• Proceedings of the KSEG Conference
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• 2002.04a
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• pp.75-83
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• 2002

국내 절개면은 대개 절개면의 구성물질에 패한 지질공학적인 특성과 구성물질내의 지질구조 등에 대한 충분한 고려가 수행되지 않은 상태에서 구성물질의 강도에만 의존하여 설계·시공되었다. 따라서 매년 강우기와 해빙기에 반복적인 붕괴사고가 발생하고 있으며 이로 인한 인명피해와 재산손실이 매년 발생하고 있다. 따라서 절개면의 붕괴를 방지할 수 있는 근본적인 대책안의 제시와 함께 절개면에서 발생하는 붕괴를 예방하고 붕괴특성 및 붕괴 원인 규명을 위한 기초 연구로서 국내의 절개면에 대한 지질공학적인 특성 연구가 절실한 실정이다. 본 연구는 2001년 한국건설기술연구원에서 수행한 362개소의 절개면을 대상으로 절개면의 구성물질 및 지질구조에 대한 지질공학적 특성을 분석하였다. 본 연구는 국내에 분포하는 절개면의 붕괴 특성과 붕괴 인자에 대한 기초 연구로 차후 국내 절개면에 대한 설계기준을 재정립하고 절개면에 대한 효율적인 관리를 수행하기 위한 기초 자료로 사용될 수 있을 것으로 판단된다.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.713-727
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• 2009

절토비탈면의 붕괴는 주로 지질구조 적으로 취약한 구간에서 강우, 지진, 발파진동, 굴착 등의 외적인 요인이 작용하였을 때 비탈면의 붕괴가 수반되는 경우가 많으며 내적인 요인으로 작용하는 지질구조는 구조선의 종류에 따라 붕괴규모나 붕괴양상에서 상당한 차이를 보이는 특성을 보인다. 특히, 비탈면 붕괴는 단층이나 점토가 충전된 구조선에서 문제가 많이 발생되고 방향성이 뚜렷한 엽리 및 절리에서 붕괴가 빈번한 실정이다. 단층은 일반적으로 모든 암종에서 나타나는 지질구조이나 특히, 변성암중 편마암에서 붕괴빈도가 빈번하게 발생되고 점토층이 수반되는 경우에 심하다. 본 논문은 공사당시 비교적 규모가 크게 붕괴가 발생된 붕적층 절토 비탈면과 단층파쇄대 및 암질불량의 비탈면의 붕괴사례의 안정검토 사례를 소개하고자 한다.

• 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 $30^{\circ}$.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.213-227
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• 2002

절토사면의 붕괴원인은 토질 및 지질조건, 지형, 강우, 지하수 및 지표수, 사면형상, 굴착 및 발파와 같은 인위적인 조건, 사면보호공 등과 같이 다양한 영향이 있을 수 있으나 가장 많은 영향을 주는 원인으로 토질 및 지질적인 조건이라고 할 수 있다. 본 논문은 이러한 지질조건에서 붕괴가 발생될 경우의 활동면에 대한 전단강도 추정하는 방법에 있어 역해석법에 의한 활동면의 전단강도 추정을 연구하였다 연구결과 붕괴된 사면에서 화성암은 마찰각 20$^{\circ}$~30$^{\circ}$, 점착력 0~2t/$m^2$의 범위를 가지며 퇴적암에서는 마찰각 $10^{\circ}$~17$^{\circ}$, 점착력 0~2.5t/$m^2$의 범위, 변성암에서는 마찰각 $10^{\circ}$~40$^{\circ}$, 점착력 0~4.0t/$m^2$의 범위가 우세한 것으로 나타났다. 그리고 지질구별 구분에 의하면, 절리에 의해 붕괴가 발생된 경우에는 마찰각 30$^{\circ}$~40$^{\circ}$, 점착력 0~3.5t/$m^2$, 엽리면은 마찰각 30$^{\circ}$~35$^{\circ}$, 점착력 0.5~3.0t/$m^2$, 단층면은 마찰각 11$^{\circ}$~38$^{\circ}$, 점착력 0~3.0t/$m^2$, 층리면은 마찰각 $10^{\circ}$~17$^{\circ}$, 점착력 0~2.5t/$m^2$ 정도의 범위를 갖는 것으로 나타났다.

