• 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.

• 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.

• Proceedings of the Ginseng society Conference
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• 2008.05a
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• pp.74-75
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• 2008

This study is for geochemical relationships between ginsengs and soils from three representative soil types from Keumsan, shale, phyllite and granite. For these study, ginsengs, with the field and weathered soils were collected from the three regions, and are analysed for the major and trace elements. In the weathered soils(avg.), the granite and phyllite areas are high in the most of elements while the shale area is low. In the correlation coefficients, negative correlations are shown in the $Al_2O_3$-MgO pair while positive correlations, are shown in the Ba-Sr, Zr, Sr-Zr and Cs-Ge pairs. In the field soils(avg.), the granite and phyllite areas are, generally, high in the most of elements while the shale area is low. In the shale area, the major elements are high in the 4 year soils, but low in the 2 year soils. The LFS(Ba, Sr, Cs) and transitional elements are high in the 2 year soils, but low in the 4 year soils. The HFS(Y, Zr) is high in the 4 year soils. In the correlation coefficients, most of the elements from the 4 year show positive relationships. Positive correlations are shown in the $Al_2O_3$-CaO, MnO-MgO, V-Tl, and Ba-Sr pairs in all localities. In the ginseng contents, clear chemical differences with the ages are shown in the shale and granite ares, but not clear in the phyllite area. In the shale area Mn, Mg, Ba, Sr, and Y contents, increase with ages but decrease in Al, Cs, Be and Cd. In the correlation coefficients, degrees of the correlations for the major elements become low with the ages. Positive correlations are shown in the Al-Mn, Ti, Mn-Ti, Mg-Ca, Ca-K, Ba-Cs, Y and Cs-Y pairs. Comparisons with ginsengs of the same ages from the different areas suggest that generally, the 2 years in the shale and 3 and 4 years in the granite area are distinctive. Relative ratios(granite/ shale area) of the ginsengs are below 1 in the major elements except Mn in the 2 year ginsengs and above 1 in the other elements except Mg and Na in the 4 year. Relative ratios(granite/ phyllite area) of the ginsengs are high in the 3 year from the phyllite area. In the relative ratios(weathered/field soils) of the soils, numbers of the elements showing the ratios of above 1 increase from the shale, to phyllite and granite in the case of the major elements, but decrease in the case of the trace elements. These results suggest that major elements are high in the granite while trace elements are high in the shale area. In the relative ratios between field soils and ginsengs(field soils/ginseng), the shale area, regardless of the ages, show differences of several hundred times in the $Al_2O_3$, $TiO_2$, Y and Tl, of several ten times in the MnO, MgO and Ba and of several times in the CaO contents. These results suggest that ginseng contents are significantly different from the field soils in the $Al_2O_3$, $TiO_2$, Y and Tl, but similar in the CaO contents. The phyllite area, regardless of the ages, show differences of several hundred times in the $Al_2O_3$, $TiO_2$, Y, Tl and Be, of several ten times in the MnO, MgO, $Na_2O$ and Ba, and of several times to ten times in the CaO, $K_2O$ and Sr contents. These results suggest that ginseng contents are significantly different from those of the field soils in the $Al_2O_3$, $TiO_2$, Y, Tl and Be, but similar in the CaO, $K_2O$ and Sr contents. The granite area, regardless of the ages, show differences of several hundred times in the $Al_2O_3$, $TiO_2$, Tl and Be, of several ten times in the Ba, and of several times to ten times in the MgO and CaO contents. Of the other elements, differences of several times to ten times are shown in the MnO, $K_2O$ and Sr contents. These results suggest that ginseng contents are significantly different from those of the field soils in the $Al_2O_3$, $TiO_2$, Tl and Be, but similar in the $K_2O$ and Sr contents. Comparisons among the different ages from the same area suggest that, in the case of shale area, differences of several hundred times in the $Al_2O_3$ and $TiO_2$, of the several ten times in the MnO, MgO and Ba and several times in the CaO and $K_2O$ are shown in the 2 year ginsengs. Differences of several hundred times in the $Al_2O_3$, $TiO_2$, Cs, Y, Tl and Be, of above several ten times in the MnO, MgO, $K_2O$ and Ba, and of several times in the CaO and Sr are shown in the 3 year ginsengs. Differences of several hundred to thousand times in the $Al_2O_3$, of above several hundred times in the $TiO_2$, Cs and Y, and of several ten times in the MnO, MgO, $K_2O$ and Ba, and of several times in the $Na_2O$ are shown in the 4 year ginsengs. These relationships suggest that, regardless of the localities in the shale area, $Al_2O_3$ contents of the soils show big differences from those of the ginsengs. Regardless of the ages of ginsengs, comparisons with the overall average contents of each area show differences of several hundred times in the $Al_2O_3$, $TiO_2$, Cs and Tl and of several ten times in the MnO. These overall relationships suggest that the $Al_2O_3$, $TiO_2$, Cs and Tl contents of the soils are higher than those of the ginsengs, show big differences between two and low different contents are found in the MnO. In detail, differences of several hundred times in the Y, and ten times in the MgO and Sr, and of several times in the CaO, $Na_2O$, $K_2O$ in the case of shale area, are shown. These results suggest that the soils are higher than the ginsengs in the Y and significantly differences in Y, and moderately differences in the MgO and Sr, and low differences in the CaO, $Na_2O$ and $K_2O$ are shown between soils and ginsengs.

