2018 Volume 18 Issue 2 Pages 2_166-2_183
We evaluated the influence of nonlinear earthquake response by nonhomogeneous property value distribution model on spatially variation of seismic ground motions and foundation ground stability (minimum slip safety factor) based on numerical experiments, for ground near the building foundation. In order to make the ground that is as close to reality as possible, we used the research building of Kyoto University Nuclear Furnace Research Laboratory and its surrounding ground information where layer structure and variation of S wave velocity in the vertical direction are investigated by boring etc. Regarding the spatially variation of seismic ground motions, the nonlinear analysis of the nonhomogeneous ground model resulted in lower coherence between receiving points of the same horizontal level than linear analysis. Also, fluctuations in Fourier spectral ratio increased. Regarding the evaluation of the minimum slip safety factor of the foundation ground (nonlinear analysis), the nonhomogeneous ground model resulted in an increase in the slip safety factor compared to the homogeneous ground model. Regarding the spatially variation of seismic ground motions, we considered that the main reason was that the variation of each ground element from the initial physical property value (especially shear rigidity) became even larger, when the strong earthquake occurred. Regarding the evaluation of the minimum slip safety factor of the foundation ground (nonlinear analysis), we considered that the main reason was that the variation of the maximum shear stress aspect of each element becomes large.
