• Geomechanics and Engineering
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• 제15권4호
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• pp.947-955
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• 2018

In this study, we propose a three-dimensional simplified slope stability analysis using a hybrid-type penalty method (HPM). In this method, a solid element obtained by the HPM is applied to a column that divides the slope into a lattice. Therefore, it can obtain a safety factor in the same way as simplified methods on the slip surface. Furthermore, it can obtain results (displacement and strain) that cannot be obtained by conventional limit equilibrium methods such as the Hovland method. The continuity condition of displacement between adjacent columns and between elements for each depth is considered to incorporate a penalty function and the relative displacement. For a slip surface between the bottom surface and the boundary condition to express the slip of slope, we introduce a penalty function based on the Mohr-Coulomb failure criterion. To compute the state of the slip surface, an r-min method is used in the load incremental method. Using the result of the simple three-dimensional slope stability analysis, we obtain a safety factor that is the same as the conventional method. Furthermore, the movement of the slope was calculated quantitatively and qualitatively because the displacement and strain of each element are obtained.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 사면안정학술발표회
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• pp.129-144
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• 2003

Generally, investigation methods of cut slope are conducted 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.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.1060-1067
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• 2009

Previous research on the slope failure has mainly reported that most of the slope failures occur due to surface rainfall infiltration in the rainy season. A slope of which surface is protected by shotcrete or plants, can also fail due to increase in pore water pressure from the ground water flow beneath the surface, rather than from the surface. In this study such case of slope behavior is investigated using the model test and numerical method including strength reduction method. Hydraulic boundary conditions of the slopes is considered using coupled numerical scheme. The failure mechanism of the slope is investigated and the effect of pore water pressure on slope safety is identified. Increase in pore water pressure due to lateral infiltration has significantly reduced the stability of slope.

• 한국구조물진단유지관리공학회 논문집
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• 제4권1호
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• pp.101-110
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• 2000

In case heavy rainfall is a key factor of slope failure, the failure zone is usually developed within the depth of 3~5m from the ground surface regardless of the location of the watertable. If rainfall is taken into consideration, it is general that the slope stability analysis is carried out under the assumption that the cut slope is saturated to the slope surface or the watertable elevates to a certain height so that ${\gamma}_{sat}$, the unit weight of saturated soil, is used. However, the analysis method mentioned above can't exactly simulate the variation of pore water pressure in the slope and yields different failure shape. The applicability of slope stability analysis method considering the distribution of pore water pressure within the slope with heavy rainfalls, was checked out after the stability analysis of a lage-scale cut slope in a highway construction site, where surface failure occurred with heavy rainfalls. An appropriate slope stabilization method is proposed on the base of the outcome of the analysis.

• 한국환경과학회지
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• 제13권9호
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• pp.759-765
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• 2004

HEC-RAS model is used for estimation of rating-curve of Musung in Wi stream. Discharge is computed from stage estimated by HEC-RAS model, is compared with the discharge of water surface slope method. The relative deviation of observed and computed discharge is 5.37%, and shows as a good results. A rating-curve by HEC-RAS model shows better results than by water surface slope method.

• 한국지반공학회논문집
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• 제15권3호
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• pp.27-40
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• 1999

사면안정해석을 수행하기 위하여 많이 사용하는 한계평형방법은 일정한 가정을 하여 안전율을 평형에 필요한 응력과 흙의 전단강도의 비로 정의하여 대상사면의 안전율을 구한다. 유한요소법을 이용한 사면안정해석방법은 응력상태를 유한요소법으로 구한 후 원호나 대수나선형등의 일정한 모양의 사면 파괴선을 가정하여 반복적으로 최소안전율을 구한다. 본 연구에서는 유한요소법을 이용한 사면안정해석방법을 개발하여 사면의 가장 취약한 부분을 따라 파괴선이 발생하도록 하였다. 이것은 요소내의 국부안전율과 파괴각을 고려하여 사면파괴선을 자동적으로 구할 수 있도록 함으로써 가능한데 이 방법은 임의의 파괴선을 가정할 필요가 없으며 절편에 작용하는 힘에 대하여 가정을 할 필요가 없고 임의의 모양의 파괴선을 구할 수 있는 장점이 있다. 본 연구에서는 개발된 해석방법을 검증하기 위하여 가상의 사면, 자연사면, 그리고 댐사면에 적용하여 실무에서 많이 사용하는 한계평형방법 프로그램인 STABL5M과 SLOPE/W과 비교 평가하였다.

