• Journal of the Korean GEO-environmental Society
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• v.20 no.1
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• pp.43-49
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• 2019

In this paper, we introduced phase optimization techniques in the Soil-Nail design to optimize the reinforcement required for each grade level. The optimal design results at the maximum slope height were further amplified to allow for phase optimization of the horizontal spacing of the Nail in accordance with the change in the height of the slope. The limit equilibrium analysis was performed by step-by-step sloping height, and the safety factor exceeded when the horizontal spacing of four days was fixed. The process of optimization was effectively carried out by densifying the required reinforcement depending on the slope elevation. Also limited to reflect the axial force of the nail into the reinforcement details.Using the method, the members' strength was reflected. When phase optimization technique is applied for each slope height by calculating the stiffening precision, it is judged that it will be more economical to optimize horizontal intervals by effectively reducing the repeated reinterpretation process that satisfies the reference safety ratio for each slope height.

• Journal of the Korean Geosynthetics Society
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• v.20 no.4
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• pp.151-163
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• 2021

This paper is dealt with railway slope stability for slope reinforcement using a geosynthetic concrete composite mat(GCCM). Recently, according to a change in weather caused by global warming, train operation has been restricted by the loss of backfill slope at the roadbed, which is consists of gravel, due to typhoons and heavy rainfall. In addition, the amount of damage is getting more significant than the cost of restoration, and the safety of workers is worried. In order to improve this limitation, a slope stability analysis was applied with a rapid hardening composite mat so that it can quickly secure a construction surface with increased workability and work stability and reduce maintenance costs by preventing re-loss in case of heavy rain and fundamentally blocking vegetation. As a result of the analysis, it was confirmed that the increase in safety factor was confirmed when the rapid harding composite mat was applied.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2B
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• pp.249-259
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• 2008

The present paper studies the effect of the slope gradient of a fully permeable submerged breakwater using a newly developed numerical model that is able to consider the flow through a porous midium with inertial, laminar and turbulent resistance terms, i.e. simulate directly WAve-Structure (submerged breakwater)-Sand seabed interaction and can determine the eddy viscosity with LES turbulence model in 2-Dimensional wave field (LES-WASS-2D). The developed model was validated through the comparison with an existing experimental data, and further used for various numerical experiments in oder to investigate the complicated hydrodynamics on the varying slope gradient of permeable submerged breakwater. We found an acceptable phenomenon, as we expect intuitively, that reflection and transmission coefficients decrease simultaneously as slope gradient decrease. In addition, the breaking point, the circulation flow and mean vorticity around a submerged breakwater are throughly discussed.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.408-421
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• 2014

This study was carried out to investigate flora and vegetation in cutting slope along a construction age sequence (2007, 2009, 2010, 2011, 2012) of forest roads in Yongchiri, Younghyunmyon, Sacheonshi, Geyongsangnamdo. Mean slopes of the cutting and banking slopes of forest roads constructed were ranged from $42^{\circ}$ to $54^{\circ}$. Soil texture in the cutting and banking sides of forest roads constructed in 2012 was loam, while sandy loam in the cutting and banking slopes of forest roads constructed between 2007 and 2011. Vegetation cover percentage was higher in the banking slopes (66%) than the cutting slopes (49%) of forest roads. Total flora were higher in the banking slopes (50 species) than the cutting slopes (46 species) of forest roads. Species diversity was generally higher in the banking slopes than in the cutting slopes in all forest roads. In addition, the species diversity index was the highest in the cutting slopes (1.4015) of forest roads constructed in 2011, while the highest in the banking slopes (1.5603) of forest roads constructed in 2012. The results indicate that evenness index in the cutting and banking slopes of recent construction roads was high compared with old construction roads because of the distribution of simple plant species.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.1
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• pp.115-122
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• 2014

The purpose of this study is to analyze the relationship between height of cutting and filling as well as the height of slope of roadsides. It also suggests the rational height of slope to minimize topographical damage in road construction. Hence, in this study, 44 cases of expert's opinions related to height of slope in Environmental Impact Assessment(EIA) for road construction projects are reviewed, and 23 cases of data related to height of cutting and filling in EIA for road construction projects are used for analyzing relationship between height of slopes and height of cutting or filling of roadside. The results are as follows; Most of heights of cutting, filling and slope in EIA for road construction are over the required standards 20 or 30m(in case of cutting) and 10 or 15m(in case of filling). It also shows that there is high-level correlation between height of cutting and filling and height of slope of roadside. According to regression analysis, it is suggested that the general standard of each heights of cutting and filling are 25.33~33.23m(in case of cutting) and 14.56~18.08m(in case of filling), but it should be considered in EIA review for road construction projects that these heights suggested in this study are over the required standards.

