Structural Dynamics Approaches for Mitigating Seismic Risk of Italian Existing Buildings

The research project aims to gain insights into the non-smooth contact dynamics of existing masonry structures, which represent the major part of the historical architectural heritage of Italian cities and are sensibly vulnerable with respect to moderate-large earthquakes, that relatively often occur in the Italian territory, characterised by high seismicity rate. Additionally, masonry constructions should not be demolished and reconstructed due to their architectural and historical values, according to ICOMOS and ISCARSAH guidelines [1]. In the last decades, several numerical methods have been proposed in the inherent literature in order to faithfully grasp the actual behaviour of these structures, and, more importantly, to define ad hoc seismic retrofit interventions. Despite the numerous different approaches suggested, the debate within the scientific community is still alive and does not converge on a unique structural model. With the aim of providing a novel understanding of the complex mechanics of masonry structures, we enhance some discrete element methods addressed by the inherent literature, also giving raising further issues into non-smooth contact dynamics of rigid masonry blocks separated by mortar joints. In detail, more refined models are uploaded to account for some dissipative mechanism, e.g. the rocking phenomena and the contact friction between rigid blocks and several parametric analyses are implemented, in order to provide a comprehensive view on the competition of the above-mentioned effects on the strong nonlinear dynamics of masonry panels. These results can be helpful for defining novel smart engineering interfaces that replace the mortar joints at specific parts of the structures, thus improving the seismic behaviour of the whole complex. Therefore, it is believed that this research can respond to the need to adapt the existing architectural heritage in high seismicity areas like Italy with minimally invasive interventions that do not alter the building’s structure, thus preserving its historical, artistic and architectural value.