Shake-table tests of innovative drift sensitive non-structural elements in a low-damage structural system

Post-earthquake damage reports have continuously highlighted the significant vulnerability of non-structural elements to seismic events. Non-structural damage has severe impact in the building recovery, increasing the socio- economic losses even for low intensity events. In the last few years, research efforts have focused on the development of innovative non-structural solutions, to be combined with damage-resistant structural skeletons in order to obtain an overall high-performance building. As part of a European Union (EU)-funded project, the effectiveness of such integrated skeleton&envelope low-damage system in reducing the earthquake related losses has been investigated. Tri-dimensional shake table tests on a 1:2 scaled timber-concrete low-damage structural skeleton, “dressed” by different innovative non-structural elements (glass/concrete facades, gypsum/masonry partitions), have been performed at the Laboratório Nacional de Engenharia Civil (LNEC) in Lisbon, Portugal. The shake table tests were carried out at increasing seismic intensities to investigate the structural and non-structural performance up to a higher-than Collapse Prevention Limit State according to the Italian Code (975 years return period). This paper focuses on the dynamic behaviour of non-structural elements with detailed discussion on construction detailing, seismic demand and performance of the innovative solutions. The high performance of non- structural elements proved the potential of the details introduced in the partitions/facades. Minimal or no damage was observed up to the end of the overall testing sequence, that is at moderate-high inter-storey drift ratios (more than 1.00%) typically expected to cause severe damage to traditional non-structural partitions/infills/facades.