Out-of-Plane Behavior of Load-Bearing Reinforced Masonry Shear Walls

The increase in the number of deliberate and accidental explosion events over the past two decades has necessitated evaluating the performance of blast-vulnerable structural components and developing subsequent risk mitigation strategies. In this context, several studies have focused on the out-of-plane behavior of either unreinforced masonry walls or non-load bearing reinforced masonry shear walls (RMSWs). However, to date, few studies have focused on the interaction between the axial load and the out-of-plane (e.g., when shear walls are subjected to blast loads) demands on such walls. As such, the current study focuses on evaluating the out-of-plane behavior of seismically-detailed RMSWs with different design parameters. In this respect, the experimental results of seven scaled RMSWs, with different in-plane ductility seismic classifications and axial stress levels, subjected to out-of-plane loading are first presented. Such results include the wall damage sequence, load-displacement response, stiffness degradation, and energy dissipation. Subsequently, the resistance function predictions based on the Unified Facilities Criteria guidelines are compared with the experimental results. Furthermore, an experimentally validated analytical resistance function is developed considering the postpeak behavior of RMSWs, including second-order effects. The current study extends the database of experimental and analytical results pertaining to load-bearing RMSWs, to facilitate the development of relevant provisions within the next generation of blast design standards.