• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.397-400
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• 2003

In this study, humic and fulvic acids in soils at the vicinity of domestic atomic power plants(NPPs), located in Yungkwang(YK), Uljin(UJ), Kori(KR), Koseong(KS), Wolseong(WS) area, and in volcanic ash soils of the Cheju island(Mt. Hanla(HL), Manjanggul(MJ)) were isolated, and characterized using chemical(elemental analysis, proton exchange capacity, molecular size distribution) and spectroscopic(UV/Vis., IR, FL, $^{13}$ C NMR spectra) methods. The results were compared with one another and compiled for their DB establishments. The humic substances distribution (humic acid, fulvic acid, Humin) in the soils were also determined by IHSS standard method. Main purpose of this study was to provide a basic data needed to evaluate the effect of humic substances on the migrational behaviour of radioactive elements in contaminated surface soil.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.84-91
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• 2005

In case of soil nailing system, there have been many attempts to expand into slope and temporary earth retaining system stabilization method since the first ground excavation earth retaining system construction in 1993. Recently, jointing wall, underground wall of buildings and excavation earth retaining wall, construction were increasingly applied for effective utilization of the limited underground space and land application maximized. However, the application of joining wall into retaining wall or building by temporary soil nailing system and design of permanent wall were performed by using Rankine earth pressure theory without considering the distribution of earth pressure in the soil nailing. In this study was performed to introduce the design case by 'Two-Body Translation mechanism (TBTM)' to be able to consider distribution of earth pressure in the soil nailing when designing the permanent jointing wall using soil nailing system for effective utilization of ground space. Also, this study attempts to evaluate the earth pressure change, decreasing effect of wall displacement and increasing effect of stability when advanced soil nailing system is constructed using $FLAC^{2D}$ ${\nu}er.$ 3.30 program and 'Two-Body Translation mechanism'.

• 한국토양동물학회지
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• 제1권1호
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• pp.37-47
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• 1996

This research was carried out to investigate soil mictoarthropods fauna in Namsan and Kwangreung which were considered to receive different degreeds of environmental pressures. In basic environmental data, Namsan where under rather accelerated acidification by air contamination and acidic rain showed low pH, tardy decomposition and turnover rate. Population density of soil microarthropods was high in Kwangreung 17,169.8/\ulcorner\ulcorner(coniferous forests), 17,892.6/$\textrm{m}^2$(deciduous forests) than in Namsan, 12,143.8/$\textrm{m}^2$ (coniferous forests), 14,216$\textrm{m}^2$(deciduous forests). Biomass of soil microarthropods was 2,020.219mg/$\textrm{m}^2$ at coniferous forests and 4,270.172mg/$\textrm{m}^2$ at deciduous forests in Namsan, and 3,287.326mg/$\textrm{m}^2$ at coniferous forests and 4326.1mg/$\textrm{m}^2$ at deciduous forests in Kwangreung. Population density constantly showed high in spring, and seasonal fluctuations were correlated with seasonal precipitation. As far as vertical distribution is concerned, population density was concentrated in litter layer as 70% while 30% are in soil layer and also decreased with increasing depth.

• Geomechanics and Engineering
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• 제35권4호
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• pp.385-393
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• 2023

To analyze the consolidation with horizontal sand drains, the plane strain consolidation model under multi-ramp loading is established, and its corresponding analytical solution is derived by using the separation of variables method. The proposed solution is verified by the field measurement data and finite element results. Then, the effects of the loading mode and stress distribution on consolidation and dissipation of pore pressure are investigated. At the same time, the influence of hydraulic conductivity and thickness of sand blankets on soil consolidation are also analyzed. The results show that the loading mode has a significant effect on both the soil consolidation rate and generation-dissipation process of pore water pressure. In contrast, the influence of stress distribution on pore pressure dissipation is obvious, while its influence on soil consolidation rate is negligible. To guarantee the fully drained condition of the sand blanket, the ratio of hydraulic conductivity of the sand blanket to that of clay layer k_d/k_v should range from 1.0×10⁴ to 1.0×10⁶ with soil width varying from 100 m to 1000 m. A larger soil width correspondingly needs a greater value of kd/kv to make sure that the pore water can flow through the sand blanket smoothly with little resistance. When the soil width is relatively small (e.g., less than 100 m), the effect of thickness of the sand blanket on soil consolidation is insignificant. And its influence appears obvious gradually with the increase of the soil width.

