Seismic Retrofit of a URM Building with Timber-Based Coating: A Numeric Study

This work investigates the effectiveness of timber-based coatings in improving the seismic behaviour of unreinforced masonry buildings. The present study focuses on the seismic behaviour of a full-scale building retrofitted with the aforementioned technique and investigated numerically. The retrofit strategy consists of connecting timberbased panels to the surface of the building walls using mechanical or adhesive point-to-point connections spread over the wall surface. The retrofit allows a considerable increase in both the in-plane and the out-of-plane capacity of the masonry walls. The timber panels can be fixed on the internal or external side of the building walls. Membranes, insulation layers and finishing layers can be added to the retrofit to ensure the durability of the timber products and improve the thermo-physical performance of the building. A detailed modelling approach was developed, building on previous analyses performed by the authors on retrofitted masonry piers and walls with openings, to assess both the global and the local behaviour of a retrofitted masonry building and to provide data that could be used as reference for the calibration of less refined, yet computationally more efficient, macro-element models. Various retrofit configurations were analysed, considering the timber panels applied to the entire perimeter walls of the building or to selected elements (e.g., retrofit applied to masonry piers alone or both piers and spandrels) and involving different geometries influenced by the maximum panel transportable size. The effectiveness of the retrofit configurations was evaluated in terms of increased lateral load and displacement capacity through non-linear simulations.