• 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 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.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.3
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• pp.70-80
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• 1989

In this research program special triaxial compression tests and dehydration-swelling tests under the condition of freeze-thaw process were conducted to show the effects of freezethaw process on the physical properties of weathered granite soil, and their results as follows; 1.Consolidation settlement of weathered granite soil mass was increased due to freeze-thaw process, and the initial tangent coefficient of dense state was higher than that of loose state. 2.Compression behaviour of soil was increased according to the decrease of freezing temperature, and when the freezing temperature was reached under - 10$^{\circ}$C, the compression rate was not influenced by change of freezing temperature. 3.The experiments showed that the void ratio and permeability of soil were converged into their values of shrinkage limit, and the permeability was higher due to the freeze-thaw process and as the lower the freezing temperature. 4.The decrease of liquid limit was indicated as the lower the freezing temperature, and as more the freeze4haw cycles, the moisture content was shown the lower side. 5.It was shown that the shrinkage was decreased by freeze-thaw process and not influenced by way of freezing temperature, but dehydration rate was higher.

• Geotechnical Engineering
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• v.13 no.6
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• pp.13-24
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• 1997

In Korea, granite is abundant and occupies around two-thirds of the country's ground. Bven though weathered granite residual soils are widely distributed, undisturbed sampling of this soil is extremely difficult because of the particultate structure. This difficulty has kept away the researchers from investigating !he deformational characteristics of weathered granite residual soil. Thus, a special undisturbed sampling device was developed and undisturbed samples were prepared for triaxial compression (TX), resonant column(RC), and torsional shear (75) tests. Local deformation transducer (LDT) was fabricated for internal strain measurements during TX tests. Both undisturbed samples and statically compacted samples of same density were tested by using TX with LDT, RC, and 75 test equipments. The behaviour of statically compacted specimens was almost the same as that of undisturbed samples in the strain ranges below 1 percent. The stiffness and strength decreased with increasing degree of weathering. In case of undisturbed specimens, strains at failure are widely varied from 2 percent to 11 percent, and planes of failure are irrelevant to the angle of internal friction due to the inhomogeneous nature.

• Journal of the Korean Geosynthetics Society
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• v.15 no.3
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• pp.1-12
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• 2016

In this study, the impact of sand and weathered granite soil is analyzed by changing the internal temperature from $20^{\circ}C{\sim}70^{\circ}C$C by installing a heating coil inside the triaxial cell. To check the effect on weathered granite soil due to increase of temperature and number of heating-coiling cycles are analyzed by measuring the temperature by using thermometer installed inside the triaxial cell and due to that deviator stress also occurred during the consolidated undrained test. To analyze the effect of weathered granite soil with change of temperature during undrained testing. The deviator stress and pore pressure is measured. As a result, pore pressure increases and the deviator stress decreases with rise of temperature.

• The Journal of Engineering Geology
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• v.13 no.3
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• pp.335-344
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• 2003

This study is focused to the physical and shear strength properties of the weathered limestone soils distributed in Changsung and Hwasun area, Chonnam province. Disturbed soil was used as soil samples. To grasp the physical and shear strength properties of weathered limestone soil, specific gravity test, atterberg limit, grain size distribution and direct shear test were conducted in the laboratory. The physical and shear strength properties of the weathered limestone soil in the study areas are as follows. The range of specific gravity (Gs) is 2.78 to 2.80, liquid limits (LL) 37 to 38 (%), plasticity index (PI) 13.7 to 15.4, and soil classification CL. The range of strength parameters by direct shear test (vd, $1.5t/\textrm{m}^3$) is 3.07 to 4.4 ($t/\textrm{m}^2$) of cohesion and 34.8 to $42.4^{\circ}$ of internal friction angle in unsaturated soils. As a result of comparing with the weathered granite soils (Yang, 1997: Mun, 1998: Park, 1998), it is considered that physical properties of the weathered limestone soils in this study are different from the weathered granite soils. On the other hand, internal friction angle of shear parameters is found to be similar.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.41-49
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• 2003

Rainfall-induced landslides in a weathered granite soil slope usually happen on shallow slip surfaces above the groundwater table. The pore-water pressure of soil above the groundwater table is usually negative. This negative pore-water pressure (or matric suction) has been found to make a large contribution to the slope stability. Therefore, the variation of in-situ matric suction profiles with time elapse in a soil slope should be understood. In this study, a field measurement program was carried out from June to August, 2001 in order to monitor in-situ matric suctions and volumetric water contents in a weathered granite soil slope. Finite-element transient seepage analyses are also conducted using SEEP/W. The influence of climatic conditions on the variation of in-situ matric suctions could be found to decrease rapidly with the change of depth. It could be found that decrement of matric suction induced by precipitation is affected not only by the amount and duration of rainfalls but also by the initial matric suction just prior to rainstorms. The soil-water characteristic from the field monitoring tends toward the wetting path of SWCC obtained from the laboratory test.

• Advances in concrete construction
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• v.9 no.6
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• pp.537-545
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• 2020

In order to reduce the usage of cement slurry in grouting engineering and consume the tunnel excavation waste soil, a new geopolymeric grouting material (GGM) was prepared by combine completely weathered granite (CWG) and blast-furnace slag (BFS), which can be applied to in-situ grouting treatment of completely weathered granite strata. The results showed CWG could participate in the geopolymerization process, and GGM slurry has the characteristics of short setting time, high flowability, low viscosity, high stone rate and high mechanical strength, and a design method of grouting pressure based on viscosity evolution was proposed. By adjusted the content of completely weathered granite and alkali activator concentration, the setting time of GGM were ranged from 5 to 30 minutes, the flowability was more than 23.5 cm, the stone rate was higher than 90%, the compressive strength of 28 days were 7.8-16.9 MPa, the porosity were below 30%. This provides a novel grouting treatment and utilizing excavated soil of tunnels in the similar strata.

• 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.

• Tunnel and Underground Space
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• v.5 no.4
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• pp.336-346
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• 1995

Geotechnical Information System (GTIS) for efficient management of three dimensional borehole data has been developed. Some problems were raised during the input process of borehole data, and alternative solutions were sought. According to the previous geotechnical reports, there is no unified weathering classification scheme. A criterion, 100 times/30cm from SPT, was turned out inappropriate to the discrimination of weathered rock from weathered soil. It has also been suggested that weathered soil, weathered rock, soft rock, and hard rock should be defined as CW, HW, MW, and SW~fresh condition. For better comparison of RQD, the use of NX size coring is recommended for the whole area although BX size coring has been used in excavated area. The limit of drilling depth up to 1 m from the top of surface of hard rock should be extended to avoid possible wrong interpretation of rock head due to the existence of corestone. The input data were analysed by geostatistical methods. It is found that the range in semivariogram is about 300m, and the variance of gneiss is greater than that of granite. It is because the granite data analysed came from almost single uniform rock mass(i.e.Seoul granite), but gneiss data came from the rock mass(i.e. Gyeonggi gneiss complex experienced several metamorphic metamorphic processes.