Seismic Response of Rocking Precast Concrete Cladding System in a Full-Scale Three-Storey Building

Precast concrete cladding systems are not only vulnerable to seismic damage but also pose a life-safety hazard due to the potential for panel detachment and falling during earthquakes. However, research assessing seismic response of the cladding systems installed on full-scale buildings under dynamic loading is limited. To address this gap, an experimental programme was undertaken as part of the RObust BUilding SysTem (ROBUST) project. In this study, rocking cladding panels were installed on the upper two storeys of a full-scale, three-storey steel frame building specimen. The building was subjected to unidirectional and bidirectional horizontal ground motions, inducing peak inter-storey drift ratios of up to 1.71% and peak floor accelerations of up to 0.95 g at the storeys where the cladding panels were installed. This paper presents the experimental findings on the seismic response of the rocking cladding system, including peak rocking displacements and component acceleration amplification factors. Physical damage observations are categorised by severity and correlated with inter-storey drift ratios. Damage to the sealant was first observed at a peak inter-storey drift ratio of 0.51% in one of the cladding systems, while the remaining eleven cladding systems sustained drift levels up to 1% without any damage. Additionally, vibration modes and corresponding frequencies are identified. The results demonstrate that the rocking cladding system effectively accommodated the imposed seismic demands without severe damage or collapse, highlighting the rocking mechanism as a low-damage solution for precast concrete cladding systems.