The Non-smooth Dynamics of Multiple Leaf Masonry Walls of the Arquata Del Tronto Fortress

The progressive damage of the multiple leaf masonry walls of the Arquata del Tronto medieval fortress, inside the epicentral zone of the last Centre Italy earthquakes of August and October 2016, has been investigated by means of the Non-Smooth Contact Dynamics method (NSCD). According to this model, the masonry structure has been modelled as a system of rigid blocks, and since the contacts between blocks are governed by the Signorini’s impenetrability condition and by dry-friction Coulomb’s law, the building exhibits discontinuous dynamics. The NSCD method has proved to be a powerful tool for investigating the dynamics induced by ground seismic accelerations. Indeed, the numerical results have given a deep insight into the seismic vulnerability of this damaged medieval fortress, confirming several possible failure mechanisms.