• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.86-100
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• 1985

In order to investigate the strength characteristics of weathered granite soils in unsaturated state, the five physically different weathered granite soils and the common soil (sandy loam) were examined. The disturbed and the undisturbed material were prepared for triaxial compression test. The following conclusions were drawn from the study; 1. Dry density of the undisturbed soil samples was lower than maximum dry density determined from the compaction test and it showed the higher value at the well graded soil. 2. The failure strength of the samples decreased with the increase of moisture content of the soil and these results were highly pronounced at the common soil sample having a good cohesive property. 3. On weathered granite soils, the cohesion was lower measured and the internal friction angle highly, the decrease rate at internal friction angle with increase of moisture content of the soil was more significant than that of cohesion 4. The modulus of deformation of the samples decreased with increase of moisture content of the soil and these phenomena were highly pronounced at the weathered granite soils than common soil. 5. The failure strength of the samples increased with in crease of confining pressure and effect of confining pressure on failure strength was highly significant at the lower moisture content of the soil.

• Journal of the Korean Geotechnical Society
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• v.23 no.11
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• pp.59-66
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• 2007

In order to clarify the influence of gravel content on the mechanical properties of gravel-mixed decompose granite soils, large-scale one-dimensional compression tests were performed. The sample used in the study was a decomposed granite soil from Shimonoseki in Yamaguchi prefecture in Japan. After adjusting the grain size of the said soils, the specimen compacted with a certain level of compaction energy was put to the test. Based on the results obtained, when gravel-mixed decomposed granite soil was compacted at the same energy level, there existed the specific gravel content at which dry density was maximum and which also produced the minimum compression index. Furthermore, from these results, an expression based on a two-phase mixture theory was proposed to quantitatively evaluate the effects of gravel content and initial dry density and the material parameters calculated through the proposed method proved to exactly estimate the actual measuring value.

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.4
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• pp.53-59
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• 1981

This experiment was carried out to find out the effectiveness of soil cement stabilization about the Song-I in Cheju province. The results are summarized as follows; 1.The increasing ratio of unconfined compressive strength according to the increment of cement content was markedly low compared with the weathered granite soil, so the effect of stabilization was low. 2.The moisture content of the sample of Song-I indicates the maximum unconfined compressive strength showed at the 5% or so of dry side than the optimum moisture content and the change of the unconfined compressive strength according to the change of moisture content was not sensitive compared with the weathered granite soil. 3.Generally the primary strength of curing age within 7 days of the sulfate resisting cement was low compared with the normal portland cement and the strength of 28 curing days showed a similar tendency, especially in case of Song-I, and it seemed that the sulfate resisting cement was a little more effective than the normal portland cement. 4.As the unconfined compressive strength of grain size controlled Song-I was low compared with the weathered granite soil, so the rate of weight loss by the durability test was great, therefore it was thought that the durability was weak.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.152-157
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• 2005

This experimental study was devoted to investigate skin friction of H group piles with uplift loading conditions in granite soil under laboratory test. Model piles made of steel embedded in weathered granite soil were used in this study. Pile arrangements($2{\times}2,\;3{\times}3$), pile space(2D, 4D, 6D), and soil density($D_r=40%,\;80%$) were tested. The main results obtained from the model tests can be summarized as follows. The series of tests found that ultimate uplift load and displacement for group piles were increased as piles space ratio increases to $D_r=40%$ of soil density. In the relative density of $D_r=80%$, bearing capacity for group piles was greater than for single pile. In the relative density of $D_r=40%$, the theoretical value of skin friction for group piles was greater than practical value. In the relative density of $D_r=80%$, both theoretical and practical value of skin friction for group piles were increased as piles space ratio increases.

• Geomechanics and Engineering
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• v.25 no.2
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• pp.75-87
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• 2021

Because the hydraulic/mechanical behaviour of unsaturated soil is more complicated than that of saturated soil, one of the most important issues in modelling unsaturated soil is to properly couple its stress-strain relationship with its water retention characteristics. Based on the results of a series of tests, the stress-strain relationship and the changes in suction and saturation of unsaturated completely decomposed granite (CDG, also called Masado) vary substantially under different loading/hydraulic conditions. To precisely model the hydraulic/mechanical behaviour of unsaturated Masado, in this study, the superloading concept was firstly introduced into an existing saturated/unsaturated constitutive model to consider the structural influences. Then a water retention curve (WRC) model considering the volumetric change in the soil, in which the skeleton and scanning curves of the water retention characteristics were assumed to shift in parallel in accordance with the change in the void ratio, was proposed. The proposed WRC model was incorporated into the constitutive model, and the validity of the newly proposed model was verified using the results of tests conducted on unsaturated Masado, including water retention, oedometer and triaxial tests. The accuracy of the proposed model in describing the stress-strain relationship and the variations in suction and saturation of unsaturated Masado is satisfactory.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.3
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• pp.93-100
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• 2015

