We investigated structural characteristics of the base isolated buildings designed by the time history response analysis. The investigation period is from November 2014 to March 2017, it is just before long-period ground motion is legally required. Main investigation items are type of input ground motion, combination of base isolation devices, response characteristics and energy absorption amount of the base isolated buildings. As a result of the survey, in many cases, the large deformation’s natural period is about 5 seconds, the yield shear strength coefficient of the base-isolation story was about 2%, and oil dampers were used in combination.
