Performance of Seismic Protection Technologies during the 2011 Tohoku‐Oki Earthquake

Many buildings in the Tohoku and Kanto area were strongly shaken during the Tohoku‐oki earthquake on 11 March 2011. Soon after the earthquake, the Japan Society of Seismic Isolation (JSSI) established committees to investigate the performance of structures where modern seismic protection methods were used. Since response‐control technologies are relatively new, few systems had been validated with actual earthquakes. Generally, the various buildings performed well, and there were no failures of superstructures of base‐isolated or supplementally damped buildings. Failures of numerous expansion joints and lead dampers in base‐isolated buildings are described. Acceleration records of both base‐isolated and supplementally damped buildings are analyzed and their seismic performance characteristics are discussed.