In the North-East part of The Netherlands, induced seismicity due to gas extraction is affecting a local building stock consisting mainly of unreinforced masonry (URM) houses not designed for earthquake resistance. Experimental and numerical studies conducted at EUCENTRE, Pavia (Italy), have demonstrated that buildings with URM cavity-walls structural systems are among the most vulnerable existing Dutch construction typologies. A light and reversible retrofit system made of timber frames and oriented-strands boards was then designed and tested to increase the in-plane and out-of-plane capacities of masonry piers and to enhance their connections with the floor diaphragms. The development of modelling approaches able to simulate the influence of the retrofit system is of fundamental importance for future applications to real-case existing buildings and for vulnerability studies on different building stocks. Based on two quasi-static in-plane shear-compression tests on two full-scale masonry piers, one in bare and one in retrofitted configuration, a specific macroelement was calibrated to simulate the bare pier lateral response and the effects of the retrofit on the in-plane flexural and shear capacities. This paper discusses the adopted modelling strategies and the comparison between numerical and experimental results
