• Economic and Environmental Geology
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• v.33 no.1
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• pp.51-59
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• 2000

As a part of natural hazard assessment, regional slope stability analysis was conducted using Geoscientific Information System (GIS) in the northern area of Chungju Lake. Selected factors which affect the slope stability in the study area were lithology, soil, density of lineament, groundwater level, dip of slope, aspect of slope, and geological engineering properties. Geological structural domains were determined by collected data of joint orientation from about 200 sites in order to produce a slope instability map. Potential type of failure and its direction could be expected through the domains. And a slope instability map was produced, comparing the representative orientations of the domains with the orientations of the slopes which were made through TIN module in ARC/INFO. Under the consideration of environmental geological characteristics of the study area, rating and weighting of each factor of slope stability analysis were decided and spatial analysis of regional slope stability was couducted through overlaying technique of GIS. The result of areal distribution of slope stability showed that the most unstable area was the area between Mt. Pudae and Mt. Jubong, and the northern area of the railway station, Samtan.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.580-585
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• 2004

The purpose of this study is the stability evaluation of soil slope according to inclination of upper natural slope. Upper natural slope breeds loss of slope by inflow in slope of surface water by rainfal1 and f1uctuation of amount of materials in slope through method of cutting slope according to degree of inclination. Basis of standard inclination does not consider of inclination of upper natural slope and is presented uniformly. Therefore, in this study, analyzed stability of inclination of upper natural slope through limit equilibrium analysis. Result is same as following. First, safety factor through limit equilibrium analysis is almost direct decrease when gradient of soil slope is 1:1.2, 1:1.5. However, when gradient of soil slope is 1:1.0, 1:0.7, if sinclination of upper natural slope are $20^{\circ}$, it shows tendency that decrease of safety factor becomes low rapidly. Second, when when gradient of soil slope is fixed, inclination of upper natural slope increase tendency(maximum 3.0 times) that decrease of safety factor.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.1
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• pp.67-77
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• 2018

The objective of this study is to extract the shape of the slope from the images acquired using UAV and evaluate its suitability and reliability when applied to slope stability analysis. UAV is relatively inexpensive and simple, and it is possible to make terrain survey by generating point clouds. However, the image acquired from UAV can not be directly photographed by the forest canopy due to the influence of trees, resulting in severe distortion of the terrain. In this study, therefore, the effects of forest canopy were verified and the slope stability analysis was performed. Images acquired in winter and summer were used, because summer images are heavily influenced by the forest canopy and winter images are not. As a result of the study, the winter image is suitable for the extraction of slope shape, but severe terrain distortion occurs in the summer image. Therefore, slope stability analysis using slope shape extracted from summer image is impossible, so it should be modified for slope stability analysis. The modified slope did not completely eliminate the distortion of the terrain, but it could express the approximate shape of the slope. As a result of the slope stability analysis, the location and shape of the failure surface are the same, and the error of the safety factor is less than 0.2, which is close to the actual slope.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.1 s.108
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• pp.33-48
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• 2005

The purpose of this study was to discover the landscape visual image of the slope scene and their harmony with surrounding sceneries. This research utilized the basic study tool of psycho-physics and processed the case study of ten types of slope construction scene along the highway. The analysis was performed by the data obtained from the questionnaires and the photos for the slope construction scene. The questionnaires for analysis the image of the slope construction scene and their harmony with surrounding sceneries were designed using semantic differential scale and 5 point Likert-scale. The major findings were as follows. 1. At the part of the visual preferences analysis, the slope revegetation methods showed high level of preferences generally than on the slope structure methods. While the slope revegetation methods were estimated friendly, continuity, harmonious, soft, light and wide, the slope revegetation methods were estimated unstable, female, static, simple, omnipresent, appeared as policeman of weak inclination. Also the slope structure methods were estimated stable, manly, complicated, steep and healthy but rough, unharmonious, unfamiliar and heavy. 2. Psychological factors, related to the satisfaction for the slope revegetation methods were composed of three factors, aesthetic, individuality and physical character. And the slope structure methods were composed of five factors, aesthetic, individuality, stability, physical character, and complexity. 3. At the part of harmony with surrounding landscapes, the slope revegetation methods were evaluated highly but the slope structure methods received the lowest evaluation. Also the harmony analysis with surrounding view on the slope revegetation methods showed degree of high more than average in all texture, form, color and scale but the slope structure methods showed degree of fewer than average degree in form, scale, color and texture.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.736-744
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• 2009

