Effects of the In-Plane/Out-of-Plane Interaction in URM Infills on the Seismic Performance of RC Buildings Designed to Eurocodes

Incremental dynamic analyses are performed on 48 infilled reinforced concrete buildings different for infill typology, number of storeys and design peak ground acceleration (PGA). A modelling strategy accounting for infills’ interacting in-plane (IP) and out-of-plane (OOP) responses is implemented. The seismic displacement demand on buildings may be highly underestimated if the IP/OOP interaction is neglected. The PGA at the first OOP collapse is evaluated. Two-leaf infills may be not safe with respect to the OOP collapse. The OOP behaviour factor (q) of infills accounting for the IP/OOP interaction effects is determined. It is suggested assuming q equal to the unit.