• Geomechanics and Engineering
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• 제34권2호
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• pp.187-195
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• 2023

Intensive rainfall during the summer season in Korea has triggered numerous devastating landslides outside of downtown in mountainous areas. The 2D slope stability analysis that is generally used for cut slopes and embankments is inadequate to model slope failure in mountainous areas. This paper presents a new 3D slope stability formulation using the global sliding vector in the limit equilibrium method, and it uses an ellipsoidal slip surface for static and quasi-static analyses. The slip surface's flexibility of the ellipsoid shape gives a lower FS than the spherical failure shape in the Fellenius, Bishop, and Janbu's simplified methods. The increasing sub-columns of each column tend to increase the FS and converge to a steady value. The symmetrical geometric conditions of the convex turning corners do not indicate symmetrical failure of the surface in 3D analysis. Pseudo-static analysis shows that the horizontal seismic force decreases the FS and increases the mass volume at the critical failure state. The stability index takes the FS and corresponding sliding mass into consideration to assess the potential risk of slope failure in complex mountainous terrain. It is a valuable parameter for selecting a vulnerable area and evaluating the overall risk of slope failure.

• 한국환경복원기술학회지
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• 제4권3호
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• pp.10-18
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• 2001

The existing measurement system to ground-surface displacement survey of the slope has been including the hazard for the measure in site and the difficulty for install, maintenance and control of expensive instruments, which are impossible of whole survey on the slope surface. To overcome of those defects, Softcopy Photogrammertry method is used, which can measure displacement of ground-surface on the slope and structure deformation vectors. Recently, the survey methods applying the advantages of Photogrammetry and Digital Photogrammetry Survey are widely used. In this study, therefore, the development and application of the new instrument mechanism on the the site example are studied. Through the application of Softcopy Photogrammetry, the 3-D data of ground surface on the dangerous slope could be effectively obtained at the long distance, which are obtained through the reform process of contour line. Those are different to the results of the Close-Range Photogrammetry analysis. In ground instrumentation parts, the new practical system shall be the technical base to improve of the instrument machine as well as can be widely applied in civil engineering and others branch.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 1999년도 제2회 학술발표회
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• pp.217-239
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• 1999

일반적으로 사면에 대한 조사방법은 지표지질조사를 실시하여 불연속면의 정보를 획득하는 것이 보편화 된 방법이나 제한된 영역의 정보만을 획득하게 되는 문제점을 가지게 된다. 일반적으로 절취사면에서 활동면 또는 활동가능면을 추정하는 방법으로 토모그래피, 전기비저항탐사, 탄성파 탐사와 같은 지구물리탐사 방법을 이용하나 최근에 사용된 카메라 장치를 이용하는 방법은 시추공벽의 화상을 촬영하여 직접 육안으로 확인 할 수 있는 방법으로 다른 방법들에 비해 보다 확실한 방법이라고 생각된다. 그러므로 본 논문은 고속도로 현장에서 붕괴가 발생된 사면의 활동면 위치를 파악하기 위해 총 4 개공의 시추를 실시하였고 BIPS(Borehole Image Processing System) 장비를 도입하여 활동면의 위치를 파악하였다. 그 결과, 철탑구간은 지표에서 20m 하부구간까지 암질이 매우 불량하고 점토층이 충전된 파쇄대층이 존재하고 철탑좌측구간은 이미 인장균열이 발생되었으며 점토층이 충전된 층리면 존재하고 층리면은 사면방향으로 경사져 붕괴가능성이 클 것으로 나타났다. BIPS 결과는 사면안정대책 방안에 수립하는 데 이용하여 억지말뚝으로 사면보강공을 선정하였다.

• 한국정밀공학회지
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• 제13권9호
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• pp.38-45
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• 1996

The optical triangulation method has been used as a non-contact measuring method of three dimensional object whape. But this measuring method has narrow measuring range, non-linearity on steep slope surface and shadow effect. In this study, we discussed a new optical measurement method to overcome these kinds of demerits. The advantage of this new method is that it is possible to measure precisely the object shape having the steep slope surface without shadow effect. As exper- imental results, maximum displacement error was 200 .mu. m over the whole measuring when the incident angle on the object surface was within 60 degree.