The dynamic behaviour and the seismic vulnerability of the ancient civic tower of Amatrice, dramatically damaged by the last shocks sequence of 2016 that occurred in Central Italy, have been studied in this paper by means of advanced 3D numerical analyses with the Discrete Element Method (DEM). Thus, a discontinuous approach has been used to assess the dynamic properties and the vulnerability of the masonry structure, through large deformations regulated by the Signorini’s law, concerning the impenetrability between the rigid bodies, and by the Coulomb’s law, regarding the dry-friction model. Afterward, different values have been assigned to the friction coefficient of the models and real seismic shocks have been applied in the nonlinear analyses. The major purpose of this study is to highlight that relevant data on the real structural behaviour of historical masonry can be provided through advanced numerical analyses. The comparison between the results of the numerical simulation and the survey of the existing crack pattern of the bell tower permitted to validate the approach used. Finally, from the results and conclusions of this case study, it is possible to affirm that the used methodology can be applied to a wide variety of historical masonry structure in Europe.

Masonry minarets constitute an important component of Islamic architectural heritage. Beyond their religious function, they stand as social and cultural landmarks reflecting the diversity of architectural styles and building techniques of the regions in which they are located. Historical minarets have demonstrated remarkable resilience against environmental degradation and aging; however, in seismically active regions, earthquakes pose a major threat to their integrity. Due to their slender geometry and material characteristics, these structures are particularly vulnerable to seismic effects. Many historical records document that minarets have suffered severe damage and collapse during earthquakes. This study presents a state-of-the-art review of seismic vulnerability assessments of masonry minarets. It concentrates on Southwest Asia and the Mediterranean, regions that are characterized by high seismic risk and a rich inventory of this structural typology. Currently employed approaches to the seismic analysis of minarets typically require substantial computational resources and expertise. Recognizing the need for rapid and accessible methodologies in place of them, this study proposes a Kinematic Limit Analysis framework that is suitable for fast vulnerability assessment of large-scale building stocks. This allows for the most critical structures to be identified for further scrutiny using more sophisticated approaches.

Many existing reinforced concrete buildings in Southern Europe were built (and hence designed) before the introduction of displacement based design in national seismic codes. They are obviously highly vulnerable to seismic actions. In such a situation, simplified methodologies for the seismic assessment and retrofitting of existing structures are required. In this study, a displacement based procedure using non-linear static analyses is applied to a four-story existing RC frame. The aim is to obtain an estimation of its overall structural inadequacy as well as the effectiveness of a specific retrofitting intervention by means of GFRP laminates and RC jacketing. Accurate numerical models are developed within a displacement based approach to reproduce the seismic response of the RC frame in the original configuration and after strengthening.