The object of this paper is to study the shear characteristics of the weathered granite soil. To this end, a series of consolidated undrained triaxial compression tests are carried out to investigate the shear parameters-cohesion and internal friction angle-for the degree of saturation and degree of weathering. From the results, it is found that the shear parameters of weathered granite soil are influenced on the degree of saturation, degree of weathering and disturbance. Especially, internal friction angle is more influenced on the upper factors than cohesion. And shear parameters are more acted on the degree of saturation than the degree of weathering in the test range. It is, therefore, recommended that must be considered the conditions of granite soil-degree of saturation, degree of weathering and disturbance etc-in case of the calculation of bearing capacity, stability analysis and other designs with shear parameters.

• Geotechnical Engineering
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• v.7 no.3
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• pp.33-42
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• 1991

Increasing demand of rational analysis of dynamic soil behavior subjected to repetitive loading has evolved soil dynamics which is essential for proper design and/or analysis of dynamically loaded soil structure. In this paper, the stress-strain behavior of weathered granite soil under cyclic loading is stud- ied by measuring the strength and the strain before and after application of at least 11, 000 cycles of repetitive load. Relationships are suggested for predicting results of soil dynamics from those of soil statics.

• Journal of the Korean GEO-environmental Society
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• v.7 no.6
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• pp.45-56
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• 2006

Recently, the more potential waste sites are being required as increasing the demand of better human life. But the construction of waste disposals has many restrictions because of lack of good quality clay and high cost of liners. So, in this study, we studied the liner materials to develop more cheaper soil liner that can be satisfied the environmental criterion for the coefficient of permeability and shear strength. A series of compaction test and triaxial (consolidation, permeability, and shear) tests were performed to obtain the optimized weight ratio of Bentonite-Soil mixture (B/S) including the least amount of bentonite. A series of soil tests were performed to acquire the appropriate weathered granite soil-bentonite mixture that is satisfied the environmental criterion of soil liner($k=1{\times}10^{-7}cm/sec$). At first, weathered granite soils were classified with four different particle-size soils, and B/S ratio was increased as 5% step for each particle-size. The test results showed that in case of weathered granite soil passing through No. 100 sieve, B/S=15% satisfied the soil liner criterion. The measured coefficient of permeability and the Chapuis's two equations were also compared. And a predicting equation for the coefficient of permeability was suggested, which is suitable for the mixture soil with the B/S ratio used in this study. The optimal weight ratio for the mixture soils used in this study was 15% in the both cases of permeability and shear strength.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.200-202
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• 2002

This study was for comparisons of transitional element concentrations from the two different soil, serpentinite(SP) and granite area(GR), Kwangcheon and Hongseong area. Soils were collected by soil depths (10, 20 and 30cm) from the sites selected In the plant species(coniferous and deciduous species). In the soils, the SP was high in the Cr, Mn, Fe, Co, Ni and Zn concentrations, while the GR was high in the Cu, As, Sc and V. With the soil depths, the elements had high solubility, such as Cr, Co and Ni concentrations, were high in the SP, while the other elements were not clear. For the both species, the SP was high in the root and bolebark, while in the GR, not clear. Coniferous species in the same soil types, was higher than the deciduous In most elements. The more with increasing ages, the more with element accumulation in most plant parts except leaves. Comparisons between the soils and plant species, in the case of the element contents within the soils, the plant species in the same sites was similar trend. especially, clear in the SP

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.329-336
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• 2002

The earth structures and in-ground LNG tank, and buildings can be constructed with using artificial freezing method on the reclaimed land. In this study, upon freezing a saturated soil in a closed-system from the top, a considerable pressure was developed. The pressure is the result of the surface energy of a curved ice-water interface. The most significant of these parameters will have the greatest effect on the classification. In order to establish frost-susceptibility criteria based on frost heaving expansion pressure, more soils have to be tested. This study was initiated to investigate the soils frost heaving expansion pressure and moisture characteristics resulting from freezing and freezing-thawing cycle process. Weathered granite soils, sandy soil, sandy soil were used in the laboratory freezing test subjected to thermal gradients under closed- systems.