• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.1053-1059
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• 2009

In this study, slope hazards mitigation methods for a natural terrain are systematically classified to survey the mitigation methods and develop a data base system. Also, field survey sheets which can be recorded the features of mitigation methods installed in the natural slope are developed. The slope hazards mitigation methods in the natural slope are classified as hillside part method and valley part method. The slope part sheet and the valley part sheet are also drawn up for field survey. As the result of the filed survey of mitigation methods about 50 points in Muju and Jangsu area, grass painting and slope covering methods are dominant in case of slopes part. In case of valley part, slit dam, concrete check dam and slope foot barrier are applied simultaneously.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.233-242
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• 2009

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in crystalline rocks like gneiss, granite, and so on, a prediction model was developed by the use of a decision tree model. The classification standard of the selected prediction model is composed of the slope angle, the coefficient of permeability and the void ratio in the order. The computer program, SHAPP ver. 1.0 for prediction of slope hazards around an important national facilities using GIS technique and the developed model. To prove the developed prediction model and the computer program, the field data surveyed from Jumunjin, Gangneung city were compared with the prediction result in the same site. As the result of comparison, the real occurrence location of slope hazards was similar to the predicted section. Through the continuous study, the accuracy about prediction result of slope hazards will be upgraded and the computer program will be commonly used in practical.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1365-1371
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• 2008

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in gneiss area, a prediction technique was developed by the use of a decision tree model. The slope hazards data of Seoul and Kyonggi Province were 104 sections in gneiss area. The number of data applied in developing prediction model was 61 sections except a vacant value. The statistical analyses using the decision tree model were applied to the entrophy index. As the results of analyses, a slope angle, a degree of saturation and an elevation were selected as the classification standard. The prediction model of decision tree using entrophy index is most likely accurate. The classification standard of the selected prediction model is composed of the slope angle, the degree of saturation and the elevation from the first choice stage. The classification standard values of the slope angle, the degree of saturation and elevation are $17.9^{\circ}$, 52.1% and 320m, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.878-883
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• 2005

This paper describes the effect of acid rock drainage(ARD) produced from the cut slope on the slope structures. Acid rock drainage is originated from a rock quarry located in coal mine zone and mineralization belt of Chosen Supergroup and Ogcheon group, andesite with the pyrite, and acid sulfate soils of Tertiary in Korea. The cut slope, where acid rock drainage comes out, almost has been constructed by shotcrete and planting works. According to the field observation results, in most cases, the acid rock drainage has an adverse effect on slope structures. The shotcrete, anchors and rock bolts produced corrosive action, and bad germination and growth diseases of covering plants of the slope planting construction due to ARD.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.644-651
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• 2006

In general, a damage that occurs due to landslide or slope failure in urban areas is larger than that in rural areas. In order to reduce the damage, a program is necessary to categorize slopes based on properties and to manage them systematically. Based on the above necessity, a slope management program which is applicable to slope management in an urban area has been developed at Hwangryung mountain in Busan as a target area. The program has a function of systematic slope information constructed by slope ID number of each slope or sub-region of a mountain, making a slope data sheet, analysis and grouping of slope stability, and establishment of a data base. It can also be utilized practically by end users due to the convenient input, edition, printing, management and operation of slope data. For practical utilization of the developed program, a research related to construction of the slope management system for a regional area is demanded to be performed continuously. The supply and utilization of a web based slope management system would contribute to damage reduction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2C
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• pp.59-69
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• 2009

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in crystalline rocks like gneiss, granite, and so on, a prediction model was developed by the use of a decision tree model. The classification standard of the selected prediction model is composed of the slope angle, the coefficient of permeability and the void ratio in the order. The computer program, SHAPP ver. 1.0 for prediction of slope hazards around an important national facilities using GIS technique and the developed model. To prove the developed prediction model and the computer program, the field data surveyed from Jumunjin, Gangneung city were compared with the prediction result in the same site. As the result of comparison, the real occurrence location of slope hazards was similar to the predicted section. Through the continuous study, the accuracy about prediction result of slope hazards will be upgraded and the computer program will be commonly used in practical.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.45-54
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• 2008

Based on the data obtained from field investigation and soil testing to slope hazards occurrence section and non-occurrence section in gneiss area, a prediction technique was developed by the use of a decision tree model, which is one of the statistical analysis methods. The slope hazards data of Seoul and Kyonggi Province, which were induced by heavy rainfall in 1998, were 104 sections in gneiss area. The number of data applied in developing prediction model was 61 sections except a vacant value. Among these data, the number of data occurred slope hazards was 34 sections and the number of data non-occurred slope hazards was 27 sections. The statistical analyses using the decision tree model were applied to chi-square statistics, gini index and entrophy index. As the results of analyses, a slope angle, a degree of saturation and an elevation were selected as the classification standard. The prediction model of decision tree using entrophy index is most likely accurate. The classification standard of the selected prediction model is composed of the slope angle, the degree of saturation and the elevation from the first choice stage. The classification standard values of the slope angle, the degree of saturation and elevation are $17.9^{\circ}$, 52.1% and 320 m, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.302-311
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• 2008

There have been repetitive landslides and debris flows on natural terrain induced by intensive rainfalls which have never been experienced during the last a few decades in Korea. Frequencies and magnitudes of landslides and debris flows are steeply increased after 2000 resulting in huge damages of human beings and facilities. According to a statistical data from NEMA, the human deaths induced by landslides and slope hazards occupies 22.3% of the total human deaths by all the natural hazards in Korea during the last 30 years. Among the human deaths by landslides and slope hazards, 85% of the damages were caused by landslides and debris flows on natural hazards. Therefore, this paper summarizes important events of landslides and debris flows, their characteristics, and suggests some methods of damage mitigation.

• The Journal of Engineering Geology
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• v.17 no.2 s.52
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• pp.289-297
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• 2007

Slope failure that is occurred by rainfall generates a lot of property damages and loss of lives. Slope stability management and reinforcement countermeasure can be attained through continuous monitoring about various slope types that adjoin in human's life for reducing slope failure from natural and artificial cut slope hazards. The study area is rock slope that is consisted of gneiss, and large scale joint set is ranging by fault activity. This rock mass is exposed during long period and has lithological weathering property of weathered rock or soft rock. In-situ investigation carried out after divide by natural slope and cut slope. As a result, the natural slope appeared to high possibility of planar failure and wedge failure in few joint points that main joint set is formed. On the other hand, slope failure conformation in cut slope was superior only wedge failure occurrence possibility in eight joint points. In result of numerical analysis using SLIDE 2D, the minimum safety factor was analyzed slope stability for cut slope relatively low than natural slope in this study.

• Journal of the Korean Geosynthetics Society
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• v.7 no.2
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• pp.31-39
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• 2008

The information of cut slope in Baekyang Mt. area, Busan is investigated in order to construct the Slope Management System in Urban Area. The slope inspection sheet is made to record the characteristics for cut slopes, and that is capable to be inputted slope information systematically. The cut slopes in Baekyang Mt. area are consisting of 103 slopes. Most of the cut slopes are constructed in cutting slope and retaining wall (CR). The school is mostly distributed adjacent to cut slopes. The average traverse of cut slopes is approximately 122m, and the average height is approximately 18m. The slopes combined with soil and rock are mostly distributed. The retaining wall was installed in the toe part of cut slope in order to increase the slope stability, and the additional reinforcement methods including the anchor, drainage, preventing rock fall, shotcrete and vegetation were installed in the walls and slopes.