岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

時間領域差分法による表層地盤の非線形応答の計算

TORIGOE, Yusuke Department of Earth Sciences, Faculty of Science, Okayama University
KOMATSU, Masanao Graduate School of Natural Science and Technology, Okayama University
TAKENAKA, Hiroshi Graduate School of Natural Science and Technology, Okayama University Kaken ID publons researchmap
Abstract
We have developed a time-domain staggered-grid finite-difference code for modeling non-linear response of a one-dimensionally inhomogeneous subsurface structure to a SH plane-wave incidence. It employs the velocity-stress formulation of elastodynamic equation for the linear part, and adopts a elastoplastic rheology model for the non-linear relation between the stress and strain. In this paper, we apply this code to four constitutive models from linear-elastic to nonlinear: (1) linear elastic model, (2) linear viscoelastic model, (3) elastoplastic model, and (4) viscoelastoplastic model, which simulate shallow sand and clay structures and are vibrated by a vertically incident SH plane-wave of Ricker wavelet, to compare the linear and the non-linear soil behaviors including low strains damping (viscoelastic effect) and/or hysteretic attenuation (non-linear effect). We also apply it to a local strong-motion record of the 2000 Western-Tottori earthquake (MW6.8). We then simulate characteristics of non-linear site response such as reduction of the spectral amplitude in the high frequency band and shift of the peak frequencies to lower frequencies.
Keywords
finite-difference method
non-linear site response
strong motion
ISSN
1340-7414
NCID
AN10506284