• 아시안잔디학회지
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• 제19권2호
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• pp.95-102
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• 2005

USGA green specification is currently accepted in construction method of Korea. This study was carried out to find the factors influencing growth of turfgrass associated with soil physical properties of soil root-zone on golf green constructed with USGA method. Three putting greens in poor turfgrass and one in good turfgrass condition were selected for investigation on one golf course site at mid-South Korean peninsula. Soil hardness, moisture content, root length, and turf density were measured on-site greens, and soil physical properties and soil chemical properties also analyzed in laboratory. As a result of on-site surveys and soil physical tests in laboratory, soil physical properties were most important factors which influenced on turfgrass growth at tested greens. The results of soil particle analysis on green No. 2, in good turf condition, matched USGA sand particle recommendations. But those greens such as Nos. 1, 11 and 16, in poor putting greens, showed high soil compaction and improper soil particle distribution. Those factors created low leaf density, poor root depth, and higher moisture content compared with lower part of topsoil. Such phenomena caused inadequate turfgrass growth with soil hardening associated with poor drainage. Therefore, declines of soil physical properties associated with improper particle distribution caused a major factor influencing on turfgrass growth in golf green. Adequate test of soil particle analysis by USGA specification and proper construction method followed by adequate turf maintenance should be performed to obtain optimal turf quality on putting green.

• Environmental Analysis Health and Toxicology
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• 제22권2호통권57호
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• pp.129-135
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• 2007

Polycyclic aromatic hydrocarbons(PAHs) have been analyzed to assess vertical distribution of them with different land uses. The soils were collected from three layers; surface $(0{\sim}5cm)$, intermediate $(6{\sim}10cm)$, and deep $(11{\sim}15cm)$ layer, respectively considering land use; paddy, upland, and mountain in each site. Total 89 samples of soil from 10 sites were analyzed. Overall mean of ${\sum}PAHs$ were 137 (range $8.87{\sim}625{\mu}g\;kg^{-1}$), 203 (range $16.5{\sim}645{\mu}g\;kg^{-1}$), and $83.4{\mu}g\;kg^{-1}$ (range $6.65{\sim}667{\mu}g\;kg^{-1}$) for paddy, upland, and mountain soil, respectively. The dominant PAHs were fluoroanthene/benzo(b)fluoroanthene>pyrene>indeno(1, 2, 3-cd) pyrene in paddy, fluoroanthene/pyrene>benzo(b)fluoroanthene>chrysene in upland, and benzo(b)fluoroanthene>pyrene>chrysene in mountain soil, whereas the profile was quite similar for each other except that indeno(1, 2, 3-cd)pyrene and benzo(ghi)perylene are relatively higher in the paddy soils. Although the concentration gradient by depth was not observed in the paddy and upland soils because perturbation of soil layer by tillage, significant decrease was in the deep layer relative to the surface and intermediate layer. However, the concentration gradient of PAHs by soil depth was clearly shown in mountain soil without experiencing disturbance of tillage.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권4호
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• pp.48-59
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• 2018

Beryllium (Be), cobalt (Co), thallium (Tl) and vanadium (V) are candidates of 21 priority soil pollutants in Korea. The distribution of their concentration in soils from three contamination sources including industrial, roadside and mining areas was investigated. Concentrations of the metals were evaluated quantitatively using pollution indices and the fractionation of metals was conducted using modified SM&T (Standards Measurements and Testing programme) sequential extraction. Concentrations of the metals for all samples from industrial and roadside soils were within the range of natural background levels, while some of Be in soils from abandoned mines exceeded that the range. Enrichment Factor (EF) and Nemerow Integrated Pollution Index (NIPI) for Be, Co, Tl and V showed that there are effects or possibilities of anthropogenic activities. Pollution Load Index (PLI) analyses indicated all investigated sites needed further monitoring. The results of sequential extractions indicated mobile fractions (F1+F2) of Be, Tl and V were below 30% except some of Co in soil, which implies their low mobility to neighboring environment media. Variable tools like sequential extraction, comparison with background/actual concentration and pollution indices, as well as aqua regia extraction should be considered when evaluating Be, Co, Tl, V in soil.

