• The Journal of Engineering Geology
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• v.11 no.1
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• pp.101-113
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• 2001

Structural and geological engineering properties of the rock mass distributed in the Yokmang mountain area were investigated to detenninc the usable cut-out volume and quarrying efficiency. The study area is located in the southern tip of the Yangsan fault system which controls the geological structure of the Kvungsang basin. As a result, the study area is mainly composed of andesicic. rhyolitic. and granitic rocks of the Cretaceous Kyungsang Supergroup and a series of right-handed strike-slip faults is developed along NNE-SSW direction. These regional faults significantly affect the spatial and meclwnical characteristics of joints such as spacing, frequency, and compressive strength. The joint frequency is highest along the fault zones and decreases toward the remote region. Based on the geological information obtained from the field survey, the detailed structure of the Yokmang mountain was analyzed and the volume of the rock mass was assessed. Considering the minimum rock block size required for the construction of a coastal dumping site, potential cut-out volume is then estimated to be 4,018,000m$^3$ the volume % of which is 48% of Yokmang mountain including the soil and weathered rock and 61% of the unweathered rock mass.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1506-1512
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• 2010

In this study, model tests were performed to investigate the settlement characteristics of the rock/soil mixture subgrade with the many portion of mudstone due to the cyclic train loading in high-speed railway. Specially, from the tests varying initial degree of saturation, effects of increment of the degree of saturation in the subgrade due to rainfall or elevation of ground water table under cyclic train loading on the deformation characteristics were analyzed. From the results, in the low degree of saturation, settlement converged to some value. However, in the condition of degree of saturation larger than some value, settlement rapidly increased. Therefore, it was found that it is important to maintain the degree of saturation of subgrade below the specific level to prevent the settlement of subgrade.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.2
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• pp.58-68
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• 1999

This study was carried out to verify the distribution patterns of Salix gracilistyla and Phragmites japonica communities known as obligatory riparian species according to physical factors such as micro-landforms, substrates, etc., at Soo-ip stream corridor. Firstly four vegetation types - Salix gracilistyla dominant type, Phragmites japonica dominant type, mixed type of two species, and mixed type of two species to other species, were classified by cluster analysis based on UPGMA-Euclidean distance. Also these vegetation types showed many different distribution patterns in response to the longitudinal and lateral view along the stream corridor and substrate composition. Salix gracilistyla was major component of dominant vegetation types developed at attack point of bending reach and on substrates composed of rock fragments, but contrastly Phragmites japonica was most important component of dominant vegetation types at point bar of bending reach and floodplain, and on substrates composed of soil materials. Secondly the species and environment biplot form CCA strongly supported the vegetation types divided by classification. Namely Salix gracilistyla was closely correlated with rock fragments and steep slope, which is resistant to physical action even though located near running water. But Phragmites japonica showed a high correlation with soil particles sedimented at floodplain by divergent flow.

• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.143-149
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• 2011

In order to figure out the characteristics of radionuclides concentrations of nine provinces, we analyzed uranium and radon in 681 samples of groundwater. Most of uranium concentrations in each province were less than $10{\mu}g/L$, and Gyeongnam, Jeonnam, Jeju provinces did not have groundwaters exceeding the US EPA drinking water MCL ($30{\mu}g/L$) of uranium. The ratio of radon values exceeding US EPA drinking water AMCL (4,000 pCi/L) was 22.6% (154/681) and Gyeongnam and Jeju provinces had no groundwaters exceeding the AMCL (alternative maximum contaminant level). Uranium and radon concentrations in groundwaters of Gyeonggi, Chungbuk, Jeonbuk, Chungnam mainly composed of the Mesozoic granite and the Precambrian gneiss were relatively high, but the concentrations of Gyeongnam and Jeju widely comprised of the sedimentary rock and the volcanic rock were relatively low. A week correlation between uranium and radon values showed in Gangwon, Chungbuk, Gyeonggi provinces.

• 기술발표회
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• s.2006
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• pp.86-100
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• 2006

The single drilled shaft foundation has been used in the other countries, but has not used in South Korea at all This foundation is very effective and economic method in South Korea which is easy to meet a good rock mass within 50m depth from the ground We have many experiences to construct 1.52 5m drilled shaft foundations and ability to construct 30m drilled shaft foundation without special efforts The soil behavior is nonlinear, but it can be proposed in linear in practical purpose on bridges. The elastic modulus of soil can be rationally obtained by the method of Road Bridge Design Manual in South Korea using the Schmertmann(1970)'s proposal, and the elastic modulus of rock can be obtained by the field test. In seismic design the column and drilled shaft must be restricted to the elastic design because the behavior of this foundation is flexible and the arrangement of the rebars makes the various defect In this paper the design criteria is compared with FHWA design criteria, and the design criteria is proposed in consistent with Road Bridge Design Manual in South Korea. The single drilled shaft foundation of a test bridge was constructed in the Iksan-Jangsoo highway, and we checked its stability, workability and economy

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.660-670
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• 2009

