"This project aims at investigating the structural assessment and retrofitting of ancient masonry buildings (AMB), focussing on the computational modelling of existing masonry structures. The main goal of the proposed work is the development of novel numerical modelling tools. The training activity is therefore focused mainly towards this end. A multidisciplinary scientific training, combining structural modelling with advanced computing concepts, will dramatically enhance the applicant’s expertise in the field. The proposed numerical modelling of AMB is based on the use of both an effective constitutive model for the masonry, assumed as a composite material under monotonic and cyclic loads, and a suitable kinematic approach for discretizing complex geometrical configurations. A novel dynamic masonry element will be developed by considering a multi-scale approach, thanks to the inherent advantages of the method with respect to the micromodel and macromodel approaches which are currently the most used. By coupling macroscopic and microscopic models, the combined advantages of simplicity and efficiency of the macroscopic models as well as accuracy of the microscopic models can be exploited. Furthermore, the multi-scale approach allows the determination of the mechanical properties of masonry using only slightly invasive in-situ experimental tests, which is of paramount importance for buildings of historical value. The modelling of multi-leaf masonry walls will be addressed in this project, where normal masonry structures involving single-leaf walls can be considered as a particular case. The developed model will be implemented within a parallel processing computational environment, so as to maximise computational efficiency in modelling real AMB structures. Finally, the model will be used to investigate the effectiveness of a number of strengthening techniques for multi-leaf masonry walls as well as their contribution to structural behaviour of strengthened panels."