• The Journal of Engineering Geology
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• v.17 no.3
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• pp.393-404
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• 2007

The purpose of this study is to capture the essentials in survey and evaluation scheme which are able to assess the hazard of a rock slope systematically. Statistical analysis are performed on slope instability parameters related to failure of the rock slope. As the slope instability parameters, twelve survey items are considered such as tension crack, surface deformation, deformation of retaining structures, volume of existing failures, angles between strike of discontinuity and strike of cut slope face, angles between dip of discontinuity and dip of cut slope face, discontinuity condition, cut slope angle, rainfall or ground water level, excavation condition, drainage condition, reinforcement. A total of 233 road cut slopes located in Gyeongnam were considered. The stability of the road cut slopes were evaluated by estimating the slope instability index(SII) and corresponding stability rank. 126 rock slopes were selected to analyze statistical relation between SII and slope instability parameters. The multiple regression analysis was applied to derive statistical models which are able to predict the SII and corresponding slope stability rank. Also, its applicability was explored to predict the slope failures using the variables of slope instability parameters. The results obtained in this study clearly show that the methodology given in this paper have strong capabilities to evaluate the failures of the road cut slope effectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.3
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• pp.11-18
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• 1984

There are two different methods in the stability analysis of slopes depending upon the 1ocations and the types of assumed failure planes, which are the infinite slope analysis and the finite slope analysis. The infinite slope analysis is simple and easier in its application. However, since the method neglects the end effects and assumes the failure plane to be located at the shallow depth and parallel to the slope, the slopes to be analyzed by the method should be limited to a certain range. Thus, it is intended in this paper to define the infinite slopes whose stability may be analyzed by the infinite slope analysis. As a result, it is obtained that the method of infinite slope analysis may be applied to the slopes which have the ratio of the slope height to the depth of the failure plane of 9 or bigger.

• The Journal of Engineering Geology
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• v.10 no.2
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• pp.1-17
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• 2000

In this study, 270 cut-slopes are investigated and statistical analyses are performed. More than 84% of unstable slopes are rock slopes or rock-soil mixed slopes, and 72% of the slopes have 10 to 30 meter in height. And in order to clarify the cause of failure, 3 slopes which have been failed are back-analysed by using the computer programs such as DIPS, UDEC and PCSTABL5M. A heavy rainfall during rainy season is a main cause of slope failure, and a blasting vibration during construction could also give a significant influence on the slope instability.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.1
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• pp.67-74
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• 1998

This paper performed terrain analysis using DTM(digital terrain model) with TIN/ GRID structure on PC environment. Contour layer from 1:5,000 scale map was used to produce DTM. DTHs were produced with and without considering breakline for each data structure. Processing time, file size, mean elevation and standard variation were analyzed for each DTM. slope map, aspect map were analyzed for grid structure with consideration of TEX>$5\times{5m},\;l0\times{10m},\;15\times{15m},\;l0\times{30m},\;45\times{45m},\;60\times{60m}$ cell size respectively. The results suggest following; The incorporation of breakline does improve mapping accuracy for highly disturbed landscape, Mean elevation doesn't increase as the grid size increases, while processing time, storage room is significantly lessened. Thus, the optimal grid size must be determined in advance for efficient application. slope decreases, while aspect increases as grid size is increasing.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.447-453
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• 2003

연구지역은 경남 양산시 상북면 삼삼리 일원으로 양산단층과 인접하며 급한 경사의 자연사면으로 이루어져 있다. 수치지형자료를 이용하여 고도값을 갖는 자료층을 추출한 후 10m$\times$10m 크기의 격자별로 DEM으로 변환하고, 이로부터 단위 격자의 경사도, 경사방향도, 음영도를 작성하고 흐름분배 알고리즘을 이용하여 설정된 격자별로 상부사면의 기여면적과 습윤지수를 산정하였다. 높은 습윤지수를 보이는 지역은 북서-남동 방향의 선형구조로 나타나며, 국소지역의 전단단열 특성과 일치한다. 한편 연구지역에서 전기비저항 탐사를 실시하여 높은 습윤지수를 나타내는 지역과 저비저항 이상대의 분포를 비교한 결과 습윤지수가 높은 지역은 모두 낮은 전기비저항 이상대로 관찰된다. 즉 습윤지수는 암석의 화학적 풍화를 수반하는 파쇄대의 분포와 일치하며 이를 토대로 국소지역에서 파쇄대의 예측과 암석의 안정성을 예측하는 방법으로 이용될 수 있다.

• The Journal of Engineering Geology
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• v.32 no.2
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• pp.209-219
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• 2022

To experimentally investigate the variation of soil characteristics in slope during rainfall and the shape of slope failure, the model test was performed using soil box and artificial rainfall simulator. The model test of slope formed by the homogenous sand was performed, and the saturation pattern in the model slope due to rainfall infiltration was observed. The slope model with the inclination of 35° was set up on the slope of 30°, and the rainfall intensity of 50 mm/hr was applied in the test. The soil depth of 35 cm was selected by considering the size of soil box, and the TDR (time domain reflectometry) sensors were installed at various depths to investigate the change of soil characteristics with time. As the result of model test, the slope model during rainfall was saturated from the soil surface to the subsurface, and from the toe part to the crest part due to rainfall infiltration. That is, the toe part of slope was firstly saturated by rainfall infiltration, and then due to continuous rainfall the saturation range was enlarged from the toe part to the crest part in the slope model. The failure of slope model was started at the toe part of slope and then enlarged to the crest part, which is called as the retrogressive failure. At the end of slope failure, the collapsed area increased rapidly. Also, the mode of slope failure was rotational. Meanwhile, the slope failure was occurred when the matric suction in the slope was reached to the air entry value (AEV) estimated in soil-water characteristic curve (SWCC).

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.93-101
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• 2005

The formation of slopes is unavoidable under the special circumstance of Korea where $7%$ of the whole area are composed of mountains and civil engineering projects such as road and site developments are increasing with industrial development and horizontal expansions of urban area. Stability of slopes is one of quite important issues under special meteorological characteristics that over two-thirds of annual average rainfall is concentrated in summer season and the localized torrential downpour is getting more frequent recently. As a result of these circumstances, partial slope failures by debris flow of the high water content soils occur frequently in cut soil slopes. In this case of debris flow slope failure, slope declination method is selected fur the stable recovery because it is impossible to recover entirely by existing recovery methods. Seeding or special grass planting methods are followed separately without exception. The method by which entire recover with bigger stability ratio would be possible and grass planting work would be done simultaneously is developed. For debris flow failure slopes, this study secured the safety of slopes by preventing the inflow of rainwater and scour using geosynthetics-reinforced embankment, and created nature-friendly slopes by planting trees on the slopes.

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.342-345
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• 2005

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.289-291
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• 2007

• Journal of the Korean Geophysical Society
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• v.5 no.2
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• pp.111-129
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• 2002

Generally, investigation methods of cut slope are conucted only geological surface survey to gain engineering geological data of cut slopes. These methods have many problems such as limitations of investigation for a special area. So geophysical investigations such as geotomography, seismic and electrical resistivity methods have been used to search for failure surface in potential failure slopes or failed slopes. But investigation method using the borehole camera is recently a used method and it is thought that this method is more reliable method than other investigation methods because of being able to see by the eyes. Therefore, this paper was conducted investigations of borings and BIPS(Borehole Image Processing System) to search for potential sliding surfaces and was applied to obtain information of discontinuity on failed and potential failure slope in highway. As the results of BIPS, we could decide potential sliding surface in the slope, conducted to check slope stability and decided slope stability measures.