2024-03-29T08:43:43Z
https://repository.dl.itc.u-tokyo.ac.jp/oai
oai:repository.dl.itc.u-tokyo.ac.jp:00032507
2022-12-19T05:37:58Z
80:4535:4597:4598
9:504:4538:4599:4600
大加速度記録における地盤非線形性に着目したK-NET・KiK-net・JMA震度計ネットワークの強震観測記録に対するスペクトルインバージョンで抽出したサイト特性
Site Effects Derived from Spectral Inversion Method for K-NET, KiK-net, and JMA Strong-Motion Network with Special Reference to Soil Nonlinearity in High PGA Records
Kawase, Hiroshi
124778
51.1
Spectral inversion
nonlinearity
site effects
strong motion
PGA
application/pdf
In this study we first try to separate so-called source spectra, attenuation coeffcient, and site amplification factors from K-Net, KiK-net, and JMA strong-motion (Shindo-kei) network records observed throughout Japan. As a reference site, we use one rock station of KiK-net, and we remove a very small site effect caused by weathered layers from the record using 1-D theoretical amplification. Once we obtain site amplification factors, we try to obtain nonlinear site factors for high PGA records observed during the 2003 Tokachi-Oki earthquake as a ratio of the observed record with respect to the hypothesized input bedrock motion calculated as an average from small PGA (i.e., less than 200 Gals) records. When we compare these site effects with linear site effects for smaller PGA records, we find that several sites show lower peak amplitude with lower peak frequency than expected from previous studies. However, at a few very soft sites we found higher peak amplitude with lower peak frequency. This phenomenon can be interpreted to occur as the impedance effect (makes amplitude higher) is strengthened by nonlinearity, and overcomes the damping effect (makes amplitude lower).
departmental bulletin paper
東京大学地震研究所
2006
application/pdf
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo
3-4
81
309
315
AN00162258
00408972
https://repository.dl.itc.u-tokyo.ac.jp/record/32507/files/IHO81316.pdf
eng