Seismic behaviour of mixed RC-URM wall structures: comparison between numerical results and experimental evidence

Although mixed reinforced concrete (RC) - unreinforced masonry (URM) wall structures are often used, experimental and numerical studies on their seismic behaviour are scarce. Previous studies pointed out that the obtained results from numerical simulations are strongly dependant on the modelling assumptions. Two quasi-static cyclic tests on mixed RC-URM wall structures were recently completed at EPFL: the tests were carried out using a novel set up capable of measuring the reaction forces (axial force, bending moment, shear force) at the base of the URM wall and allowing to back-calculate the reaction forces at the base of the RC wall. A further objective of the research programme is to provide general guidelines for the analysis of mixed RC-URM wall structures using different numerical approaches. In the paper, a micro-modelling / shell element approach was adopted to study the seismic behaviour of such mixed structures; the numerical results – in terms of reaction forces, inter-storey drifts and deformed shapes – are discussed and compared against the obtained experimental results.