• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.334-341
• /
• 2004

The coefficient of permeability is one of the most important properties in unsaturated soils. The permeability varies with change in the water content as the soil water characteristic curve(SWCC) does. Thus the permeability curve of unsaturated soils has the similar shape with the soil-water characteristic curve(SWCC). Therefore, the methodologies have been studied to simply predict the unsaturated permeability from the SWCC. In this study, the experimental tests of SWCC and permeability were carried out for domestic weathered granite soils. The SWCC test results were fitted to Fredlund and Xing's SWCC equation and then it was found that there are some relationships between the parameters of SWCC equation and the basic soil properties. Accordingly we used an ANN(artificial neural network) model to obtain the SWCC parameters from the basic soil properties. Finally, the coefficients of permeability were predicted from these results by a prediction model.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.11
• /
• pp.5-11
• /
• 2006

The purpose of this study was to examine the proper mixing ratio of ordinary portland cement and Bottom Ash to recycle the Bottom Ash, which is an industrial waste. After the evaluation, the compressive strength and durability were assessed using the mixture of completely weathered soil (Hwangto), weathered granite soil, and Bentonite. Then environmental friendliness of this mixed material was examined through heavy metal leaching method. It was found out that proper mixing ratio is 6:4, and that the 6% mixture quantity of completely weathered soil (Hwangto), weathered granite soil, and Bentonite is the most effective for compressive strength and durability It was also found out through heavy metal leaching method that the Bottom Ash could be below the standard of the Clean Water Law.

• The Journal of Engineering Geology
• /
• v.27 no.4
• /
• pp.451-462
• /
• 2017

Physical weathering caused by external forces and chemical weathering caused by the decomposition or alteration of constituent materials are the two factors that dominate the mechanical properties of rocks. In this study, a field investigation was undertaken to identify the physical and chemical weathering characteristics of the biotite granite and granitic weathered soils in Gyeongju, South Korea. Samples were collected according to their grade of weathering and subjected to modal analysis, XRD analysis, XRF analysis, physical property tests, particle size distribution tests, and slake durability tests. Modal and XRD analysis identified these rocks as biotite granite; secondary alteration minerals were not observed. Physical property tests and particle size distribution analyses indicate an average porosity of 41.28% and a sand content of > 90 wt.%. These values are somewhat higher than those of granites in general. The results of the slake durability test and XRF analyses show that the physical and chemical weathering indices of the samples vary with the degree of weathering.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.3
• /
• pp.17-25
• /
• 1999

The feasibility of using waste lime, which is produced as a byproduct during the manufacture of sodium carbonate in Inchon, Korea. as a stabilization admixture with weathered granite soil was investigated. Laboratory tests were conducted to determine the chemical composition, pH, compaction characteristics, unconfined compression strength. X-ray diffraction analysis of waste lime and weathered granite soil admixtures. Based on the present tests, it appears that the admixtures are environmentally safe and can be used as landfill material.

• Journal of the Korean Geosynthetics Society
• /
• v.16 no.2
• /
• pp.175-181
• /
• 2017

This paper presents the results of an investigation into the effect of forced temperature change cycles on physical and mechanical properties of sand and weathered granite soil. The effect of forced temperature change cycles on the particle arrangement and the thermal conductivity was first investigated. A series of triaxial compression tests on the soils were also performed to look into the effect of temperature change cycles on the stress-strain-strength behavior.

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

• The Journal of Engineering Geology
• /
• v.18 no.3
• /
• pp.311-319
• /
• 2008

Evaluation of an amplitude domain reflectometry (ADR) type soil moisture sensor as ThetaProbe ML2x using the response of frequency impedance was performed in a variety of soil porous media such as Jumunjin standard sand, weathered granite soil at Sangju area, and weathered gneiss soil at Jangsu area. The tested soils were classified with a dried condition and a wetted condition for comparing with soil volumetric water content under different installed depths of the measurement sensor. In the results the part of measurement rod including one signal rod and three shield rod 6cm in length was found to decrease the variation of measurement output voltage with insert 5cm over into the soil porous media. The measurement output voltage was verified to more stable output voltage under weathered granite soils and weathered gneiss soils contained the fine grain materials such as clay and silt minerals than the gradual grain material like as the standard sands. Therefore, measurement values by soil moisture sensor can be offered the more stable values when an contact volume between soil porous media and measurement sensor increase.

• Journal of the Korean Society for Railway
• /
• v.8 no.1
• /
• pp.57-62
• /
• 2005

The frost heaving pressure can be a problem for weakening of the railway roadbed material. This study was initiated to investigate the soils frost heaving pressure and physical characteristics(Liquid limit, permeability, SEM analysis) resulting from freezing and freezing-thawing cycle process. Therefore, upon freezing a saturated soil in a closed-system from the top, a considerable pressure was developed. Weathered granite soils, sandy soil were used in the laboratory freezing test which sometimes subjected to thermal gradients under closed-systems. The frost heaving pressure arising within the soil samples and the temperature of the samples inside were monitored with elapsed time. The degree of saturation versus heaving pressure curve is also presented for weathered granite soil and the maximum pressure is closely related to this curve. Based on the laboratory test results, fine-grained soils with strong attractive forces between soil grains md water molecules, and additional water is attracted into the pores leading to further volume changes and ice segregation.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.26 no.3
• /
• pp.81-89
• /
• 1984

To examine the moisture adsorption and permeability characteristics, weathered granite soils of different degrees of weathering, cultivated upland soils and sands of Han-river were sampled. The results are as follows: 1. In case that the mother rock was same, the pF values under same moisture content decreased according as the grain size of soil became finer by the weathering process. 2. In case that the mother rock was different, the pF value varied by the behavior of clay minerals, and the cultivated upland soils showed more sensitive reaction than sands and fresh granite soils. 3. The pF value changed by the difference of primary moisture content and also influenced by soil structure, testing method and etc. 4. The pF value and compaction curve had close relation, however under same moisture content, the pF value decreased by the increment of density. 5. The permeability depend on the available void ratio between the soil particles according to the degree of weathering, and the pF value of available void water between the soil particles which related directly to permeability was about 3.3 except the void water holded in the soil particles. 6. As the above, the pF value and permeability were differentiated by degree of weathering, primary moisture content, density and etc. Therefore it is considered unreasonable to define uniformly by soil texture.

• The Journal of Engineering Geology
• /
• v.32 no.3
• /
• pp.401-410
• /
• 2022

This work reports an oven drying test performed on weathered granite soil from Yecheon, Korea, in order to find an effective method for measuring the weight of pure soil particles. After samples were oven dried, weights measured following desiccation using the method specified by the Korean Industrial Standard (KS F) were compared with weights measured without prior desiccation. Soil samples exposed to air for 45 min after oven drying absorbed moisture from the air and gradually increased in weight. When a desiccator was used, results measured 30 s after exposure to air indicated weight increases of 0.103-0.735% (depending on the particle size of the soil) relative to equivalent samples measured without desiccation. Using a desiccator after oven drying leads to overestimation of the pure soil weight. Therefore, measuring the weight of a soil sample immediately after oven drying without using a desiccator can reduce the error of weight measurement.