• Title/Summary/Keyword: 지질공학

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Relationship between Hydrogeological Characteristics and Subsurface Geology in Central Busan Megacity (부산광역시 도심부 수리지질 특성과 지하지질 발달상태의 관련성)

  • Ryu, Sang-Hun;Hamm, Se-Yeong;Cha, Yong-Hoon;Jang, Seong;Jeong, Jae-Hyeong;Son, Moon;Kim, Ki-Seok
    • The Journal of Engineering Geology
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    • v.17 no.3
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    • pp.367-379
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    • 2007
  • This study intended to evaluate hydrogeological characteristics in relation to subsurface geology data obtained from borehole, groundwater level, borehole flowmeter test, and field hydraulic tests. The regression equation of groundwater level (Y) versus ground elevation (X) is expressed by Y=0.75X-7.00 with quite high correlation coefficient of 0.78. Relationship between groundwater level and thickness of landfill, alluvium, and weathered zone results in higher correlation of groundwater level (Y) versus natural log value of weathered tone (A) than other correlations, with the regression equation Y= exp(9.974A)-14.155. The result of groundwater flow measurement in the boreholes indicates that groundwater flows towards between south and southwest, and this approximately agree with regional distribution of groundwater levels.

Effect of Rainfall Intensity, Soil Slope and Geology on Soil Erosion (토양침식에서의 강우특성, 토양경사 및 지질의 영향)

  • Nam, Koung-Hoon;Lee, Dal-Heui;Chung, Sung-Rae;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.24 no.1
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    • pp.69-79
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    • 2014
  • This study aims to elucidate the relative importance of geological characteristics, soil slope, and rainfall intensity in relation to soil erosion. To this end, indoor rainfall simulation experiments were carried out under different conditions of rainfall intensities, soil slope, and geological characteristics. The test results show that the factors affect soil erosion in the order of soil slope > rainfall intensity > organic content in the soil. Erosion rates were proportional to rainfall, and increase with increasing clay content. Therefore, the soil erosion rate increases strongly with increasing organic content and clay content. The results show that the soil erosion rate in areas of metamorphic rocks shows a marked increase compared with areas of steep slope and sedimentary rocks. These results indicate that the geological characteristics to produce soil are closely related to sedimentation before and after erosion, providing basic information for the development of models to predict soil erosion rates.

Radon Concentration in Groundwater of Korea (전국 규모로 본 국내 지하수의 라돈 함량)

  • Cho, Byong-Wook
    • The Journal of Engineering Geology
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    • v.28 no.4
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    • pp.661-672
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    • 2018
  • Radon concentration was measured in a total of 5,453 groundwater samples from wells across Korea. The radon concentrations showed the values ranging from 0.1 Bq/L to 7,218.7 Bq/L, with a median of 48.8 Bq/L which is lower than those of other countries having similar geological conditions. The distribution of radon concentrations was lognormal. The median value is high in the granite areas (63.5-105.1 Bq/L) while it is low in the sedimentary rocks and Cheju volcanic area (16.0-20.3 Bq/L). When grouping the groundwater with well depth, the median radon value is high in weathering and/or upper bedrock zone (61.4 Bq/L) while it is low in alluvium and/or weathering zone (28.5 Bq/L). About 17.7% of the total samples exceeded 148 Bq/L of USEPA guideline value. The exceeding radon ratio more than 148 Bq/L in groundwater is highest in Jurassic granite area, however, the exceeding radon rates more than 300 Bq/L and 500 Bq/L are highest in CGRA area.