Numerical Study on Seismic Retrofit of URM Walls Using Timber Panels

Unreinforced masonry (URM) buildings are characterized by high vulnerability to lateral loading, which is often manifested when an earthquake occurs. The present study investigates the effectiveness of a timber-based retrofit solution aimed at reducing the seismic vulnerabil-ity of existing URM structures. The retrofit technique consists of connecting timber-based panels, to the interior surface of the walls of a building using mechanical or adhesive point-to-point connections. The application of those panels allows to considerably increase both the in-plane and the out-of-plane capacity of the URM walls, while preserving the original exter-nal facades of the retrofitted building. This solution resulted to be relatively fast and easy to install and the reversible nature of the system allows to reduce the impact of the retrofit inter-vention. In this work the in-plane behaviour of the retrofitted walls was investigated numerically, building on previous preliminary analyses and in the lights of the results of experimental evi-dence collected by the authors’ research team. The effectiveness of this retrofit solution was analysed on several masonry types, considering different masonry properties and geometries. The influence of various parameters (such as masonry-to panel connection typology, connect-ors number and position) on the increase of lateral capacity of the retrofitted walls was stud-ied by means of a series of non-linear quasi-static simulations.