• Journal of the Korean GEO-environmental Society
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• v.20 no.5
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• pp.47-55
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• 2019

This study aims to provide basic data for soil packaging differing in accordance with the strength characteristics of mixed soil, using E.S.B. (Eco Soil Binder), an eco-friendly hardening agent, based on the type of soil. The soil used in this study is weathered granite soil readily collected in and around Korea, and is classified into SW, SP and SC according to soil classification systems. The test piece for the unconfined compressive strength test has dimensions of 50 mm in diameter and 100 mm in height, with the mix ratio of E.S.B. proportional to the weight of mixed soil changed from 5% to 10%, 15%, 20%, 25%, and 30%, where compactness of 90% and 100% were applied according to each condition to analyze the unconfined compressive strength characteristics at material ages of 3, 7, and 28 days. Also, the ratio of soil packaging standard strength and unconfined compressive strength was calculated to determine the optimal E.S.B. mix ratio, whereby the field applicability of the unconfined compressive strength using the estimation equation of ACI209R was evaluated.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.3
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• pp.311-316
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• 2007

In this study, we investigated the presence of nitrogen, phosphorus, ions, heavy metals and other contaminations in the water stream and soil of the forest watershed with different geology and vegetations for one year from October 2004 to September 2005. Most of the nitrogen oxide in the soil was in the form of $NO_3^-$, and it appeared that nitrogen contents decreased as the soil depth increased. Nitrogen contents was highest in the basalt area showing 13.3 mg/g in the surface soil and 7.40 mg/g in the subsoil. Phosphorous contents showed no significant variations depending on the soil depth and was higher in the intermediate soil layer(60 cm) than in surface soil (30 cm) in granite and metamorphic rock areas. Nitrogenous compound in the soil water was 8.03 mg/L in the granite area of coniferous forest and 14.79 mg/L in the andesite area of the deciduous forest. Nitrogenous compound in the stream water was 5.53 mg/L in October and 6.99 mg/L in January in the granite area of the coniferous forest and $3.61\sim5.11$ mg/L in the andesite area of the deciduous forest. Phosphates in runoff and stream water were similar in coniferous with in deciduous forests, showing a slight increase(0.090$\sim$0.179 mg/L) in the basalt area. In the coniferous forest, pH showed a significant positive correlation with EC, $Ca^{2+}$ and $Cl^-$ at p < 0.01, and showed a negative correlation with S-Fe and S-Al. Electroconductivity showed a significant correlation of 0.601 with $Ca^{2+}$ and of -0.586 with $NO_3^-$ at p<0.01, and showed a significant correlation of 0.301 with $SO_4^{2-}$ and of -0.295 with S-Fe at p < 0.05. In the deciduous forest, pH showed a positive correlation with $Ca^{2+}$ at p < 0.05, and showed a negative correlation with $K^+$, S-Fe and S-Al at p < 0.01. Electroconductivity showed a significant positive correlation with $Ca^{2+}$ and $Cl^-$ at p < 0.05 and with $NO_3^-$ at p < 0.01.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.229-234
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• 2007

To select the most proper soil for root initiation from stem cuts of Birdsfoot trefoil (Lotus corniculatus L.), eight-week-old stem cuts were cultured on three types of soil [commercial bed soil, decomposed granite (DCG), and river sand] for one month. The results showed that the root initiation ratios on DCG (77.8%) and river sand (70.0%) were relatively high, but the ratio on commercial bed soil (41.1%) was very low. To examine the effect of rare earth (RE) and Indole-3-Butyric Acid (IBA) on root initiation from stem cuts of Birdsfoot Trefoil, stem cuts were cultured on two types of soil (DCG and river sand) with treatment of RE and IBA for one month. The root initiation ratios turned out to be 90.0% (DCG with 60 ppm of RE), 80.0% (river sand with 20 ppm of RE), 96.7% (DCG with 40 ppm of IBA), and 96.7% (river sand with 40 ppm of IBA). These results suggested that the most efficient way for root initiation of Birdsfoot trefoil was to culture the stem cuts on river sand or DCG over 30 days with IBA treatment (40 ppm).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.61-79
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• 2009

This study is for incompatible element contents of Perilla frutescens and Sesamum indicum from the Keumsan: biotite granite, phyllite and shale areas. In the soils, high elements are shown in the granite and phyllite areas, and in the areas of the Perilla frutescens. Positive correlations are distinctive within the granite for the Perilla frutescens, but the shale for the Sesamum indicum. These relationships can be explained with relative propositions of minerals containing the incompatible element. In the plants, high elements are shown in the shale and the Sesamum indicum are high in the comparisons of the same soil types. The low parts are mainly high. Regardless of the soil types, the lower and upper parts, respectively, are high in the Y, Zr and Rb contents for the Perilla frutescens, but, Ta, Nb, Th and U contents for the Sesamum indicum. Positive correlations are distinctive within plants of the phyllite. Comparing with the soil types, all HFS and Cs contents of the LFS in the plants are low with differences of several to hundred times, but high in the Sr contents with differences of several times. In the comparisons between plants and soil types, Y, Zr, Hf, Ta, Nb, Rb, and Sr of the phyllite and Th, U, Ba and Cs of the shale for the Perilla frutescens as well as Y, Zr, Hf, Rb, Sr, Ba and Cs of the phyllite and Ta, Nb, Th and U of the shale for the Sesamum indicum are chemically similar to the soils. In the comparisons of the each parts for the plant types, differences with the soils are big in the granite.

