Improved seismic resilience through controlled multiple-rocking for columns in the Parthenon

Multi-drum rocking columns (MDRC) with dry joints can rock and self-center under gravity, but negative post-rocking stiffness can produce larger displacements during strong earthquakes. This study proposes a simple stiffening system that combines a spring and a prestressed cable to tune post-rocking stiffness and pretension. Theoretical formulae are derived for the initial stiffness and the post-rocking stiffness, then validated with experiments and numerical simulations. Both free-rocking and controlled MDRC configurations are examined to compare dynamic performance. Results show that the controlled system reduces peak displacement and improves self-centering properties. Parametric analyses indicate that higher spring stiffness and greater initial pretension limit multi-drum rocking and improve self-centering. Additionally, this study introduces dimensionless measure for stiffness and pretension to provide practical selection guidance which improves seismic resistance, while keeping all devices concealed to preserve architectural appearance.