Discrete-element analysis of floor influence on seismic response of masonry structures

Traditional masonry buildings are highly vulnerable to earthquake loading and their dynamic response is stronglyinfluenced by the in-plane deformability of the timber floors and the quality of the wall-to-floor connections.Understanding the behaviour of timber floors and roofs and their interaction with masonry walls is thereforefundamental for the protection of historical buildings. In a previous research project, different timber-baseddry-connected strengthening solutions for timber floors were tested under in-plane loading. The experimental resultsshowed a significant increase in shear strength and stiffness. In the current study, the discrete-element method (DEM)was used to model a simple masonry structure and evaluate the effectiveness of strengthening solutions to avoidtriggering first-mode mechanisms, namely out-of-plane collapse of masonry walls. The structure was stressed byseismic ground accelerations. The unreinforced and reinforced floors were modelled with non-linear springs thatreproduced their experimental hysteretic response. Parametric analyses were performed, changing the geometryof the structure and the masonry wall thickness. The comparison highlighted the effectiveness of the proposedwood-based strengthening solutions for reducing out-of-plane displacements of masonry walls, potentially matchingthe performance of rigid floors.