Development of Seismic Isolation Fail-Safe Structure Against Huge Earthquakes

Abstract

The seismic isolation devices with damping performance deteriorates their damping performance when they are repeatedly deformed by long-period earthquake motions. Therefore, there are concerns that the superstructure collide with the retaining wall at the seismic isolation layer may or damage the seismic isolation devices in the event of a huge earthquake that exceeds the design assumption. Increasing the damping of seismic isolation devices is an effective way to cope with huge earthquakes, but excessive damping leads to an increase in acceleration of the superstructure, resulting in a reduces seismic isolation performance. To address this problem, we developed a fail-safe braking device that acts only in the event of a huge earthquake and prevents excessive displacement of the superstructure. Moreover, the effectiveness of the device was confirmed by seismic response analysis.