2011年東北地方太平洋沖地震における戸建免震住宅の免震層変形と足柄平野の地盤震動特性との関係

摘要

2011年東北地方太平洋沖地震における戸建免震住宅の免震層変形と足柄平野の地盤震動特性との関係について検討した。その結果、浅部地盤の固有周期と免震層変形に良い相関は見られず、常時微動観測から推測される深部地盤の1次固有周期と良い相関があった。%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.