The authors have investigated the relationship between deformations of the seismic-isolated layer of houses and ground vibration properties in the Ashigara valley during the 2011 Tohoku earthquake. As a result, deformations of the seismic-isolated layer of houses are greatly affected by both the surrounding geography, and the structure of deep layers of the ground rather than the surface layers.
The authors have also verified how seismic-isolated houses resonate with long-period ground motion based on full scale shaking table tests, and indicated that ground vibration properties could be markedly different locally in the Ashigara valley.
