• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.137-144
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• 1999

Recently a removable soil nail is demanded due to problems beyond of economical and engineering purpose. In this study removable soil nails are developed and field pull-out tests are carried out 16 times in order to analysis pull-out characteristics of the removable soil nail. For the spacing and the installed position of fixed socket, the length of the soil nail, and W/C ratio of cement grout in the removable soil nail, pull-out characteristics of pull-out tests are analyzed. From the pull-out characteristics of removable soil nails, it is found that the spacing of fixed socket and W/C ratio of cement grout are important design parameters.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.2
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• pp.49-57
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• 1987

This study had been conducted to determine morphological characteristics of soil in the major districts cultivating flue-cured tobacco plant. Also native soil productivities were measured by means of bioassay planting tobacco plant without fertilizer at 87 selected soils through field experiment. Morphological characteristics of troll affecting the dry weight of tobacco leaves cultivated in the field were investigated Among soil morphological characteristics, topograpy, slope, topsoil depth, soil depth, and soil texture had influenced with high significant on the dry weight of tobacco leaves. For prediction of dry weight (productivity) of tobacco leaves without fertilizer , multiple regression analysis were introduced using soul morphological characteristics. A combination of topography, slope, topsoil depth, and soil texture was very reliable for prediction of productivity. The regression equation was y = -16.88 -14, 34$X_1$ +20.43$X_2$ +50.21$X_3$ -7.54$X_4$ +13.45$X_5$ R = $0.670^{**}$ Where $X_1$ : Topography $X_2$ : Slope $X_3$ : Topsoil Depth $X_4$ : Soil Depth $X_5$ : Soil Texture

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.9-13
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• 2002

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with cement. And confirm the reinforcing effects with admixture such as cement. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and cement reinforced soil. In order to determine proper moisture content and mixing ratio, pilot test was carried out for soil and cement reinforced soil. And the mixing ratio of cement admixture was fixed 3%, 6%, 9% and 12% by the weight of dry soil. As the experimental results, the maximum dry unit weight(${\gamma}_{dmax}$) was increased with the mixing ratio and then shown the peak at 10% reinforced soil, but the optimum moisture content(OMC) and the volume change was decreased with the ratio increase. And the compressive strength volume change was decreased with mixing ratio increased.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.319-322
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• 2002

The bacterial transport in soil media was studied. Nonionic surfactants, enhanced the bacterial transports in soil media. The transport rate in soil column was increased by increasing the number of ethylene oxide in polyoxyethylene oxide surfactants. Ionic strength of solution affected the microbial transport characteristics in soil. The hydrophobicity of cell surface was proved that one of important characteristics on the bacterial transport in soil media.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.4
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• pp.99-109
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• 1997

To estimate the nutrients delivery characteristics of Chogang stream to Keum River, sediment and soil characteristics were analyzed in the stream and in the stream bank. Along the stream, soil samples from river sediment were collected and tested monthly for phosphorus and nitrogen concentrations. Nitrogen concentration in the sediment is much lower than that of soil in the river bank especially in summer presumably due to the high desorption characteristics of nitrogen by the increasing rainfall energy during summer. Instead, the concentrations of phosphorus were similar for the sediment and the soil in the river bank due to the strong adsorption characteristics of phosphorus. Batch tests were performed to evaluate the desorption potential of the sediments. Universal Soil Loss Equation (USLE) was applied to quantify soil erosion in each watershed due to rainfall. It was estimated that approximately 25% of total phosphorus by mass basis could be released from the sediment if the water was disturbed vigorously. The mass load of nitrogen and phosphorus into the Chogang Stream from the watershed were evaluated from the USLE and release ratio of phosphorus.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.3
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• pp.49-54
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• 2001

It is common that the soil layer is a few meters below the earth's surface and the rock mass is below the soil layer in the view of geological characteristics in Korea. And the boundary between rock and soil is clearly divided. When dealing with the stability of rock masses, as in the case of rock slopes or dam foundations, the majority of the collapses is not within the soil layer, but within the soil-rock boundary. Therefore it is important to identify the shear strength characteristics between soil-rock boundary. And then in the method of reinforcement on landslide this chose a cut slope near Daemo elementary school in Seoul, surveyed shear strength between soil-rock contacts and considered a large scale collapse using a limit equilibrium method.

• Journal of the Korean GEO-environmental Society
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• v.15 no.3
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• pp.49-55
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• 2014

Characteristics of sedimentation of dredged soil is depended on the field condition and characteristics of dredged soil because dredged fill ground was formed by various field condition, sedimentation and self-weight consolidation process of dredged soil. Dredged fill ground is formed as separated sedimentary layer by characteristics of dredged soil. Therefore, it requires some special test method to consider a various field condition, characteristics of sedimentation and self-weight consolidation of dredged soil. In this study, in order to identify the characteristics of sedimentation of dredged soil with disposing velocity geo-centrifuge test and laser particle size analyzer were performed. As a results, river and mixed dredged soil show the separation sedimentation by soil particle size. And sedimentation of clayey dredged soil is parallel to the bottom surface of dredged fill space.

• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.208-211
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• 2011

The lowest amount of heavy metals was found outside the city (25 km away), the highest amount was found near the thermoelectric power plant, and the average amount was discovered in the central part of the city. The presence of heavy metals in soil samples resulted in reduction of several important soil characteristics (pH, humus content, soil "breathing"). Use of simple and quick methods to examine soil with high heavy metals pollution resulted in the discovery of a pedobiota group, consisting of nematodes, fungi (genus Fusarium) and Protozoa which indicated the toxicity of the Almaty city soils.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.147-152
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• 2001

This study investigated one-dimensional vertical infiltration to an unsaturated residual soil by numerical solutions, FDM. In order to estimate the parameters needed for numerical analysis, tire soil-water characteristic curve(SWCC) of Shinnae-dong soil, one of the most typical residual soils in Korea, were experimentally obtained. Then, the statistical analysis for obtaining the SWCC was performed. The numerical solution to the linearized governing equation for unsaturated groundwater flow provides the infiltration characteristics for the unsaturated residual soil represented by transient pressure profiles and water contents profiles.

• Journal of Plant Biology
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• v.21 no.1_4
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• pp.7-12
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• 1978

The results of the relationship between standing crop of Miscanthus sinensis grassland and soil morphological characteristics are as follows. The Miscanthus sinensis grassland seems to grow well in volcainc ash soil. The depth of A layer was closely related to the standing crop of the Miscanthus sinensis grassland. The root systems of Miscanthus sinensis reached to its maximum in A layer. The root systems of Miscanthus sinensis showed its maximum at 20mm and below(soil hardness). The soil texture of A layer showed SL-SiL. The soil structure of A layer contained Massive-Small Granular. The soil colors of A layer expressed Dark Yellowish Orange-Brownish Black.