Seismic retrofit of multi-story structures with KDamper-based vibration control systems considering soil–structure-interaction

Abstract

This study introduces a novel retrofit seismic protection strategy utilizing the internal mechanism of the Extended KDamper (IEKD) to address the limitations of conventional mass-related vibration control systems and enhance the seismic resilience of multi-story structures. The IEKD is implemented between the foundation and the first floor, offering a lightweight alternative to classical approaches, such as the Tuned Mass Damper (TMD), which rely on large auxiliary masses and are highly sensitive to soil–structure-interaction (SSI) effects. Unlike traditional systems, the IEKD design explicitly accounts for SSI, ensuring robust performance across various soil conditions. A systematic optimization framework is developed to determine the IEKD parameters for different soil types, seismic inputs, and structural configurations. Ground motion excitation is represented by EC8-compatible artificial accelerograms. The performance of the IEKD is subsequently assessed with real earthquake records modified to reflect diverse soil conditions. A case study of a benchmark ten-story structure highlights the superior performance of the IEKD in reducing structural accelerations and floor drifts compared to conventional TMD systems, despite utilizing significantly lower additional mass (20 times lower). The findings of this study demonstrate that the IEKD is both effective and practical, offering a lightweight solution for seismic upgrade and establishing it as a compelling alternative for retrofitting existing multi-story structures.