Using DEM to Investigate Boundary Conditions for Rocking URM Facades Subjected to Earthquake Motion

Façade overturning is a frequently observed collapse mechanism occurring in unreinforced masonry (URM) buildings during high-intensity, earthquake-induced shaking. Following complete separation from a building, the rocking motion of a URM façade and the associated impact against the return walls are the factors that continue to contribute to the façade out-of-plane capacity. Seismic vulnerability studies of URM façades have historically neglected the interaction between building earthquake response and the rocking response of the façade, whereas in the study reported herein this interaction was analyzed using the discrete element modeling (DEM) approach, resulting in a façade out-of-plane capacity reduction. The increment in the dynamic rocking capacity caused by the frictional connection between the URM façade and the building was also analyzed and is reported.