• The Journal of Engineering Geology
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• 제15권2호
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• pp.133-144
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• 2005

Stability investigations were conducted for the heap of coal associated wastes occurred from D mine located in Gang-Won Province from the geotechnical and environmental engineering aspect, and a countermeasure was also examined to increase the stability in this area. Quality of water flowed from the heap of coal associated wastes was identified as Am. Slope stability investigations were conducted with both circular failure analyses using SLOPILE program and planar failure analyses in cases of dry, rainy, and ordinary slopes. The results of circular failure analyses indicated that the factor of safety is 0.78 for rainy case. for planar failure analyses, the factor of safety decreases with increase the depth and reaches below 1 about 4m depth for rainy case. A retaining wall system with backfill using the recycled-concrete aggregates as a practical scheme was suggested to satisfy both demands: reducing Am generation, and enhancing slope stability in the deposits of coal associated wastes.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 한국암반공학회 1996년도 정기총회 및 학술발표회
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• pp.55-72
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• 1996

암반사면의 안정성은 암반내에 발달된 불연속면의 기하학적 속성과 강도정수에 크게 영향을 받으며, 사면방향에 대한 불연속면들의 상대적인 방향성들은 구조적으로 발생 가능한 붕괴양상을 결정하게 된다. 불연속면을 따라 미끄러짐이 발생하는 암반사면의 불안정성 분석에는 결정론적인 해석(deterministic analysis)과 확률론적인 해석(probabilistic analysis)들을 포함하여 수많은 방법들이 이용되고 있다. (중략)

• The Journal of Engineering Geology
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• 제23권3호
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• pp.283-292
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• 2013

A calcareous rock slope failed during excavation of the slope for construction of a tunnel entrance. The slope is located at the construction site for widening highway in Yeongwol, Korea. Field surveys, laboratory tests, and numerical analyses were performed to determine the reason for the slope failure. The numerical analysis revealed that the safety factor of the slope before construction of the entrance was less than 1, and that this decreased after construction. After construction of the entrance, the sliding zone of the slope increased and slope stability decreased because the shear strain and plastic zone in the slope over the tunnel entrance showed an increase relative to the lower part of the slope. To enhance the stability of the slope for construction of the tunnel entrance, countermeasures such as rock bolts, rock anchors, and FRP (Fiber glass Reinforced Plastic) grouting were adopted in light of the field conditions. Serial field monitoring performed to confirm the reinforcing effects of the adopted countermeasures revealed a small amount of horizontal deformation of the slope soils, most of the elastic deformation that can regain its former value. In addition, the axial forces of the rock bolt and anchor were more strongly affected by slope excavation during construction of the tunnel entrance than by tunnel excavation or the rainy season, and the axial forces tended to converge after excavation of the tunnel. Therefore, we can confirm that the slope is currently safe.

• The Journal of Engineering Geology
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• 제20권4호
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• pp.437-447
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• 2010

A probabilistic analysis of slope stability is an appropriate solution in dealing with uncertainty in problems related to engineering geology. In this study, a Monte Carlo simulation was performed to evaluate the performance function that is Barton's equation. A large number of randomly generated values were obtained for random variables, and the performance function was calculated repeatedly using randomly generated values. A previous study provided information of slope geometry and the random characteristics of random variables such as JRC and JCS. The present approach was adopted to analyze two failed slopes. The probabilities of failure were evaluated for each slope, and sensitivity analysis was performed to assess the influence of each random variable on the probability of failure. The analysis results were then compared with the results of a deterministic analysis, indicating that the probabilistic analysis yielded reliable results.

• Proceedings of the KSEEG Conference
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• 대한자원환경지질학회 2007년도 춘계 지질과학기술 공동학술대회
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• pp.646-648
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• 2007

• Journal of the Korean Geophysical Society
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• 제5권2호
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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.

• The Journal of Engineering Geology
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• 제25권2호
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• pp.189-199
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• 2015

Our country's leading granite weathered soil of the ground slope failures that occur in cutting slope most cases, it does not require in-depth to the shear strength most of the surface layer is affected by weathering (1~2 m) at a shallow depth close to the ground, it is important to identify the reliability. Based on the result obtained in actual field investigation, the field slope type was classified by each type of wedge slope, Infinite slope, finite slope -I and finite slope -II, and the slope stability was examined respectively. In addition, using the numerical analysis results, the relationship between the slope inclination angle and safety factor was analyzed and it tried to offer basic data to which the stability in the field slope was able to be estimated by analyzing the safety factor change of the slope according to the slope type. In this study, classified into four types of natural slope, safety factor estimation method by slope types is proposed through the numerical analysis. However, some limit exists in generalizing in this research because it does not test various case studies. Therefore, the case study of a wide range of various sypes to assess the safety of various types slope can be made, accommodate a wide range of field conditions reasonable risk evaluation criteria may be derived.

• Journal of the Korean Geotechnical Society
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• 제20권1호
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• pp.121-129
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• 2004

In this study, a slope stability chart for assessing stability of homogeneous simple soil slopes is proposed. Most existing slope stability charts are based on limit equilibrium method, which is not rigorous in mechanical standpoint. Meanwhile, limit analysis based on the principle of virtual work and the bound theorems of plasticity is suitable for evaluating the stability of geotechnical structures such as slope due to its simplicity in computation and mechanical rigor. Numerical limit analysis taking advantage of finite elements and linear programming can consider various slope conditions and, in addition, find the optimum stability solution with effeciency. In this study, a numerical limit analysis program in terms of effective stress is developed and a mechanically rigorous slope stability chart is proposed by performing stability analyses for various slope conditions. Pore pressure ratio, commonly used in stability charts, is applied to consider the effects of pore pressure for effective stress analysis. As a result of comparison between proposed stability chart and Spencer's stability chart, it was found that Spencer's chart solutions are biased to lower bound which means conservative in design.

• Journal of the Korean Geotechnical Society
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• 제16권5호
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• pp.141-148
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• 2000

사면 안정 해석은 주로 파괴 활동면의 전단 강도와 발휘되는 전단 강도의 최대비로서 표현되는 파괴활동의 추정을 위해 기존의 고전적인 방법을 사용하거나 이와 유사한 방법등이 사용되어 왔다. 이러한 방법들은 토질에 있어서의 상호 작용력과 그에 따른 전당력 및 사면 활동면의 반복되는 추정등의 가정으로 불확실성을 내포하고 있다. 본 연구에서는 토질전체를 연속체로 규정하고 비선형 유한요소법을 이용한 토질의 실제 응력과 강도를 정확하게 계산하였다. 사면 안정은 점차적 인증력의 증가로서 사면의 붕괴 활동면이 나타나FEo 까지로 해석되었다. 제시된 방법의 세부적인 사항은 예제를 통하여 설명되어 있다.

• The Journal of Engineering Geology
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• 제14권4호
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• pp.451-460
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• 2004

The strength of sliding plane is usually assigned on the whole sliding plane with same value in 2D limit equilibrium slope stability method. However, the potential sliding plane is divided into two or three parts which have different sliding resistances. According to the calculation results of 3D slope stability analyses using 4 types of slope cutting models, marginal sliding resistance could affect the safety of slope significantly. In this calculation two kinds of the sliding plane strengths were applied differently to the parts of bottom and margin of the model slope. The effect of marginal resistance was calculated quantitatively. In case of lower sliding resistance of the bottom, the safety factor becomes low in a margin cutting model. However, in case of higher sliding resistance of the bottom, the safety factor decreased slightly in a lower part cutting model and increased in a upper margin cutting model.