• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.101-110
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• 1995

The use of geotextile as reinforced materials in Soil structures has become widespread throughout the world. Geotextile reinforcement has been used in retaining walls, slope of embankment and especially soft foundation, etc. In the past, however, its design and construction have been performed empirically. In this study, to investigate of the effect of geotextiles reinforced slope of the embankment on a very soft foundation, a limit equilibrium analysis program calculating the safety factor of embankment on very soft foundation was developed. The study was focussed on such factors as type of geotextile, tensile strength, amount of reinforcement, and inclination of embankment. And the 4imit equilibrium analysis program was written on the basis of Low's slope stability theory with some modification. The following conclusions were drawn from this study. (1) The orientation of reinforcement can be assumed either horizontal or tangential to the slip circle. The factor of safety with tangential reinforcement is larger than that with the horizontal reinforcement. (2) In general, the factor of safety increases, as the slope reduces. However, it is preferable to use geotextiles with higher tensile strength rather than to reduce the slope of the embankment, because it is difficult to adjust the slope as desired. (3) The factor of safety obtained by numerical computation is affected only by the tensile strength, but not by the type of the geotextile.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.277-284
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• 1999

This study describes the influence factors related to slope failure pattern and dimension in the southern Kyounggi area. Intrusive and metamorphic rocks are distributed in the study area. Geological condition, rainfall property and slope geometry are influence on slope failure characteristics in the study we& Geological factors related to slope failure are rock type, geological structure and weathering condition. Because of deep soil (RS-CW) depth of granite region, circular failure type is major failure pattern in granite region. Almost granite slopes with circular or surface failure pattern are failed during heavy rainfall season. But typical wedge failure type related to geological structure factor is a main failure pattern of metamorphic rock slope. Additionally failure dimension is influenced by geological factors and several factors, i.e. natural slope condition, failure type, rainfall intensity and etc. failure height/width ratio and thickness/length ratio of granite slope are 0.88 and 0.23. But the ratios of metamorphic rock slope are 1.36 and 0.19.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.513-520
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• 2003

A numerical comparison or predictions by limit equilibrium analysis and 3n analysis is presented for slope/pile system. Special attention is given to the coupled analysis based on the explicit-finite-difference code, FLAC. To this end, an internal routine (FISH) was developed to calculate a factor of safety for a pile-reinforced slope according to shear strength reduction technique. The case of coupled analyses was performed for stabilizing piles in slope in which the pile response and slope stability are considered simultaneously and subsequently the factors of safety are compared to uncoupled analysis (limit equilibrium analysis) solution for a homogeneous slope. Based on a limited parametric study, it is shown that in the free-head condition the factor of safety in slope is more conservative for a coupled analysis than for an uncoupled analysis and a definitely larger value represents when piles are installed in the middle of the slopes and are restrained in the pile head.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.339-344
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• 2006

Slope failures are happen to natural disastrous when they occur in mountainous areas adjoining highways in Korea. The accidents associated with slope failures have increased due to rapid urbanization of mountainous areas. Therefore, Regular maintenance is essential for all slope and conducted to maintain road safety as well as road function. In this study, we take priority of making a database of risk factor of the failure of a slope before assesment and analysis. The purpose of this paper is to recommend a standard of Slope Management Information Sheet(SMIS) like as Hazard Map. The next research, we suggest to pre-estimated model of a road slope using Logistic Regression Model.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.697-702
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• 2006

A counterplan of slope failure has to investigate about various and engineering safety factors. Especially, it is important that large cut-slope must examine rational and economic solution. In this case study, cut-slope failure caused by inflow of rainwater into alternate layers. Hereafter it is suggested that large cut-slope should consider analysis the cause for a decline of safety factor and the engineering character of corestone ground mass.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.73-81
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• 2006