• Journal of Korean Society of Forest Science
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• v.54 no.1
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• pp.25-35
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• 1981

Some physical and chemical properties of forest soils in Korea were analyzed for providing the reasonable management methods of forest lands, Among 375 soil series surveyed until 1979, 93 soil series of forest soils were classified and analyzed according to their characteristics. Firstly soil data were classified into 5 categories by weathered products and secondly were classified and analyzed by parent rocks. The results are as follows: 1) In forest soils characterized by weathered products volcanic ash soils were proved to be the most fertile and alluvial soils were turned out to be the most infertile soils. Residual soils on mountain and hill were mostly on the average in all kinds of soil properties analyzed except total soil depth. 2) Igneous rocks developed rather infertile soils containing large amount of organic matter and available $P_2O_5$ with relatively deep soil depth and strong acidity. On the other hand sedimentary rocks produced rather shallow soils containing small amount of organic matter and available $P_2O_5$ but they were relatively fertile with weak acidity. 3) Among igneous rocks basalt and trachyte produced very fertile soils and granite and andesite produced slightly infertile soils. 4) Among sedimentary rocks limestone soils had high fertility neutral in acidity but low amount of available $P_2O_5$ 6) Alluvial sand produced generally very infertile soils with great soil depth comparing with the arable alluvial land with high fertility.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.608-618
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• 2001

To understand the weathering processes of the soil by submicroscopic method is very important to realize the properties of the soils. In this study soil formation processes show every steps to the changes in chemical and mechanical properties and the submicroscopic characteristics of soil weathering on the profiles of forest soils derived from granite in southern part of Korea. Fecal pellets(SEM) are given a full detail of the positive activities of the forest soil animals; mainly invertebrates in the O horizon and the E horizon. External shapes of fecal pellets have been divided into five groups : spherical, ellipsoidal, cylindrical, platy and threadlike. But doughnutlike form of fecal pellets is observed in this study. The soluble and suspended materials in the soils move downwards by percolation from the A horizon to the B or the BC horizons, and result in the illuviation cutans(SEM) on the ped surface of the lower horizon and deposited stack of kaolinite. Illuviated cutans are deposited on the ped surface even in the depth of 312cm in the BC horizon as well as the Bt horizon and comprise of fine silt, coarse clay and fine clay. A lot of halloysites are observed on the cutan surface. Halloysite formation from feldspars has been well known but a lot of hallyosite formation are observed in this study. The formation were predicted by Jackson(1962), inferred by Wada and Kakuto(1983a, b) and proved evidently by Cho and Mermut(1992a, b). This also suggests that halloysites in the soils derived from granite are formed a lot from ferruginous chlorites. The release of Fe from the chlorite structure are significant pedogenic processes and newly formed Fe oxides imparted a red color to the soils. The iron oxides particles, which are ejected and recrystalized, aggregate thickly on the edge of the ferruginous chlorites, and this indicates the release of structural Fe from weathered chlorites. Hematites and goethites are frequent in the fine clay in this soils.

