Analysis and Seismic Retrofit of Historical Masonry Buildings under Earthquake Loading: a Case Study

Historical masonry buildings generally show a high level of vulnerability to seismic actions, due to different reasons, as the lack of effective connections between structural elements, the absence of rigid planes, the dimensions and specific arrangements of masonry panels and the mechanical properties of masonry itself. The need of retrofitting to achieve adequate levels of safety on the basis of the more recent design approaches guarantying at the same time the architectural preservation is a difficult task. In this study a historical masonry structure, located in the South of Italy (Lecce), has been analysed in terms of vulnerability evaluation to seismic actions and possible retrofitting solutions. The case study presented aims to contribute to the complex problems of seismic retrofitting approach of masonry structures. The degree of seismic vulnerability of the structure under examination was evaluated on the basis of different numerical analyses, once the structural modelling was defined. A finite element method was adopted for a linear dynamic 3D analysis and an non-linear 3D pushover analysis. In particular the push-over approach allowed to evaluate the non linear capacity of the structure, the obtained results were compared with codes provisions as regard the “q” factor indications. The analysis of more suitable and opportune seismic retrofit actions have been performed with the support of Italian CNR recommendations, and on the basis of some experimental results. In particular strengthening techniques using FRP materials have been proposed.