• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.17-19
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• 2005

This study is for geochemical relationships between ginseng and soil from three representative soil types from Keumsan, shale, phyllite and granite. In the weathered soils(avg.), shale area is high in the most of element, but low in the granite area. In the field soils(avg.), the shale area is mainly high, but low in the granite area and comparing with ages, most of elements are high in the 2 year soils, but low in the 4 year soils. In the host rocks(avg.), high average element contents are shown in the phyllite and shale areas. In the ginsengs, differences of the element contents with ages are not clear, but show high element contents in the 2 year ginsengs of the shale and phyllite areas, and low contents in the 4 year ginsengs of the granite area. In the relative ratios(weathered soil/field soil), most of elements from the shale area are high, above 1, suggesting high element contents in the weathered soils of the shale area relative to the granite and phyllite areas. In the relative ratios(weathered soil/host rock), most of elements Ewe above 1, suggesting the high element contents in the weathered soils relative to the host rocks. Relative ratios (soil/ginseng) of the element contents are generally several times to ten times. Among the ginsengs of different ages with the same area, the relative ratios are small in the Cu and Zn contents. Regardless of the areas, big differences of the relative ratios are found in the Co and small differences are in the Cu and Zn, which suggest that differences between soils and ginsengs are big in the Co contents and small in the Cu and Zn contents. Regardless of the ages, differences among relative ratios are small in granite area relative to the shale. area, which suggest more similarity of the granite soils with ginsengsrelativetotheshalearea.

• Journal of the Korean GEO-environmental Society
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• v.5 no.1
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• pp.35-46
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• 2004

In Korea, around one - third of the country is occupied by granite, and granite weathered soils are widely distributed. Most of the research on this soil has been performed using reconstituted specimens because of the extreme difficulty of undisturbed sampling due to the sensitive particle structures. Therefore, the comparisons of deformational characteristics, which is expressed in terms of shear and Young's moduli and damping ratio, obtained from the undisturbed and reconstituted specimens are important for the reliable understanding of soil behavior. In this study, the resonant column and torsional shear tests were performed on granite weathered soils in Korea, and the deformation characteristics of undisturbed and reconstituted soil on granite weathered soils were evaluated and compared.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.45-55
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• 2012

This study is about the application of waste stone sludge as fill material. Waste stone sludge, weathered granite soil, and the mixture of the former and the latter strengthened with staple fiber are experimentally analyzed for measuring strength property. When staple fiber was mixed with waste stone sludge, weathered granite soil, and the mixture, there was a nearly linear relationship between the amount of the staple fiber and the increasing ratio of unconfined compressive strength. The increasing ratio of unconfined compressive strength was the largest in weathered granite soil. The increasing ratio of unconfined compressive strength of the mixture was similar to that of waste stone sludge. In the case of the mixture of weathered granite soil and waste stone sludge, an internal friction angle tended to increases rely on increasement of staple fiber content, whereas the change of cohesion was small. An internal friction angle was increased by 21 percent when staple fiber content is 0.75 percent. Comparing with weathered granite soil or waste stone sludge, strength parameters of the mixture were increased relatively. Thus strengthening effect of staple fiber in the mixture is expected.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.43-55
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• 1999

This study evaluated Yasufuku's constitutive model in terms of its capability to accurately consider the observed behavior of Iksan compacted weathered granite soil for various stress-paths. The strains calculated from the model are in reasonable agreement with those measured, but some discrepancies occur. The largest differences between measured and calculated strains occur for axial strain of proportional loading with increasing stress. Yasufuku's constitutive model can consider the observed behavior of Iksan compacted weathered granite soil with accuracy for conventional triaxial compression and for p'-constant loading with increasing stress ratio.

