Small‐Scale Shaking Table Tests of an Elastic Single‐Degree‐of‐Freedom Frame Supported on a Base‐Isolated Platform Through a Rocking Column Mechanism

This study presents small‐scale shaking table tests of an elastic single‐degree‐of‐freedom frame supported on a base‐isolated platform through a rocking column mechanism. Two specimens were designed and tested: a free rocking isolation system (FRIS), and a controlled rocking isolation system (CRIS) incorporating Ni‐Ti shape memory alloy (SMA) wires, shear keys, out‐of‐plane braces, and restraining blocks were employed to mitigate sliding, suppress out‐of‐plane responses, and slab rotation, respectively. Quasi‐static cyclic tests were conducted to characterise the mechanical properties of the SMA wires. Free rocking tests and white‐noise excitations were then performed to identify the coefficient of restitution and structural frequency parameters. System‐level push‐pull tests were carried out. Shaking table tests were conducted using analytical pulse‐type accelerations, with each test repeated twice to evaluate experimental repeatability. The results indicate that both specimens exhibit excellent experimental repeatability. Neither the FRIS nor the CRIS specimen experienced damage or residual deformation after being subjected to a total of ninety‐four excitations. The experimental results were also compared with the analytical model and finite element model proposed in our prior work. The comparison results demonstrate that both models accurately capture the cumulative distribution functions of experimental peak rocking rotations and the elastic response of the superstructure. Rocking spectra were established using the validated analytical model, which demonstrates that the supplemental devices improve collapse resistance for rocking isolation structures with small‐size columns or under long‐duration pulse‐like ground motions, whereas their effectiveness reduces for large‐size columns or under high‐frequency ground excitations.