• 한국지반환경공학회 논문집
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• 제21권11호
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• pp.21-26
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• 2020

자연상태의 흙은 다양한 크기의 입자로 구성되어 있으며, 이 흙의 역학적 거동 중 전단거동은 입도 분포에 크게 영향을 받는다. 그리고 자연상태의 흙은 조립토와 세립토가 다양하게 혼합되어 존재하기 때문에 그 역학적 성질인 전단특성을 명확히 파악하기 어렵다. 이에 본 연구에서는 흙의 입도 분포가 흙의 전단특성에 미치는 영향을 확인하기 위한 목적으로 조립토는 모래를 세립토는 실트를 이용해 모래에 대한 실트의 함유량을 변화시켜 입도 분포가 다른 사질토를 조성한 후 링 전단시험을 수행하였다. 그리고 물 공급 시 입도 분포가 다른 사질토의 전단특성 변화를 확인하기 위해 링 전단시험 중 물을 공급하여 실험을 수행하였다. 그 결과 실트 함유량이 증가할수록 전단강도는 점차 증가하다 실트 함유량이 모래보다 많아지면 전단강도는 감소하는 것으로 나타났다. 그리고 수분 공급 시 실트 함유량에 따라 잔류전단강도는 완만한 경사를 나타내며 감소하는 것으로 나타났다.

• 대한토목학회논문집
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• 제8권3호
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• pp.119-128
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• 1988

본 연구의 목적은 불포화 토양내 유기독성물질의 삼계평형분포에 미치는 함수율(0.3~1.255%)과 온도 ($4{\sim}40^{\circ}C$)의 영향을 정량화 하는데 있다. 본 실험에 사용한 토양은 한국토양의 주종을 이루고 있는 마사토이며, 유기독성물질로써는 Dichlolomethane과 1, 1, 1-Trichloloethane을 사용하였다. 토양내 수분이 분포하는 모양에 따른 두가지 가정(가정 1. 토양수분이 토양입자의 표면을 완전히 둘러싸고 있다. 가정 2. 부분적으로 둘러싸고 있다.)에 기초하여 구한 두 모델과 실험결과를 비교하였다. 이 실험의 결과 함수율이 증가함에 따라 $K_{eff}$ 값은 급격히 감소하는 것을 알았다. 또한 온도가 증가함에 따라 $K_{eff}$ 값은 감소하였는데, 함수율이 낮을수록 이러한 온도의 영향은 더욱 크게 나타났다. $K_{eff}$ 값은, 모델II를 이용하여 구한 예측치와 더 잘 일치하였다. 이 결과로부터 토양의 함수율이 매우 낮을 경우, 토양수분은 부분적으로 토양입자를 둘려싸고 있다는 가정이 타당함을 실험적으로 증명할 수 있게 되었다.

• Journal of Ecology and Environment
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• 제45권4호
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• pp.264-276
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• 2021

Background: Salt marshes provide a variety of ecosystem services; however, they are vulnerable to human activity, water level fluctuations, and climate change. Analyses of the relationships between plant communities and environmental conditions in salt marshes are expected to provide useful information for the prediction of changes during climate change. In this study, relationships between the current vegetation structure and environmental factors were evaluated in the tidal flat at the southern tip of Ganghwa, Korea, where salt marshes are well-developed. Results: The vegetation structure in Ganghwa salt marshes was divided into three groups by cluster analysis: group A, dominated by Phragmites communis; group B, dominated by Suaeda japonica; and group C, dominated by other taxa. As determined by PERMANOVA, the groups showed significant differences with respect to altitude, soil moisture, soil organic matter, salinity, sand, clay, and silt ratios. A canonical correspondence analysis based on the percent cover of each species in the quadrats showed that the proportion of sand increased as the altitude increased and S. japonica appeared in soil with a relatively high silt proportion, while P. communis was distributed in soil with low salinity. Conclusions: The distributions of three halophyte groups differed depending on the altitude, soil moisture, salinity, and soil organic matter, sand, silt, and clay contents. Pioneer species, such as S. japonica, appeared in soil with a relatively high silt content. The P. communis community survived under a wider range of soil textures than previously reported in the literature; the species was distributed in soils with relatively low salinity, with a range expansion toward the sea in areas with freshwater influx. The observed spatial distribution patterns may provide a basis for conservation under declining salt marshes.