• Korean Journal of Heritage: History & Science
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• v.45 no.4
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• pp.114-125
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• 2012

The purpose of this study is to analysis chromaticity, granulometry, main chemical composition and mineral crystal structure of wall soils excavated from Poongnatoseong Earthen Castle using color reader, XRD, particla size analyzer. The analysed soils of Poongnatoseong Earthen Castle were yellowish brown and isabella. All samples were sands or sands including silty soil(SW~SC) and showed similar granulometry, chemical composition and mineral crystal structure, which were characteristics of construction materials suitable for modern road or airstrip. As resulting in comparison with 4 factors from chromaticity, granulometry, main chemical composition and mineral crystal structure, we decided that the control soils(PNS) near by Poongnatoseong Earthen Castle were not to be used for the castle wall construction We presumed that there was a huge soil distribution area for the wall construction around Poongnatoseong Earthen Castle. For further study, we will make a comparison analysis all kinds of soil characteristics. And then we can understand correctly about wall soils producing area, construction method, repair method and time of Poongnatoseong Earthen Castle.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.491-498
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• 2005

Acid Rock Drainage(ARD) is the product formed by the atmospheric(i.e. by water, oxygen and carbon dioxide) oxidation of the relatively common iron-sulphur minerals pyrite($FeS_2$). ARD causes the acidification and heavy metal contamination of water and soil and the reduction of slope stability. In this study the generation characteristics and the prediction of ARD of various road cut slopes were studied. An attempt to classify the rocks into several groups according to their acid generation potentials was made. Acid Base Accounting(ABA) tests, commonly used as a screening tool in ARD predictions, were performed. Sixteen rock samples were classified into PAF(potentially acid forming) group and four rock samples into NAF(non-acid forming) group. The chemical analysis of water samples strongly suggested that ARD with high content of heavy metals and low pH could pollute the ground water and/or stream water.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.847-854
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• 2004

The resistivity of soils depends on grains size, porosity, water saturation, pore fluid resistivity, caly contents and son on. It is very important to understand the relationship between resistivity and such physical properties of soils, in order to interpret and evaluate ground conditions by using resistivity data obtained from electrical resistivity prospecting. In this paper, to study the relationship between resistivity and physical properties of soils, the resistivity of glass beads and compacted soil samples both in saturated and unsaturated conditions is measured. As the results, the resistivity of saturated soils depends mainly on porosity and clay contents, while that of unsaturated soils is sensitive to compaction conditions, and decreases with increasing water content until the optimum water condition, that is the maximum dry density. But, the relationship between resistivity and water saturation for soils is unique, being independent of compaction energy. Also, the resistivity ratio decrease with increasing water saturation, followed by no significant change of resistivity ratio over 80 percent of water saturation (the optimum water content).

• Geomechanics and Engineering
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• v.35 no.2
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• pp.109-119
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• 2023

Ground subsidence in urban areas due to excessive development and degraded underground facilities is a serious problem. Geophysical surveys have been conducted to estimate the distribution and scale of cavities and subsidence. In this study, electrical resistivity tomography (ERT) was performed near an area of road subsidence in an urban area. The subsidence arose due to groundwater leakage that carried soil into a neighboring excavation site. The ERT survey line was located between the main subsidence area and an excavation site. Because ERT data are affected by rapid topographic changes and surrounding structures, the influence of the excavation site on the data was analyzed through field-scale numerical modeling. The effect of an excavation should be considered when interpreting ERT data because it can lead to wrong anomalous results. A method for performing 2D inversion after correcting resistivity data for the effect of the excavation site was proposed. This method was initially tested using a field-scale numerical model that included the excavation site and subsurface anomaly, which was a loosened zone, and was then applied to field data. In addition, ERT data were interpreted using an existing in-house 3D algorithm, which considered the effect of excavation sites. The inversion results demonstrated that conductive anomalies in the loosened zone were greater compared to the inversion that did not consider the effects of excavation.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.72-77
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• 2007

Soil contamination by heavy metals was environmental concern due to its effect on human. In this study, monopotassium phosphate $(KH_2PO_4)$ used as phosphate source to remediate the contaminated soil with heavy metals and factors such as reaction time, initial concentration and pH of phosphate solution, species of heavy metal (lead, cadmium, zinc) and particle size were controlled. Heavy metals were removed in the order Pb > Zn > Cd and the maximum effectiveness was achieved for Pb. The removal efficiency of lead was from 95% to 100% and occurred rapidly occurred during 10 minutes. Mechanism of lead immobilization is dissolution of phosphate and the forming of a new mineral with phosphate having extremely low solubility.

• Journal of the Korean Geotechnical Society
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• v.28 no.3
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• pp.45-54
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• 2012

Various geosynthetics are widely applied to civil structures and waste landfill site for reinforcement and water resistance. The use of geosynthetics inevitably involves the coupled behaviors of different materials which include large displacement and strain-softening behaviors, etc. In this study, the effect of chemical element in the leachate on the interface shear strength under the cyclic loading condition was analyzed. The Multi-purpose Interface Apparatus (M-PIA) has been modified and cyclic direct shear tests have been performed. The submerging period of each specimen is 200 days. Additionally, the Field-Emission Scanning Electronic Microscopy (FIB) analysis has been also performed to induce the reason of the variation of disturbance function and verify the hypothesis on the decay-proof ability of geosynthetics. Consequently, the charateristics of chemical degradation of geosynthetic-soil interface are verified and the variation of the disturbance function is mainly caused by the different type of soil mineral decay, based on the FIB results.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.391-397
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• 2014