The abrupt failure of slope caused by a concentrated rainfall would be a disaster in this country. Specially, the soil slope may be collapsed by the rainfall seepage, however, there is not much information for the mechanism of slope failure during rainfall. As analyzing the stability of slope by rainfall, the conventional method is to put the ground-water level on the surface of slope. However, it may provide the over-reinforcement for the slope stability. Futhermore, although over-reinforcement for the slope was fulfilled, the possibility of potential slope failure still exists. In this study, the slope stability by the conventional design method and the causes of unstable slope during rainfall were investigated. To analyze the slope stability by rainfall, the computer program SEEP/W for the analysis of seepage was used. As changing the intensity and duration of rainfall in SEEP/W, the analysis were performed. After completion of analysis, the porewater pressure data from SEEP/W was applied to SLOPE/W. As a results of this analysis, it is not reasonable that the groundwater level is going up to the surface of slope during rainfall. Therefore, the conventional reinforcement for the slope stability is not obvious to satisfy the criterion safety factor during rainfall. The reasonable counterplan is to install drainage hole on the surface of slope in order to prevent erosion and debris flow.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.263-266
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• 2007

In this paper, analysis results on the failure of slope behind a Plant Complex of Gimhae due to typhoon Rusa in 2002 are introduced. The left side of the slope was reinforced by soil nails and the right side of the slope was going to construct slope reinforcement works. In the slope failure, the damage area is about $34,000m^2$, the lower width of slope failure is about 230m, the upper width of slope failure is about 50m, and the height of slope failure is about 120m. The elevation of a bedrock in the right side of the slope was lower than the left side of the slope. Due to the depth of weathered soils and weathered rocks in right side of the slope was thick, it will be expected that the effects of pore-water pressure during the rainfalls are large. For the analysis of the failure mechanism, 3-dimensional numerical analysis was carried out by FLAC-3D.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.561-564
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• 2008

Rock slope had been slope failure due to geological and physical things over time. In this paper, it discusses rock slope stability analysis which was concerned about additional slope failure located near the Andong-si. Initially, achieved basic geological investigation and field test about rock slope, examine the stability of rock slope by doing limit equilibrium method and stereographic projection about 5 slopes.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.457-464
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• 2000

Stereographic method is a general and basic method to analyse sliding failure potential of rock slope. Region of failure analysis using stereographic method extend to curved slope from straight slope in this paper, Curved slope is defined as the multi-face slope with free surface more than two face and has different characteristics from straight single face slope. Individual daylight envelopes of free surfaces are combined into total daylight envelope of multi-face slope. So, sliding envelope of multi-face slope is the daylight envelope except friction cone. Specially, If only single joint set is developed in the slope, single plane sliding(or plane failure) is impossible in the single-face straight slope, but possible in the multi-face slope. In the multi-face slope with only one joint set, single plane sliding occurs when orientation of sliding plane is between two side slope orientation in the sliding envelope.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.183-190
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• 2001

There are complicated and big shear zone which is about several tens meter in the middle of the cutting slope in this study area. And slope stability analysis is very hard because many fault zones are gathered in the shear zone. This study furnish imformations of scrutinized geological survey, numerical stability analysis, reinforcement work analysis and computation of ground mass properties. Then this offer rational slope stability analysis, rock mass decision and counterplan.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.957-965
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• 2008

Recently, slope stability analysis in current design criteria is criticized for its unrealistic assumption of groundwater table and slope stability analysis incorporating seepage analysis considering rainfall is gaining a recognition as an alternative. However, a reasonable method for determining the rainfall used in the seepage analysis has not yet been established. Rainfall input for seepage analysis is a time series of rainfall and is similar to the hyetograph which is usually obtained from hydrology. In this paper a method to obtain the hyetograph from the intensity-duration-frequency is proposed. The resulting hyetograph can be used in the in the slope design stage. Also some considerations for practical application of slope stability analysis considering the rainfall is included.