• Journal of the Society of Disaster Information
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• v.16 no.3
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• pp.577-585
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• 2020

Purpose: The presence of the matric suction in unsaturated soil increases the stability of the slope, but the reduction of the matric suction due to precipitation can cause sudden slope failure, resulting in a major disaster. In this paper, engineering characteristics in unsaturated state were analyzed for granite weathering soil, which is the representative mountain soil of Korea. Method: Experiments and analysis were conducted on granulated weathering soil as unsaturated shear strength relationships for moisture characteristic curves, unsaturated injection curves, and matric suction under unsaturated conditions. Result: It was analyzed that a rapid change in the matric suction for volumetric water content occurs compared to the case where the particle size distribution is poor and the particle size distribution is good. A good case for the particle size distribution indicates a relatively small permeability coefficient at the same matric suction capacity compared to a poor case. The greater thematric suction, the greater the shear strength. Conclusion: For Korea's representative soil, granulated weathering soil, the functional characteristic curves, unsaturated permeability coefficients, unsaturated shear strength, etc., which are engineering characteristics in unsaturated state, were tested to secure each correlation.

• Journal of the Korean GEO-environmental Society
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• v.12 no.5
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• pp.5-12
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• 2011

Water content is one of the significant engineering properties of soil for predicting the behavior of soil matrix. Conventional drying oven can be widely used to obtain the values by drying the soil specimens for 16 to 24 hours at $105^{\circ}C$. Although a number of experimental data has been accumulated for the conventional method of drying soil for water contents, shortcomings of the method are still hard to overcome such as long drying time for in situ use and the difficulty of taking prompt actions against emergency cases. Recently, ASTM and JGS have established microwave oven drying techniques for obtaining water contents to cope with those problems. And the reliability evaluation study has been also performed on the microwave oven drying for water contents. Feasibility study of the microwave oven drying was performed to confirm the process of the technique with Jumunjin sand, kaolinite, bentonite, weathered granite soil, and organic soil. Investigation was also conducted on the factors affecting and enhancing the reliability of the technique.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.43-71
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• 1999

This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.11-21
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• 2015

The method to replace asphalt and cement is needed to reduce the carbon emission on road. Polymeric material which is light and easy to handle while having complex function with less carbon emission would be highly effective when it replaced soil pavement containing cement. This study is intended to identify the usability of soil pavement containing organic solidification agent only through the field test. Pavement on bike trail still satisfied required bearing capacity coefficient in 3 months. Pavement after passing 1.6 bil units of bike through pavement acceleration test that simulated a long-term serviceability during a short-time still remained unaffected, demonstrating a long-term serviceability of soil pavement.

• Journal of the Korean Geosynthetics Society
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• v.14 no.3
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• pp.43-51
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• 2015

In seasonal frozen areas which have a temperature difference in the winter and spring season like south korea, if stiffness reduction by repeated freezing and thawing occurs to slopes adjacent to private facilities or mountain slopes, safety factor is insufficient to design criteria and landslide could be occurs due to rainfall or snowfall. It can lead to large damage of human life and property. In this study, in order to examine the safety changes of mountain slopes by repeated freezing and thawing, soil samples series of SP and SM by USCS distributed in surface soil of mountain slopes were collected for specimens. Through the direct shear test, the characterestics of frozen soil shear strength were analyzed and by utilizing numerical methods, chracteristics of strength reduction of weathered granite soil according to repeated action of freezing and thawing, changes in the stability of the slopes when applying freezing and thawing of the soil samples were examined. As a result, the maximum shear stress decreased approximately 10%, and slope stability analysis confirmed that required safety factor is less than compare with the non-frozen samples.