A sensitivity analysis about effects of influencing factors on the stability of Soil cut slope was performed. Slope stability analyses were carried out under dry, rainy and seismic conditions. Dominant factors controlling the slope stability were chosen such as cohesion and internal friction angle, unit weight of soil, water table and seismic horizontal coefficient used for the slope stability during earthquake. Parametric stability analysis with those factors was performed for sensitivity analysis. As results of analyzing the sensitivity of factors under dry and rainy conditions, effects of cohesion, internal friction angle and unit weight of soil on the stability of slope are more critical in the dry condition than in the rainy condition. Cohesion and internal friction angle are more dominant factors influencing the slope stability irrespective of dry or rainy conditions than unit weight of soil and the horizontal seismic coefficient. The unit weight and the horizontal seismic coefficient affects crucially the stability according to conditions of slope formation and dry or rainy seasons. For the effect of horizontal seismic coefficient on stability of slope, safety factor of slope is not affected significantly by dry or rainy conditions. However, increase of the horizontal seismic coefficient under the rainy condition floes reduce the safety factor significantly rather than the dry condition. Therefore, it is needed that the location of the water table is assigned appropriately to satisfy the required safety factor of stability in the case of checking slope stability for the rainy and seismic conditions.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.75-82
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• 2005

Shear strength parameters obtained from field tests are important factors in the analysis of slope stability. In this paper, sensitivity analysis was performed to evaluate the effect of input parameters on the analysis of slope stability. The input parameters selected for sensitivity analysis were slope angle, cohesion, and friction angle. Monte-Carlo Simulation method was to estimate input parameters for sensitivity analysis in slope stability, and the limit equilibrium method was used to calculate the factor of safety of slope stability. A rock slope, failed in the field, was used for the sensitivity analysis of input parameters in the analysis of slope stability. The result of analysis shows that the factor of safety of the rock slope was a little low. From partial correlation coefficient (PCC) of input parameters from the sensitivity analysis, slope stability was dependant mainly on cohesion and slope angle. The effect of friction angle was smaller than those of cohesion and slope angle on slope stability.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.6
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• pp.55-65
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• 2019

Universal Soil Loss Equation (USLE) is to estimate potential soil loss and has benefit in use with its simplicity. The equation is composed of five factors, one of the factors is the slope length and steepness factor (LS factor) that is for topographic property of fields to estimate potential soil loss. Since the USLE was developed, many equations to compute LS was suggested with field measurement. Nowadays the factor is often computed in GIS software with digital elevation model, however it was reported that the factor is very sensitive to the resolution of digital elevation model. In addition, the digital elevation model of high resolution less than 3 meter is required in small field application, however these inputs are not associate with the empirical models' backgrounds since the empirical models were derived in 22.1 meter field measurements. In the study, four equation to compute LS factor and two approaches to determine slope length and steepness were examined, and correction factor was suggested to provide reasonable precision in LS estimations. The correction factor is computed with field area and cell size of digital elevation model, thus the correction factor can be adapted in any USLE-based models using LS factor at field level.

• Journal of the Korean Geotechnical Society
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• v.20 no.8
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• pp.97-102
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• 2004

In this paper, a finite element based method far determining factor of safety of slopes which has certain advantages over conventional limit equilibrium methods is described. Particularly, the slope failure behaviour considering different seepage conditions is produced by finite element method using strength reduction technique. It is shown that both the failure mechanism and the safety factor that are analyzed by the FEM using strength reduction technique are an effective means of slope stability analysis. And the stability of a slope with rising water table and rapid drawdown are analyzed and the results are compared with the simplified Bishop Method of the Limit Equilibrium Methods.

• Journal of the Korean Geotechnical Society
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• v.31 no.1
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• pp.47-52
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• 2015

In the slope stability analysis and design, Limit Equilibrium Method (LEM) and Shear Strength Reduction technique (SSR) are mainly used. Both methods are able to perform two and three dimensional analysis. SSR is considered to be more sensitive and more reasonable than LEM by many researchers. However, in practice LEM is still widely used because of the increase of analysis time and complexity of the model in SSR. In this study, three dimensional analysis of the protruding rock slope is performed by SSR in order to study the effects of protruding length using rock slope FLAC 3D. In this study, as results of analysis variations of the safety factor have been studied according to slope angle, slope height, the soil strength, protruding slope length projected variables. The results show that the factor of safety as more affected by the shapes of the protruding rock slope than the rock strength.