• Journal of the korean society of oceanography
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• v.31 no.1
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• pp.32-36
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• 1996

The oyster shell bed (more than 47 cm thick) atop the Gaipri Point (granite coastal bluff) in the Hampyung Bay, southwest coast of Korea which is a coastal area of southeastern margin of the Yellow Sea basin has been interpreted as unique typhoon deposit formed at about 3610 yr BP or later. The unconformable boundary between the oyster shell bed by typhoon and the granitic soil horizon of the Gaipri Point is 820 cm high above the mean high-tide water level (MHWL). The $^{14}C$ age of the oyster shells is 3610${\pm}$70 yr BP.

• Structural Engineering and Mechanics
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• v.4 no.6
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• pp.631-644
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• 1996

Geomaterials such as soil and rock are composed of discrete elements of microstructures with different grains and microcracks. The studies of these microstructures are of increasing interest in geophysics and geotechnical engineering relating to underground space development We first show experimental results undertaken for direct observation of microcrack initiation and propagation by using a newly developed experimental system, and next a homogenization method for treating a viscoelastic behavior of a polycrystalline rock.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.59-64
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• 1998

The environmental problem of the rural area has been accelerated in soil as well as water. Soil contamination is usually caused by improper operation of landfills, abandoned mine fields, accidental spills, and illegal dumpings. Once soil contamination is initiated, pollutants migrate and may cause groundwater contamination which takes much effort for remediation. Early detection, therefore, is important to prevent further contamination. Electrical resistivity method was used to detect soil contamination, but it was not effective to the heterogeneous condition. Static cone penetrometer test (CPT) has been used widely to investigate geotechnical properties of the underground. In this study, electrical resistivity method and CPT are combined to improve the applicability of it. The pilot test was performed to examine the variation of electrical resistivity with different soil minerals and pore fluid characteristics. Soil samples used were poorly graded sand, silty sandy soil, and weathered granite soil. For all the cases, electrical resistivity decreased with increasing of moisture content. Soil mineral also affected the electrical resistivity significantly. Above all, leachate addition in the pore fluid was very sensitive and caused decreasing of electrical resistivity markedly. It implies that electrical resistivity method can be applied to investigate pollutant plume effectively. This is specially sure when the sensors contact the contaminated soils directly. The CPT method involves cone penetration to the ground, therefore, underground contamination around the cone could be investigated effectively even for heterogeneous condition as it penetrates if electrical resistivity sensors are attached on the cone.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.1
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• pp.14-22
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• 2008

The forest soil sediment disasters occurred in Jinbu-myeon Pyeongchang county were investigated characteristics by the aerial photograph analysis. After digitizing from aerial photographs, forest soil sediment disaster sites were classified into 695 collapsed sites, 305 flowed sites and 199 sediment sites. DEM (Digital Elevation Model) were generated from 1 : 5,000 digital topographic map. Factors of geography, hydrology, biology, and geology were analyzed using DEM, geologic map, and forest stand map with aerial photographs by GIS spatial analysis technique. The forest soil sediment disasters were mainly occurred from southeastern slope to southwestern slope. In collapsed sit es, the average slope degree is $28.9^{\circ}$, the average flow length is 163.5m, the average area of drainage basin is 897$m^2$. In case of flowed sites, the average slope degree, flow length, the area of drainage basin and confluence order is $27.0^{\circ}$, 175m, 2,500$m^2$ and 1, respectively. In sediment sites, the average slope, flow length, the area of drainage basin and confluence order is $12.5^{\circ}$, 2,50m, 25,000$m^2$ and 4, respectively. Also the forest soil sediment disasters were occurred most of collapsed sites in the afforest land after felling and igneous rocks composed of granite.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.5
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• pp.73-80
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• 2006

The mono-layer cover system is composed of soils only as a filling material and various plants are planted on the surface to control the water balance in the cover system. In this paper, the mono-layer cover system was considered as an alternative landfill final cover system and developed a model that could utilize industrial by-product (especially, coal ash & phosphogypsum) as additive filling materials. The mixture of granite soil, coal ash, and phosphogypsum was placed as a cover material in a box constructed with cement. Laboratory tests were carried out to investigate the environmental effect on the utilization of coal ash & phosphogypsum and to determine the mxing ratio of each materials. In the leaching test, all materials showed lower heavy metal concentration than the threshold values of regulation. The optimum mixing ratio of materials which was applied to field model test was determined to soil (4) : coal ash (1) : phosphogypsum (1) on the volume base. Field model tests were continued from February to July, 2004 in the soil box that was constructed with cement block. It was verified that coal ash and phospogypsum mixed with soil was to be safe environmentally and the water balance of mono-layer cover system was reasonable.

• The Journal of Engineering Geology
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• v.15 no.2 s.42
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• pp.123-132
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• 2005

This study presents the results of a laboratory investigation performed to study physical properties of soil-bentonite mixtures through the vertical permeation test and dielectric measurement test using Frequency Domain Reflectometry system for the liner of waste landfill. For the laboratory experiments, geotechnical testing was conducted on pre-mixed soil-bentonite which is consisted of standard sand, weathered granite soil and bentonite for estimating physical parameters such as a volumetric water content, void ratio and dielectric constant. In experiment results, initial soil-bentonite mixing rate has an effect of change of volumetric water content. Also change of volumetric water content of a soil-bentonite mixture is clearly detected to measure a response of dielectric constant. In order to estimate an unsaturated permeable property of soil-bentonite mixtures, equations between volumetric water content and dielectric constant were derived from this study.