Acid mine drainage occurrence is a serious environmental problem by mining industry; it usually contain high levels of metal ions, such as iron, copper, zinc, aluminum, and manganese, as well as metalloids of which arsenic is generally of greatest concern. It causes mine impacted soil pollution with mining and smelting activities, fossil fuel combustion, and waste disposal. In the present study, three bacterial strains capable of producing urease were isolated by selective enrichment of heavy metal contaminated soils from a minei-mpacted area. All isolated bacterial strains were identified Sporosarcina pasteurii with more than 98% of similarity, therefore they were named Sporosarcina sp. KM-01, KM-07, and KM-12. The heavy metals detected from the collected mine soils containing bacterial isolates as Mn ($170.50mg\;kg^{-1}$), As ($114.05mg\;kg^{-1}$), Zn ($92.07mg\;kg^{-1}$), Cu ($62.44mg\;kg^{-1}$), and Pb ($40.29mg\;kg^{-1}$). The KM-01, KM-07, and KM-12 strains were shown to be able to precipitate calcium carbonate using urea as a energy source that was amended with calcium chloride. SEM-EDS analyses showed that calcium carbonate was successfully produced and increased with time. To confirm the calcium carbonate precipitation ability, urease activity and precipitate weight were also measured and compared. These results demonstrate that all isolated bacterial strains could potentially be used in the bioremediation of acidic soil contaminated by heavy metals by mining activity.

• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.36-45
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• 2016

Variability in precipitation due to climate change causes difficulties in securing stable surface water resource, which requires understanding of relation between precipitation and stream discharge. This study simulated stream discharge in a small mountainous forested catchment using antecedent precipitation index (API) models which represent variability of saturation conditions of soil layers depending on rainfall events. During 13 months from May 2015 to May 2016, stream discharge and rainfall were measured at the outlet and in the central part of the watershed, respectively. Several API models with average recession coefficients were applied to predict stream discharge using measured rainfall, which resulted in the best reflection time for API model was 1 day in terms of predictability of stream discharge. This indicates that soil water in riparian zones has fast response to rainfall events and its storage is relatively small. The model can be improved by employing seasonal recession coefficients which can consider seasonal fluctuation of hydrological parameters. These results showed API models can be useful to evaluate variability of streamflow in ungauged small forested watersheds in that stream discharge can be simulated using only rainfall data.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.97-103
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• 2016

BACKGROUND: Clay mineral is well known to improve physico-chemical of soil. The objective of this study was to investigate the growth characteristics and inorganic nutrient contents of crops with application levels of phyllite.METHODS AND RESULTS: Both young radish and lettuce were selected as target crops for this study. The experiment was conducted in a wagner pot(1/5000a) in glass house at Sunchon National University. Treatment conditions were divided P0NPK(No phyllite + NPK), P5NPK(phyllite 5 Mg/ha + NPK), P10NPK(phyllite 10 Mg/ha + NPK) and P15NPK(phyllite 15 Mg/ha + NPK) by crops, respectively. Bulk density and porosity of soil in control without treatment conditions were ranged from 1.02 ∼1.04 g/cm³ and 56.5∼57.0%, respectively, and those for treatments with phyllite were in the ranged from 0.94∼1.00 g/cm³ and 58.4∼63.5%, respectively. Dry weights of young radish and lettuce were higher in P15NPK treatment than those in other treatments. The amounts of T-N, T-P and K uptake in young radish with phyllite application treatments were increased 36∼115, 18∼67 and 20∼76% than without phyllite application treatment, respectively. In lettuce treatments, amounts of T-N, T-P and K uptake were intended to all tested treatments similar with result of young radish treatment.CONCLUSION: Therefore, these results confirm that phyllite application to the soil improves physico-chemical of soil in addition to improving growth of young radish and lettuce.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.85-91
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• 2014

In this study, the water quality purification of new medias which were NPS media, hyugato, mineral stone, charcoal for applying soil media of Integrated Management Practices (IMPs) of Low Impact Development (LID) were evaluated. The influent concentrations of COD, T-N, and T-P were 117.8 mg/L, 17.1 mg/L, and 2.062 mg/L, respectively. The infiltration capacities of NPS media, hyugoto, mineral stone, charcoal, and gravel were $7.1{\times}10m/s$, $7.3{\times}10^{-5}m/s$, $7.9{\times}10^{-5}m/s$, $6.0{\times}10^{-5}m/s$, respectively. All media meet criteria of infiltration capacity as surface soil layer at IMPs which is over $1.0{\times}10^{-5}m/s$. Maximum removal rates of COD, T-N, and T-P occurred at Charcoal with 98 % of COD removal rate, NPS with 78 % of T-N removal rate, and hyugato with 75 % fo T-P removal rate, respectively. For more high removal efficiency of all water quality item, the mixed media which is 4.5(NPS media): 1(charcoal) : 4.5 (hyugato) as volume ratio was evaluated. The infiltration capacity of mixed media was $7.9{\times}10^{-5}m/s$ and met the criteria of infiltration as surface soil layer. The water quality removal efficiencies of mixed media were very high with showing 70 % for COD, 85 % for T-N, and 71 % for T-P. The mixed media could purify the water quality of surface runoff and was recommended to used at the LID site of ground water quality problem.