A., 2016 “Characteristics of Horizontal and Vertical Near Field Ground Motions and Investigation of Their Effects on the Dunamic Response of Bridges”, Journal of Rehabilitation in Civil Engineering, 4-(2): 1-24 Uniform Building Code 1997 (ICBO 1997) ATC-40 (ATC,1996) “Seismic Evaluation and Retrofit of Concrete Buildings” ASCE/SEI 7-10 (ASCE, 2010) “Minimum Design Loads for Buildings and Other Structures” New Zealand NZS 1170 – part 5 and commentary (NZS, 2004): Near-fault factor (NZS, 2004, Clause 3.1.6, C3.1.6) UNI EN 1998-1 “Eurocode 8 – Design of structures for earthquake resistance” NTC2008 D.M. 01.14.2008 – “Norme tecniche per le costruzioni ” NTC2018 D.M. 01.17.2018 – “Aggiornamento delle Norme tecniche per le costruzioni”