The objective of this thesis is to develop a dual-functional approach to effectively mitigate the earthquake induced vibrations of low- or mid-rise buildings, and at the same time to efficiently harvest utility-scale energy by using an optimally configured multi-resonant electromagnetic shunt in base isolation. In this research, two multi-resonant shunt configurations, parallel and series, were proposed and optimized based on the H2 criteria when the base isolation system is subjected to ground acceleration excitations. The performance of the proposed multi-resonant electromagnetic shunt was compared with traditional multiple tuned mass dampers (TMDs) applied to the base isolation system. It shows that, for multiple TMDs and multi-resonant electromagnetic shunt dampers with 5% total stiffness ratio, the parallel shunt electromagnetic shunt can achieve the best vibration mitigation performance among other types of multi-resonant dampers, including parallel TMDs, series TMDs and the series electromagnetic shunt damper. Case study of a base-isolated structure was analyzed to investigate the effectiveness of the proposed multi-resonant electromagnetic shunt. It shows that both multi-mode shunt circuits outperform single mode shunt circuit by suppressing the primary and the second vibration modes simultaneously. Comparatively, the parallel shunt circuit is more effective in vibration mitigation and energy harvesting, and is also more robust in parameter mistuning than the series shunt circuit. The time history response analysis shows that, under the recorded Northridge earthquake, the instant peak power and total average power capable to be harvested by the multi-resonant shunt can reach up to 1.18 MW and 203.37KW, respectively. This thesis further experimentally validated the effectiveness of the multi-resonant electromagnetic shunt on a scaled-down base-isolated building. The impact hammer test shows that the multi-resonant electromagnetic shunt can achieve enhanced vibration suppression by reducing the first resonant peak by 27.50dB and the second resonant peak by 22.57dB regarding the primary structure acceleration. The shake table test shows that under scaled Kobe and Northridge earthquake signals, the electromagnetic shunt can effectively reduce the vibration resonant peak value by 38.92% and 66.61%, respectively. The voltage simultaneously generated in the multi-mode shunt circuit was also obtained, which demonstrated the dual functions of the multi-resonant electromagnetic shunt in base isolation. / Master of Science / This thesis investigated multi-resonant electromagnetic shunt with application to base isolation for dual-functional vibration damping and energy harvesting. Two multi-mode shunt circuit configurations, namely in parallel and in series, were proposed and optimized based on the <i>H</i>₂ criteria, with physical meaning to minimize the RMS relative displacement for the concern of building safety subjected to broad bandwidth ground acceleration excitations. The performance of the proposed multi-resonant electromagnetic shunt was compared with traditional multiple tuned mass dampers applied to the base isolation system. It shows that, for multiple TMDs and multiresonant electromagnetic shunt dampers with 5% total stiffness ratio, the parallel shunt electromagnetic shunt can achieve the best vibration mitigation performance among other types of multi-resonant dampers, including parallel TMDs, series TMDs and the series electromagnetic shunt damper. Case study of a base-isolated structure is analyzed in both the frequency and the time domain to investigate the effectiveness of the multi-mode electromagnetic shunt resonances. It is found that both multi-mode resonant shunt circuits outperform single mode resonant shunt circuit by suppressing the primary and the second vibration modes simultaneously. In addition, under the same stiffness ratio, parallel shunt circuit is more effective in energy harvesting and vibration suppression. And parallel shunt circuit is also more robust to parameter mistuning than series shunt circuit. This thesis further experimentally validated the effectiveness of the multimode electromagnetic resonances for vibration damping and energy harvesting using recorded earthquake signals on a scaled-down building.