• The Journal of Engineering Geology
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• v.21 no.4
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• pp.313-322
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• 2011

On September 2007, numerous slopes at Jeonranam-Do collapsed as a result of rainfall related to Typhoon Nari. Failure occurred at a road cut-slope on the ${\bigcirc}{\bigcirc}$ detour road, damaging transport infrastructure. This study aims to determine the cause of failure based on field investigations, the geotechnical properties of soil, clay mineral composition, and quantitative analysis. The studied cut slope consists of weathered soil that originated from volcanic rocks, and minor faults and a mafic dyke. Surface water tends to seep into the soil because the roadway is not sealed and because of poorly installed drainage. Sieve and XRD analyses indicate that soils in the failure zone are ML and CH, which are prone to swelling due to the presence of clay minerals such as smectite and vermiculite. The slope failed due to the improper construction of drainage facilities, the presence of geological weak zones, and high soil contents of swelling clay.

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.17-33
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• 2000

The construction of a public cemetery in Kangnung city includes terraced graveyard with cutting or banking in mountain which has severe altitude differences with a slope of $30^{\circ}$. Therefore, there are scattered cutting and banking sections with vertical height more than 15m. Especially, if the slope failure or the loss of a graveyard happens after graveyard establishment due to surface flow and inflow around. it is difficult to repair, causing serious public censure. Accordingly, revegetation works were examined that need protection of slope. The specific content of the study was the selection of slopes requiring special care through blueprint and field investigation. the measurement of the physical property of slope and the situation of vegetative growth, the investigation of vegetation in slopes and the selection of vegetation. and the analysis of soil condition of slopes and the physical condition of slope sediment. On the basis of investigations some alternatives were proposed.

• Journal of the Korean GEO-environmental Society
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• v.21 no.6
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• pp.13-17
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• 2020

In the era of the fourth industrial revolution, drones are being used in various civil engineering fields. Currently, the construction and maintenance of slopes are generally managed by manpower. This method has a risk of safety accidents, and it is difficult to accurately evaluate the slope because it is difficult to secure the vision. In this paper, the effects of RTK and GCP on the 3D model of the slope were studied by using digital images taken by the drone. GNSS coordinates were measured for nine points to compare the quality of the slope 3D model, three points of which were used as the check points and the remaining points were used as GCPs. When making the 3D model of the slope using high-accuracy geotagging images using RTK, it was found that the error at the check point decreases as the number of GCP increases. Even if GNSS was used, it was found that the error at the check points of the 3D slope model was not significant when the GCPs were applied. However, it was found that even if high-accuracy geotagging images are used using the RTK module, a significant error occur when the 3D slope model is created without applying GCPs. Therefore, it can be stated that GCP must be applied to create the 3D slope model in which information about the height as well as plane information is important.

• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.265-278
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• 1991

The purpose of this study is to suggest objective basic data for the design and management of the national park roadside slopes through the quantitative analysis of the visual quality included in the physical environment of the Chi-ri national park, for this, visual volumes of physical elements have been evaluated by using the mesh analysis, spatial images structure of physical elements have been analyzed by factor analysis algorithm, and degree of visual quality have been measured mainly by questionnaires. Result of this thesis can be summarized as fallows. Visual volumes of the naked, rock, ground cover of seed spray, and artificial planting are found to be the main factor determining the visual quality. Factors covering the spatial image of the national park roadside slopes landscape have been found to be the overall synthetic evaluation, spatial, appeal, physical, openness and dignity factors such as the overall the spatial, physical and openness yield high factor scores. As for the factors determining the degree of visual quality of the roadside slopes, variables such as the summit, the constructions management, harmony of landscape, visual stability of roadside slopes, suitable artificial planting and suitable constructions.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.476-488
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• 1997

The purpose of this study was to figure out the suitable field standards for revegetation measures on cut-slopes in consideration of the environmental factors. The field survey was conducted from 1995 to 1996 on highway cut-slopes. The results obtained could be summarized as follows; The major revegetation measures surveyed were 5 major measures as a whole in descending order of seed-spraying measures, block-sod pitching measures, latticed block pitching measures, hydro-seeding measures with seed-fertilizer-soil materials, and several netting measures on highway cut-slopes. According to the analysis of the environmental factors, the plant coverage was affected several major environmental factors which were soil factors(soil hardness, soil texture, soil and rock condition), and site factors(slope gradient, slope length). From a viewpoint of optimum selection, the major 3 factors(soil factors, slope gradient factors, slope length factors) should be considered for selection of revegetation measures on highway cut-slopes.