Neighboring construction becomes mainstream of Ground excavation in downtown area. This causes the displacement, deformation, stress condition, etc of the ground surroundings. Therefore Neighboring construction have an effect on Neighboring structure. All these years a lot of Neighboring construction carried out, and the accumulation of technology also get accomplished. But earth retaining structure collapse happens yet. Types of earth retaining structure collapse are 12. 1. Failure of anchor or strut system, 2. Insufficiency of penetration, 3. H-pile Failure on excessive bending moment, 4. Slope sliding failure, 5. Excessive settlement of the back, 6. Deflection of H-pile, 7. Joint failure of coupled H-pile, 8. Rock failure when H-pile penetration is rock mass, 9. Plane arrangement of support systems are mechanically weak, 10. Boiling, 11. Heaving, 12. Over excavation. But field collapses are difficult for classification according to the type, because collapse process are complex with various types. When we consider the 12 collapse field, insufficient recognition of ground condition is 4 case. Thorough construction management prevents from fault construction. For limitations of soil survey, It is difficult to estimate ground condition exactly. Therefore, it should estimate the safety of earth retaining system, plan for necessary reinforcement, according to measurement and observation continuously.

• Tunnel and Underground Space
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• v.16 no.3 s.62
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• pp.232-240
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• 2006

In this paper, the blasting load has been calculated using Input Identification method and measured data in borehole blasting to reflect the exact blast behavior and soil vibration. The fitness of calculated blasting load is examined by comparing measured data and results of numerical analysis. According to the results, blasting load estimated by Input Identification method was more adequate than proposed blasting pressure equation in the reflection of blast behavior and soil vibration. In addition, it showed more reasonable results at the evaluation of structure's vibration in the 3D finite element method.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.2
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• pp.47-59
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• 2023

This study investigated and analyzed the effects of vegetation on the roadside slopes at the expressway construction sites in order to evaluate the vegetation recovery regarding soil type and revegetation technique. We selected two study sites with an area of 1,000 m² located in the construction sites of the Korea Expressway Corporation, named Hwado-Yangpyeong Expressway Section 3 and Saemangeum-Jeonju Expressway Section 7. The revegetation was monitored in three plot groups (earth, soft rock, and hard rock slopes), and scored based on the guideline of the Ministry of Land, Transport and Maritime Affairs. The revegatation was generally lower in the Hwado-Yangpyeong site than that of the Saemangeum-Jeonju site. The field monitoring indicated that the revegetation varied with slope aspect and environmental characteristics between plots. the Saemangeum-Jeonju site showed a high overall evaluation score, but there was a slight difference in the score for each plot. This seems to be due to the differences in geographical conditions, construction methods, and site environment between two sites. This study can provide basic information to understand the short-term effects of revegetation techniques in the roadside slopes.

• Journal of the Korean GEO-environmental Society
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• v.4 no.4
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• pp.45-51
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• 2003

Grouting materials in rock is grouted as vein type along the fault surface by the other way for soil and allow a change of characteristics in rock faults as a result of that. Therefore the deformation characteristics of rock faults after grouting differ as a direction and characteristic of grouted fault and stress condition of field rock. Thereby it must be analyzed the effect for deformation of rock according to characteristics of rock faults and characteristics of grouting materials to accurately evaluate the reinforced effect by grouting. But grouting method used in field until present depends on experience of workers, and inspection for those effects are evaluated by measurement of elastic wave velocity, permeability tests and etc. in field. In this study, it was investigated that the effects for shear characteristics of maximum shear strength, residual shear strength and etc. by comparison and analysis of test results which were worked by direct shear tests of rock faults with changing a type of grouting materials and the grouting depth(t) for average width(a) of fault surface roughness when OPC(Ordinary Portland Cement) and Micro cement was grouted in fault surface of field rock to evaluate characteristicsof the shear deformation for rock fault surface of dam by grouting.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.87-96
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• 2014

The objectives of this study were to characterize the physicochemical properties and mineralogy of Hwangto (yellow residual soils) from the southwestern part of Korea and to understand the soil-forming processes of the residual soils from their parent rocks. Both the yellowish residual soils as well as the unweathered and weathered parent rocks were obtained from Jangdong-ri, Donggang-myun, Naju, Jeollanam-do, Korea. The soil samples were examined to analyze the said soil's physicochemical properties such as color, pH, and particle size distribution. A scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis were performed in order to understand the mineralogy, chemical composition, and morphology of the soils. Two thin sections of a parent rock were analyzed to study its mineral composition. A particle size analysis of the soils indicates that the residual soil consists of mainly silt and clay (approximately 95%) and that soil textures are silty clay or silt clay loam. The soil colors of the residual soil are dark brown (7.5YR 3/4) through yellowish red (5YR 4/6). The pH of the residual soil ranges from 4.3 to 5.1. The major minerals of the parent rocks were quartz, biotite, chlorite, and plagioclase. The mineralogy of the sand fraction of the residual soil was quartz, biotite, muscovite and sanidine. The mineralogy of the silt fraction of the residual soil was quartz, biotite, muscovite, Na-feldspar, K-feldspar, and sanidine. The clay mineralogy of the soil was goethite, kaolinite, ilite, hydroxy-interlayed vermiculite(HIV), vermiculite, mica, K-feldspar and quartz. The mineral composition of the residual soil and the parent rock indicates that feldspar and mica in the parent rock weathered into illite, vermiculite and hydroxy-interlayed vermiculite(HIV), and finally changed into kaolinite and halloysite in the yellowish residual soils.