Authors suggest a base-insulation system using a permanent magnet and a displacement control material made of a compound geomaterial for reducing seismic response of small buildings. The electromagnetic theory provided a method for calculating magnetic force and revealed its important properties such as nonlinearity and negative stiffness. A shaking table test and a finite element analysis demonstrated the response reduction by the magnetically levitated foundation. The analytical study clarified that the restoring force of the displacement control material canceled the magnetic negative stiffness and governed the impedance of the foundation for the seismic response.
