Dynamic response of a non-structural component with three supports in multi-directional earthquakes

Multiply-supported non-structural components (NSCs) can be vulnerable under strong multi-directional earthquake excitations. To date, this topic has not been explored much, not to mention considered in design provisions. Seismic analyses of NSCs with multiple attachments were mostly performed numerically and with simplified assumptions. Experimental investigation is scarce. The goal of this study is to describe the seismic behaviour of a multi-supported NSC under multi-directional excitations through experiments. Large-scale testing was implemented to study the development of acceleration from the ground to the NSC, which would otherwise be too small to detect in a small-scale setup. The influence of the vertical component of the excitation on the response of the NSC is displayed. The interaction between the primary structure and the NSC was showcased through its influence on the response of both the primary structure and the NSC. For the first time, seismic response of a multi-supported NSC is expressed using physical experiments, thus accounting for its interaction with the main structure. The seismic demand for multiply-supported NSCs specified in current design provisions is also evaluated.