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http://dx.doi.org/10.9720/kseg.2021.2.211

Thickness Analysis of the Alluvium and Yeonil Group in Pohang Area through the Microtremor HVSR Techniques  

Kim, Jeonghyun (Geoscan)
Ki, Jungseok (Geoscan)
No, Younghwa (Geoscan)
Publication Information
The Journal of Engineering Geology / v.31, no.2, 2021 , pp. 211-222 More about this Journal
Abstract
The magnitude 5.4 earthquake occurred in 2017 near 7.5 km north of Buk-gu, Pohang. In order to find out the characteristics of microtremor in Buk-gu, Pohang, Gyeongsangbuk-do, where earthquake damage occurred significantly, a total of 39 points were acquired to analyze the horizontal to vertical spectral ratio (HVSR). Microtremor vary from region to region, so the resonant frequency of the region is obtained by examining the microtremor. For Thickness analysis, we analyze the structure and properties of shear wave velocity (Vs) up to the underlying rock to compare resonance frequencies to match the horizontal to vertical spectral ratio (HVSR) analysis technique against nearby boring data. Using F0 = Vs/4H with a resonance frequency of alluvium is 1.3 ± 0.07 Hz and a resonance frequency of Yeonil group is 0.69 ± 0.22 Hz, the alluvium thickness was found to be 26~30 m and the Yeonil group thickness was 170~250 m.
Keywords
HVSR; resonance frequency; shear wave velocity; thickness;
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Times Cited By KSCI : 1  (Citation Analysis)
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