• Journal of the Korean Geosynthetics Society
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• v.6 no.3
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• pp.1-7
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• 2007

The property of weathered soil cannot but have a possibility of having a limit when its precise approaching due to the various weathering environment, and the peculiarity of its conduct affected by the weathering degree and effect factors. Especially most domestic or international researches are concentrated on the sedimentary soil, trying to analyze the mechanical behavior of weathered soil from the viewpoint of sedimentary soil. Therefore, it's difficult to judge if those results meet the actual conduct of weathered soil. This study suggested a way of weathering degree changing experiment as an early stage in an experiment of artificially changing weathering degree. In order to find out the property of strength change by the change of weathering degree, indoor mechanical experiment was made using soil sample after freezing and thawing. Under the weathering degree, characteristic change is watched by country rock and region of weathered granite soil.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.181-194
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• 1999

Both the chemical components and the physical and mechanical properties of the compacted and undisturbed weathered granite soils were estimated to investigate the influences of the degree of weathering and saturation on the shear strength. The weathered granite soils used in this study were taken from six different sites in Korea. The results showed that the shear strength of weathered granite soil decreased with increasing the degree of weathering and saturation. Under the normal stresses less that 40kPa, the shape of Mohr-Coulomb failure envelope followed curved or hyperbolic relationship and a half of cohesion value obtained by the common shear test was observed. Using the Sueoka's method, the values of CWI were ranged from 21.5 to 31.26 which can be characterized as a completely weathered granite soil. Large decrease in shear strength and remarkable variation in dilatancy were observed in saturated granite soil compared to unsaturated soil. It was also found that the shear strength of undisturbed weathered granite soil of Pungam site can be expressed approximately by the equation of ${(\tau)_{sat}= 1.0(\tau)_{unsat}-12.48}$ and this equation can be extended to the other sites considered in this study.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.743-750
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• 2002

Unsaturated soil has a possibility to induce a negative pore water pressure. Until now, saturated soil is mainly focused on the research of soil mechanics. Recently, soil mechanics is researched on two major parts such as saturated and unsaturated soil mechanics. Negative pore water pressure has a non-linear relationship with the water content changes. Soil-water characteristic curves of soil in Korea are not determined. There is no proper characteristic value such as air-entry value and residual water content. In this study, the characteristic curves of reclaimed soil, sand, and weathered granite soil were determined by laboratory tests. Air-entry value and residual water content were determined by fitting methods. Soil-water characteristic curves were estimated based on the particle-size distribution and compared with the laboratory test results. The results of soil-water characteristic curves estimation indicated that Fredlund and Wilson's model is excellent for sand and weathered granite soil. Arya and Paris's model is excellent for reclaimed soil.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2C
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• pp.69-77
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• 2012

In general, geothermal energy pile and horizontal ground heat exchangers are installed in shallower depths than conventional vertical ground coupled heat pumps. Consequently their heat exchange performance is strongly governed by thermal conductivity of soil layer. Previous studies have shown that the thermal conductivity of soil above ground water table significantly affects the heat exchange rate because of partially saturated condition in soil and consequent variation of soil thermal conductivity. This paper presents a study result on the prediction of thermal conductivity of weathered granite soils. For weathered granite soils sampled from 5 locations, thermal conductivity tests were conducted with varying porosity and degree of saturation. The existing thermal conductivity models in literatures appeared inappropriate to the weathered granite soils. Hence, an empirical equation was proposed in this paper and its validity was examined by applying it to thermal conductivity test results obtained for weathered granite soils in this study and from literatures.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.341-344
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• 2002

This study, soil sampling includes disturbed weathered granite soils from 8 different sites and disturbed weathered non-granite soils from 5 sample sites, put a purpose on finding for a utility possibility and practical use in this study. As a result of this study, internal friction angle & cohesion indicate which are from re-mold of samples by compaction seem to be able to use a compared to an field data. It is considered that strength parameter of disturbed weathered granite soil in the field is a useful reference.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.211-214
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• 2003

This study, soil sampling includes disturbed weathered granite soils from 8 different sites and disturbed weathered non-granite soils from 5 sample sites, put a purpose on finding for a utility possibility and practical use in this study. As a result of this study, internal friction angle & cohesion indicate which are from re-mold of samples by compaction seem to be able to use a compared to an field data. It is considered that strength parameter of disturbed weathered granite soil in the field is a useful reference.