• The Journal of Engineering Geology
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• v.13 no.2
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• pp.157-170
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• 2003

This study is performed to investigate the cause of slope failure and to suggest suitable stabilization methods for the failed rock slopes. The slope which is located along the national highway between Maesan and Kakok in Dangjin-gun failed during the construction of roads. Site investigation, drilling program, field measurements, rainfall records, and stability analyses are used to investigate the cause of the slope failure. The problem determining the cut-slope angle based on the existing design manual for the construction of roads is reviewed based on the case history given in this paper. If weakness layer and geological structures such as folds and faults are developed in a slope, slope failure is possible even though the direction of slope and the direction of discontinuities depart more than $30^{\circ}$.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.137-146
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• 2014

The geology of the study area which is located in Samkoe-dong, Dong-gu, Daejeon city comprises black slate, limestone, and pebble-bearing phyllitic rock as meta-sedimentary rocks; and biotite granite and quartz porphyry intrusions. Face mapping revealed sliding in three or four sites of contained coaly slate, where the dip of the foliation and other discontinuities is parallel to the surface slope. The cause of the slope sliding is this parallelism as well as the swelling of the coaly slate when wet. In contrast, the slop on the opposite side of the road is relatively stable because the dip of the foliation and other discontinuities are oblique or normal to the surface slope. To ensure slope stability, a cut-and-cover tunnel was designed and constructed for the new road.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.189-199
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• 2006

This paper presents a field study of the stability of slope collapsed during road construction and proposes a reasonable countermeasure if the current slope is unstable. As a result of slope investigation, it was found that the slope includes five tension cracks and the sliding surface is started from the tension crack and propagated the surface soil layer through weathered rock layer. The slope stability analyses are conducted in case of dry and rainfall seasons. The results indicate that the slope is unstable status. A reinforcement method of slope failure should be selected according to the scale of failure. That is, the scale of slope failure, which is classified small, middle and large size determines the reinforcement method of slope. Since the slope interested in this study is large size failure slope, the reinforcement method to control slope failure is selected stabilizing piles, and seed spray and drainage of surface waterare also selected to remain the factor of safety. The SLOPILE (Ver. 3.0) program is applied in order to do stability analysis of slope reinforced by piles. As the result of analysis, the slope reinforced by a row of piles shows the stable state. It is clearly confirmed that the stabilizing of piles can improve the stability of slope.

• The Journal of Engineering Geology
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• v.15 no.2 s.42
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• pp.155-168
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• 2005

The behavior of earth retention wall installed in a cut slope is different from the behavior of retention wall applied in an urban excavation. In order to establish the design method of anchored retention wall in the cut slope, the behavior of anchored retention wall needs to be investigated and checked in detail. In this study, the behavior of anchored retention wall was investigated by the instrumentation installed in the cut slope, where was stabilized by a row of piles in an apartment construction site. The horizontal displacement of anchored retention wall was larger than the displacement of slope soil behind the wall at the early stage of excavation. As the excavation depth became deeper, the horizontal displacement of slope soil was larger than the displacement of anchored retention wall. It means that the horizontal displacement of anchored retention wall due to excavation is restrained by soldier pile stiffness and jacking force of anchor at the early stage of excavation. lacking force of anchor was mainly influenced on the horizontal displacement of anchored retention wall. The displacements of anchored retention wall and slope soil were affected mainly by rainfall infiltrated from the ground surface. Meanwhile, the horizontal displacement of anchored retention wall with a sloped backside was about $2\~6$ times larger than the displacement of anchored retention wall with a horizontal backside of excavation.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1395-1399
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• 2004

절개지사면에 구조물이 설치될 경우 배수압소산과 식생복원을 위해서는 기본적으로 다공성이 뛰어나고 식생의 서식이 가능한 구조물로 설계되어야 하며, 동시에 사면의 안정을 제공해주는 기능을 할 수 있어야 한다. 구조물이 설치될 지역에 Mattress/Filter를 사용할 경우 배수압의 소산과 식생의 활착이 가능한 구조물로 사면의 안정과 식생복원효과를 검토하였다. 본 연구에서는 절개지사면에 토목구조물이 설치될 경우 식생의 복원과 구조물의 안정성을 높이기 위한 기법으로 Mattress/Filter에 Slag를 채워서 다공성을 부여함으로써 사면의 배수압소산과 식생촉진 뿐만 아니라 사면의 안정성을 제공해줄 수 있는 구조이다. 특히, Mattress/Filter는 다공성이 뛰어나 자연배수가 가능한 구조물로서 그 구변 생태계에 필수적인 물의 상호교류 즉, 투수와 배수가 가능하고 배수압의 소산이 가능하여 식생복원과 사면안정에 우수한 것으로 나타났다. Mattress옹벽은 배면의 지하수 배제를 촉진시켜 사면의 안정화에 기여하게 되려, 식생의 복원에 뛰어난 효과가 있는 것으로 나타났다. 또한 Mattress에서 Fitter의 채움 재료로 산업계기물(Slag) 및 건설폐기물(폐콘크리트, 사석) 등을 재활용할 수 있으므로 Mattress는 채움재료의 비용이 저렴하고 유지관리가 용이하며, 생태계의 보존에도 Mattress/Filter의 사용은 매우 효과적임을 알 수 있었다.

• The Journal of Engineering Geology
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• v.19 no.1
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• pp.89-98
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• 2009

Existence of core stone at the inside of the Rock mass is reacting as unstable element. In particular, in case of the cut slope, even when it is not exposed, slope's discontinuity increases or strength level decreases depending on the difference in the weathering grade when it comes to the core stone, and reacts as an important element of the slope movement such as slope's rock fall or collapse. As for the slope that is subject to study, incision was completed after 20 years or so, and parts of the slope reinforcement was completed, but frequent rock fall occurs despite small amount of rainfall, and permanent stability measures are urgent. Refractional seismic survey and geological survey results were compared and analyzed, and reliability was improved by complementing the two survey methods, and stereo-graphic projection using DIPS program was conducted to analyze the characteristics of oore stone in the weathered soil slope.

• Proceedings of the Korean Geotechical Society Conference
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• 1995.06a
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• pp.9-24
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• 1995

• Proceedings of the Korean Professional Engineer Association Conference
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• 1994.10a
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• pp.125-130
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• 1994

• Magazine of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.73-80
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• 2005

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.57-64
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• 2004

In order to establish the design method of anchored retention walls in cut slope, the behavior of anchored retention walls and backside ground needs to be investigated and checked in detail. In this study, the behavior of anchored retention walls was investigated by instrumentation installed in cut slope for an apartment construction site stabilized by a row of piles and anchored retention walls. When the anchor was installed at each excavating stages, the horizontal deflection of retention wall decreased, while the horizontal deformation of backside ground increased. The deflection of anchored retention wall decreased as the anchor was prestressed. The prestressed anchor farce has a great effect on the deflection of retention walls, while it has little effect on the deformation of its backside ground. The maximum horizontal deflection of anchored retention walls was developed between $1\%\;and\;4\%$ of excavation depth, which are $2\~8$ times larger than max. horizontal deflection of anchored retention walls including rock layers with backside horizontal ground. Meanwhile, SLOPILE (ver. 3.0) program analyzes the slope stability effects for anchored retention walls. As a result of analysis on slope stability analysis, the lateral earth pressure applied at anchored retention piles could be used as the mean values of empirical lateral pressures using anchored retention wall with horizontal ground at its backside.