Test-Based Assessment of the Seismic Response of Bracing Systems for Concealed Grid Suspended Ceilings

Despite not directly contributing to a structure’s load-bearing capacity, nonstructural elements like partitions, cladding, ceilings, floor finishes, and facades play a pivotal role in the overall building design and occupant safety. Their susceptibility to damage during seismic events, however, can lead to substantial economic losses, business interruptions, and potential risks to occupants. Focusing on concealed grid suspended ceiling systems, this study focuses on enhancing their seismic resilience introducing and experimentally evaluating two innovative bracing systems (Typology N and Typology W) that utilize steel members, already used in non-seismic application, as braces. Unlike prior research using shake tables, this study employs a specially designed set-up on a universal testing machine, offering a cost-effective and efficient approach for cyclic testing and considering the spatial variability of seismic loads. As a complementary task, component-level tests were conducted on the compressed strut to extend the results for suspended ceiling systems having suspension height up to 2 meters. The results show that Typology N performs better than Typology W, with 1.7 times greater resistance and 2.5 times greater stiffness on average, demonstrating the importance of considering different directions of horizontal seismic loading in the performance assessment. The study provides valuable insights, including design resistance values and a step-by-step procedure for determining the maximum ceiling area that a single bracing system can cover, aiding in optimizing bracing system selection and mitigating seismic vulnerability in concealed grid suspended ceilings for seismic-prone regions.