A new interpretation of large amplitude earthquake acceleration from non-linear local soil-structure interaction

• A new interpretation of large earthquake accelerations is provided.
• Non-linear interaction between an embedded building and its surrounding soil is a key.
• A bi-linear restoring-force characteristic with a gap-slip process is used for analysis.
• Ricker wavelet and a continuous sweep sinusoidal wave are adopted as input.
• The amplification is induced by a higher mode due to the change of a support condition.

A new interpretation of large amplitude earthquake accelerations recorded at the Kashiwazaki-Kariwa nuclear power station during the Niigata-ken Chuetsu-oki earthquake in 2007 is provided from the viewpoint of non-linear local interaction between an embedded building and its surrounding soil. An occurrence mechanism is investigated by the dynamic response analysis in which a bi-linear restoring-force characteristic with a gap-slip process is used. The Ricker wavelet and the continuous sweep sinusoidal wave are adopted as an input. The amplification is explained to be induced by an additional higher mode due to the change of a support condition, such as a gap between an embedded building and its surrounding soil.