Post-tensioned CLT rocking walls with sliding keys on inclined deflecting-cantilevers device

Abstract Previously, the authors proposed a novel Sliding Keys on Inclined Deflecting-cantilevers (SKID) device for application within post-tensioned (PT) frames. The device was designed to provide hysteretic damping without an activation threshold, characterised by a triangular-shaped force-displacement hysteretic curve, thereby offering greater design flexibility when implemented in PT frames. In this paper, the SKID device is integrated into post-tensioned cross-laminated timber (CLT) rocking walls as a supplemental damping device, resulting in a self-centring seismic force-resisting system (referred to as PTCLT-SKID rocking walls) with enhanced energy dissipation. The behaviour of the PTCLT-SKID rocking walls is demonstrated using a six-storey prototype building. Static cyclic analysis in OpenSeesPy shows that the system exhibits a dual-triangular, flag-shaped hysteretic force-displacement response. Nonlinear response history analyses, conducted using 44 hazard-consistent ground motions, highlight the system’s global response with negligible residual deformations. Responses of critical components, including the hysteresis of the SKID device and the strain of CLT fibers at the rocking pivots, are also investigated. Since CLT fiber strains at rocking pivots are a key damage indicator, this paper establishes a mathematical relationship between CLT strain and the roof drift ratio to support performance-based seismic design of PTCLT-SKID rocking walls.