Seismic rocking simulation of unreinforced masonry parapets and façades using the discrete element method

When subjected to high-intensity out-of-plane seismic loading that results in the threshold value of static stability being exceeded, unreinforced masonry parapets and façades form mechanisms exhibit rigid body rocking motion before collapse. The discrete element method was used perform simulations which were compared experimental observations analytical models obtain relationships enable stiffness proportional Rayleigh damping parameter (β) be estimated from coefficient restitution. performance using incremental dynamic analysis, similar observed between models, confirming validity developed expressions β. gap size generated after failure façade return wall parametrized outcome revealed hazardous situation arises when connectivity uncollapsed adjacent walls is damaged during an earthquake. Pulse-like accelerations, generally associated with near-fault earthquakes, caused collapse at substantially lower accelerations earthquakes oscillations evenly distributed time. It concluded assessing vulnerability a located near fault, capacity equal free-standing block should used, validating assumption made some assessment guidelines not considering effect capacity. For far fault range represent site conditions needs included any assessment.