Examination of relation between locations of asperities and site amplification characteristics of ground motions by analysis considering the folded structure - Estimation based on the strong motion records obtained from the 2007 Niigataken Chuetsu-oki earthquake in the Kashiwazaki-Kariwa Nuclear Power Station

This paper investigates factors causing difference of site amplification in the Kashiwazaki-Kariwa Nuclear Power Station in the 2007 Niigataken Chuetsu-oki earthquake. To consider 3D response by asperities outside the section of 2D folded structure, FEM analysis is performed with vertical and horizontal incident angles. At Unit 1 above syncline, amplification of 2D model is larger than that of 1D model directly under the point when incidence is closer to vertical as the third asperity. This is due to folds of both first and second boundaries. At Unit 5 above anticline, amplification of 2D model corresponds to that of 1D model.