Effectiveness of geotechnical seismic isolation for post-tensioned rocking piers

Post-tensioned (PT) rocking piers have received considerable attention as an advantageous solution for seismic resilient structures. Their self-centering capacity, the advan-tages related to the column-uplifting mechanisms, and the possibility of being combined with energy dissipation devices largely contributed to this increasing attention. Simultaneously, Geotechnical Seismic Isolation (GSI) has emerged as a technique to reduce the seismic vulner-ability of structures. The GSI a technique is based on design of a suitable interface between the foundation of the structure and the surrounding terrain. Such an interface can work as seismic isolation and energy dissipation mechanism. This research investigates the use of GSI for PT rocking piers equipped with external energy dissipation devices. The main focus of the investigation is the comparative assessment of the effectiveness of external dissipators and GSI to ascertain if the two protection mechanisms can synergize and collaboratively enhance the safety of the structure. The investigation employs numerical simulations through the direct integration of the equation of motion of the studied system. The outcomes of the para-metric analysis are presented in gain maps that illustrate the effectiveness of the coupling within a designated parameter plane. Preliminary results show that GSI could be effective in combination with external dampers in reducing the seismic effects on rocking piers.