A STUDY ON LOCAL SITE EFFECTS USING AN ARRAY OBSERVATION SYSTEM OF STRONG MOTIONS
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- KAMIYAMA Makoto
- 東北工業大学環境情報工学科
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- MATSUKAWA Tadashi
- 東北工業大学環境情報工学科
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- KATAOKA Shunichi
- 弘前大学理工学研究科
Bibliographic Information
- Other Title
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- アレー強震観測システムを利用したローカルサイト増幅に関する研究
Abstract
The purpose of this paper is to compare spectral characteristics of strong ground motions and microtremors using records obtained at 20 sites of an array observation system. The array observation system is situated in Sendai City, Japan. Using the motion records observed by the system, the authors estimated statistically spectral amplification factors at each observation site. These spectral amplification factors of strong ground motions are quite different depending on the local soil condition of each site. Microtremors were also observed at all the observation sites. The so-called H/V spectra, which are the spectral ratio of the horizontal component to the vertical one, were obtained from the microtremors. Comparisons between the statistical amplification factors of strong motions and H/V spectra of microtremors showed that they have strong similarity in spectral shape. Although such highly similar shape of spectra was found between the strong motions and microtremors, the absolute spectral amplitudes in both indicated a difference in level, revealing some remarkable offsets of spectral amplitude that are independent of period. Based on the comparisons, fitting analyses between the spectral amplification factors and H/V spectra of microtremors were made to obtain an optimal parameter of offset for the H/V spectra of microtremors. This paper finally concludes that microtremors are useful to obtain amplification factors due to local soil conditions with aid of an offset method of their H/V spectra.
Journal
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- Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE))
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Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)) 65 (1), 38-51, 2009
Japan Society of Civil Engineers
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Keywords
Details 詳細情報について
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- CRID
- 1390282680328192512
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- NII Article ID
- 130004961172
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- ISSN
- 21854653
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- Data Source
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- JaLC
- Crossref
- CiNii Articles
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- Abstract License Flag
- Disallowed