• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.3
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• pp.13-20
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• 2005

This study was conducted to suggest the ecological restoration methods of the decomposed granite cut-slope by organic soil amendment materials. Field test carried out for the cut-slope with organic soil amendment materials method and other three revegetation methods in Cheongwon. Test revegetation plants were Festuca arundinacea, Lolium perenne, Dactylis glomerata, Lespedeza cyrtobotrya, and Arundinella hirta. The result of this study can be summarized as follows; 1. The soil hardness, the soil acidity, and the soil humidity of organic soil amendment materials method were at a suitable value for plants growth. And it was better as compared with other three revegetation methods of cutting-rock slopes. 2. The result of toxic substance investigation, all items were at a suitable for standard law. 3. During one year after seeding, most plants germinated and especially Festuca arundinacea and Dactylis glomerata grows well. Seedling numbers were 336.7 per $m^2$(after 6 months), 183.3 per $m^2$(after 10 months), and 353.3 per $m^2$(after 6 months). Ten months later after seeding, plants showed 80% ground coverage. Visual rate, plant height, and growth rate were excellence, Also, high plant growth in spring better than autumn.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.1
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• pp.116-124
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• 2002

Natural resources fur the construction materials such as good soil, sand, and coarse aggregates have been encountered to be short due to excessive use by human. Even though some soil has been found to be unsuitable for construction materials, soil with reinforcement can naturally be an answer to these alternatives. According to recently published papers on fiber mixed soil, fiber mixed with soil can improve shear strength, compressive strength and post-peak load strength retention. In this study, a series of tests were performed to clarify the characteristics of fiber mixed soil and to give basic data for design and construction and their engineering properties, that is, unconfined compressive strength, splitting tensile strength, shear strength, crack by drying, freeze-thaw, creep and Poisson\`s ratio, were investigated and analyzed. It has been shown that fiber mixed soil is one of good alternatives fur the civil and building construction materials.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.1
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• pp.102-105
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• 2001

This study has been done to investigate the characteristics of the wall materials of a earthen house ; the core-wall of a wood-frame house and the mud-wall of a all-wall house. A series of tests is carried out to study the physical properties of wall materials which are picked from existing earthen houses. The core-wall materials are composed of sandy soil or clayey soil with low plasticity. The mud-wall materials are sandy soil with well compaction effect. It is confirmed that the wall materials are common soils which are easily picked from the residential quarter.

• Journal of Soil and Groundwater Environment
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• v.18 no.5
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• pp.15-25
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• 2013

In this study, two kinds of soil-based proficiency testing materials (PTMs), NICE-012L and NICE-012R were prepared and certified for Benzen, Toluene, Etylbenzene and Xylene with evaluation of uncertainties. In order to analyse BTEX (Benzen Toluene Etylbenzene Xylene) for the candidate materials, GC/MS was used after pretreatment according to methods of soil analysis by Ministry of Environment. For the homogeneity test among bottles in terms of candidate materials, ISO 13528 and IUPAC Protocol were used and according to the result, both candidate materials showed sufficient homogeneity. Also, the stability test over the candidate materials was accessed according to the ISO Guide 35 by classifying short-term and long-term stability and the result showed that both candidate materials showed decent stability. The reference values of the two candidate materials depending on BTEX components were derived from the average of the 11 samples that were used for verification of the samples' homogeneity. Uncertainty of measurement was combined by uchar that was caused by a characteristic value, $u_{bb}$ that was caused by between-bottle homogeneity, and $u_{stab}$ that was caused by stability, and then combined uncertainty ($u_{PTM}$) was multiplied to the coverage factor (k) derived from the effective degree of freedom from each factor that leads to expanded uncertainty (U) in about 95% of confidence level. The proficiency testing materials developed through this study were supplied to National Institute of Environmental Research (NIER) and utilized as an external proficiency testing materials for evaluating analysis capacity of soil agencies with specialty in terms of soil analysis approved by Minister of Environment.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.1
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• pp.12-20
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• 2017

Various types of organic materials could affect differently immobilization of cadmium (Cd) and its uptake by plant grown in soil. Therefore, this study was conducted to evaluate effect of different organic materials in reducing Cd phytoextractability in contaminated arable soil. To do this, rice straw and composted manure were selected as organic materials and applied at the rate of 0, 15, 30, and $45Mg\;ha^{-1}$ in Cd contaminated arable soil with $6.5mg\;kg^{-1}$ of total Cd. Radish (Raphanus sativa L.) was seeded and grown for 50 days to evaluate Cd phytoavailability with different organic materials. Composted manure was more effective to decrease $1M\;NH_4OAc$ extractable Cd concentration and increase pH of soil than rice straw. $One\;M\;NH_4OAc$ extractable Cd concentration significantly decreased with increasing application rate of composted manure. Tendency of Cd uptake by radish plant with application of different organic materials was similar to that of $1M\;NH_4OAc$ extractable Cd concentration and soil pH. Changes of soil pH with application of straw and composted might be one of factors to determine extractability and phytoavailability of Cd in this study. Radish yield significantly increased with up to $45Mg\;ha^{-1}$ of composted manure application but did not with straw application. In the view point of Cd phytoextractability and plant productivity, it is recommended to apply composted manure rather than straw in Cd contaminated arable soil.