• Journal of the Korean Geotechnical Society
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• v.27 no.1
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• pp.25-34
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• 2011

In general, many instrumentations of slope rely on theory or experience because on-site accessibility and long term instrumentation are difficult to conduct the instrumentation of slopes. Also the prediction of disaster is very difficult. Therefore experimental research was conducted about an effective method to predict collapse of slope and on-site applicability in this study. The collapse of slope was able to be predicted by applying AE sensor which we call WEAD to the failure criteria. The parameters of AE generated during the collapse of slope were secured through bending shear test. Test construction was applied to the slope with a history and a possibility of collapse. As a result, it is shown that AE parameters do not exceed the failure criterion and is found to be stable slopes. As the real symptoms of collapse did not appear, AE was found to have excellent applicability.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.775-784
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• 2009

Weathered foliation could act as a critical failure plane because this type of plane tend to have low roughness and long extensions. A big constructed slope at $\bigcirc\bigcirc$ road construction site was failed due to the block movement along a fault zone which is parallel to foliation. Tectonic activity reactivated a fault zone parallel to foliation, and the fault clay within the shear zone metamorphosed retrogressively to chrolite. The failed block moved when the block weigh lost the balancing with the resisting force of the retrogressively metamorphosed chrolite. Evaluating the three dimensional distribution of the foliation was critical for establishing a plan for the stabilization of the slope. For this purpose, 10 boreholes were drilled as a lattice distribution, and the BIPS analyses are performed at each boreholes. The fractures measured in the boreholes are projected into 15 cross sections and their distributions are analysed, using Fracjection software. The projection analyse show that the strike of the foliation gets dipper towards left side of the slope. This geometry indicates that there are more failure block geometry at left side of the slope. Potential failure planes are searched using the projection method, and these information are provided for further support design.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.417-427
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• 2017

This study aims to present cases of rock slope failures caused by geological structures. Status of slope failures, results of cause analysis and stabilizing methods are introduced, focusing primarily on rock slope failures caused by specific geologic structures, such as intersection of faults infilled with clay, foliation and fault shear zone by dike intrusion and deep-seated clayey layer along lithologic boundary. Detailed geological survey, geophysical exploration and boring survey were conducted for cause analysis. Stabilizing method to prevent further slope failures and to ensure long-term stability of slopes were established, considering characteristics of geological structures, types of failure and geological conditions.

• The Journal of Engineering Geology
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• v.12 no.1
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• pp.53-61
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• 2002

Cut-slope due to the road construction is one of the most significant problems in the domestic case, that is, 70% of the land is covered by mountain. Moreover, typhoons or heavy rains concentrated in summer season causes the failure of cut-slope. Rock-fall and soil slope failure take 40.8% and 29.5% out of the entire domestic cut-slope failure, respectively. Rock-fall is quickly occurred by the free fall or rolling of rock fragments generally in the upper slope. Soil slope failure produces a clastics-flow and increases casualty especially when caused by heave rainfall because the velocity of the movement is verb high. Considering the car speed and rock-fall velocity, it will take a life in a moment. This study analyzes a set of field data of most recently collapsed domestic road cut-slopes to characterize these cut-slopes and the nature of rock-falls and clastics flows at each site. Based on the results, design criteria for a road alarm system are proposed, considering the relationship between the time required for clastics-flow and the velocity and braking distance of a cat at the incidence. The road alarm system proposed herein would operate instantly after a rock-fall and it will minimize damages, by warning drivels approaching to the collapse or collapsing location in advance.

• The Journal of Engineering Geology
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• v.31 no.2
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• pp.179-186
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• 2021

Malpasset Dam, located in France, is of great importance in the field of civil and geotechnical engineering as it was the first arch dam that totally collapsed in 1959. A three-dimensional model of the dam was reconstructed using close-range photogrammetry technique. The orientations of foliation developed in the bedrock and the collapse surface were measured. Moreover, both model and measurement results showed high precision. The study result can be used in future studies such as collapse simulation analysis and geotechnical investigations.

• Journal of the Korean GEO-environmental Society
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• v.16 no.10
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• pp.23-32
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• 2015

Most studies on slope collapsed have focused on collapse cases that occur on stabilized slopes in public use. Few studies have been conducted on the collapse characteristics of slopes that occur during construction before stabilization of the slope. In this study, detailed investigation was conducted for 79 sites where slope collapse occurred during or immediately after construction in the Chungcheong region, and their geometrical characteristics, collapse characteristics, design and reinforcement methods were evaluated. As a result of this analysis, it was found that the Chungbuk (CB) area was marked by plane-type collapse and surface layer collapse whereas the Chungnam (CN) area was marked by surface layer collapse or loss of sedimentary rocks. Furthermore, the major collapse factors of the Chungbuk region were joint alternations (53%) and weathering (25%), and the blocking due to multidirectional joints and foliation was also an influencing factor. In the phyllite area, too, the development of joints (55%) was a major factor, but the geological characteristics (36%) of sedimentary rocks such as faults and coaly shale also had considerable effects. Therefore, the geological, climatic, and environment characteristics were found to have affected the stability of slopes.