Effect of Retaining Wall Stiffness on the Integrity of Structures and Equipment of Base-Isolated Structures During Retaining Wall Collisions

Abstract

Seismic isolation structures, using devices such as laminated rubber bearing, shift the natural period of the structure to avoid resonance phenomena and significantly reduce seismic forces by incorporating damping properties. This approach has been considered not only for general buildings, but also for critical infrastructure such as nuclear power plants. However, in recent years, earthquakes exceeding the maximum seismic events designed for nuclear power plants have been observed on several occasions. Therefore, it is crucial to assess the safety of structures against beyond design ground motions. In this study, a nonlinear seismic response was performed to investigate the impact of retaining wall collisions on the isolation building and internal equipment under large earthquake scenarios. The parameters considered include the seismic ground motion, amplification factor, clearance amount, collision restitution stiffness, etc. As a result of this study, we confirmed that not only the damage to the isolation building but also the damage to the internal equipment should be considered for the seismic risk analysis with collision.