• Geomechanics and Engineering
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• v.33 no.3
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• pp.301-315
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• 2023

Adopting cohesive soil as geocell-pocket infill materials is not fully accepted by researchers in the field of road engineering. The cohesion that may inhibit the lateral limitation of geocells is a common vital idea that exists within every researcher. However, the influence of infill materials' cohesion on geocell-reinforced performance is still not thoroughly determined. The mechanism behind this still needs to be studied in depth. This study initially discussed the relationship between subgrade bearing capacity, geocells' contribution to reinforced performance, and infill materials' cohesion (IMC). A law was proposed that adopting the soil with high cohesion as infill materials benefited the subgrade bearing capacity, but this was attributed to the superior mechanical properties of infill materials rather than geocells' contribution. Moreover, the vertical and lateral deformation of subgrade, coupling shear stress and confining stress of geocells, and deformation of geocells were deeply studied to analyze the mechanism that high cohesion can inhibit the geocells' contribution. The results indicate that the infill materials with high cohesion result in the total displacement of the subgrade toward to deeper depth, not the lateral direction. These responses decrease the vertical coupling shear stress, confining stress, and normal displacement of geocell walls, which weaken the lateral limitation of geocells.

• Advances in nano research
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• v.17 no.2
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• pp.125-136
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• 2024

In the present research the durability and geotechnical properties of an expensive clayey soil stabilized by two different compositions of additives were investigated and compared. The first composition consisted of environmentally and ecofriendly materials: BOF steel slag ranging from 0-20% as well as rice husk ash (RHA) ranged 0-16%wt of dry soil. The other composition consisted of relatively new generation of materials including nanomaterials: nano-CaCO3 as well as nano-SiO2. Atterberg limits test, free swell percent test, swelling pressure test and unconfined compressive test were used to assess the stabilizers influences upon expansive soil geotechnical characteristics. Also, the recurrent wet-dry cycles test was exerted on experimental and non-experimental samples for estimating stabilizers effects on durability. According to the results, each of the BOF slag and RHA enhances the expansive soil properties individually, while combination of slag-RHA led to better improvement of the soil properties. Also, the composition of nano-CaCO3 and SiO2 dramatically improved the clay soil operation. The optimum values of slag+RHA were suggested as 20% slag+12% RHA to enhance percent of swelling, pressure of swelling in addition to UCS as much as 95%, 96%, and 370%, respectively. The optimum value for the second stabilizer in this study was found to be 2%nano-SiO2+2% nano-CaCO3 which led to 318% increase in UCS and 86% decrease in swelling pressure.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.236-245
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• 2000

The feasibility of precision farming for small sized fields was studied by determining fertilizing amount of nitrogenous and calcareous to a cite specific region. A detailed soil survey at three experimental fields of 672㎡, 300㎡ and 140㎡ revealed a considerable spatial variation of the pH and organic matter(OM) levels. Soil organic matter was measured using Walkley-Black method and soil pH was measured with a pH sensor. Soil sample was obtained by Grid Node Sampling Method. The soil sampling depth was 10 - 20 cm from the soil surface. To display soil nutrient variation, a soil map was made using Geographic Information System (GIS) software. In soil mapping, soil data between nodes was interpolated using Inverse Distance Weighting (IDW) method. The variation was about 1 - 1.8 in pH value and 1.4 -7 % in OM content. Fertilizing Amount of nitrogenous and calcareous was determined by the fertilizing equation which was proposed by National Institute of Agricultural Science and Technology.(NIAST). The variation of fertilizing amount was about 3 - 11 kg/10a in nitrogenous and 70 - 140 kg/10a in calcareous. The results showed a feasibility of precision fertilizing for small size fields.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.299-307
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• 2009

New lake dike in Saemanguem area is 125km length and require a great amount of fill materials, but it's difficult to get the amount of materials and develop a quarry because of environment conservation. Therefore, the solution is to use the dredged soil in project area as the fill materials not to develop quarry. However, characteristic of dredged soil as a silty fined sand is very weak at seepage, sliding, erosion of dike due to infiltration of rainfall, wind etc. So, lake dike using dredged soil must be constructed safely against the unstable problem of dredged sand. The objective of research is to make safe lake dike using dereged soil on construction of Saemangeum new lake dike. So, we analyzed the characteristic of dredged soil and suggested a standard section of lake dike.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.179-186
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• 2014

Weathering indexes of the typical pedons derived from different parent materials of the soils of Korea were calculated by Kronberg and Nesbitt (1981) to understand weathering degree of the soils which might give a clue of soil formation and characterizing a soil pedon. The weathering index W1 was chemical change index, and the weathering index W2 was silicate dominant index. The chemical compositions of the 49 typic pedons were extracted from the Taxonomical Classification of Korean Soils (NIAST, 1999). The weathering indexes of Kimhae series, derived from fluvio marine material, were the highest among the analyzed soils. Within parent materials, the weathering indexes of the soils derived from limestones parent materials were high, and those derived from phorphyry materials were low. The relationship between W1 and W2 showed unique pattern which implied certain sequence within the same parent materials.