Seismically isolated buildings are required to secure a safety margin against extreme ground motion. A possible countermeasure is to install a fail-safe mechanism in the seismic isolation layer. In this study, the fail-safe mechanism using bent steel plates is proposed, and the mechanical properties of the fail-safe mechanism are investigated by shear loading test and finite element analysis. Furthermore, the hysteresis model of the fail-safe mechanism is proposed, and the influence of hysteresis characteristics of the fail-safe mechanism on the seismic response of seismically isolated buildings is investigated by time history response analysis.
