• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.457-464
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• 2016

The analysis for stability of slope reinforced with soil nails need professional knowledge and skilled technology for program. So we spend a lot of money and time. In this study, we try to save it. After we analyzed the stability of reinforced slope with MIDAS GTS using shear strength reduction technique, we made charts by result. Charts created in the stydy can be used rapidly in slope disaster prevention. We try to analyze stability of slopes when we changed nail spacing, nail angle, slope type, properties of soil. We obtained relationship as follows; 1) The safety factor appears effectively when the nail angle is $10{\sim}20^{\circ}$. 2) The safety factor appears effectively when the nail spacing is 0.8~1.2m. 3) The error of Singh's and suggested chart are 3.45, 8.65, 4.35% when the slope are 1:0.5, 1:1, 1:2.

• Geomechanics and Engineering
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• v.14 no.1
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• pp.71-81
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• 2018

Soils are mostly nonhomogeneous and anisotropic in nature. In this study, nonhomogeneity and anisotropy of soil are taken into consideration by assuming that the cohesion increases with depth linearly and also varies with respect to direction at a particular point. A three-dimensional rotational failure mechanism is adopted, and then a three-dimensional stability analysis of slope is carried out with the failure surface in the shape of a curvilinear cone in virtue of the limit analysis method. A quasistatic approach is used to develop stability charts in nonhomogeneous and anisotropic soils. One can easily read the safety factors from the charts without the need for iterative procedures for safety factors calculation. The charts are of practical importance to prevent a plane failure in excavation slope whether it is physically constrained or not. Then the most suitable location of piles within the reinforced slope in nonhomogeneous and anisotropic soils is explored, as well as the interactions of nonhomogeneous and anisotropic coefficients on pile reinforcement effects. The results indicate that piles are more effective when they are located between the middle and the crest of the slope, and the nonhomogeneous coefficient as well as the anisotropic coefficient will not only influence the most suitable location for piles but also affect the calculated safety factor of existing reinforced slope. In addition, the two coefficients will interact with each other on the effect on slope reinforcement.

• Journal of Korean Society of societal Security
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• v.4 no.1
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• pp.67-74
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• 2011

This paper was to examine the causes of steep slope failure during the season of heavy rainfall. For the purpose, the paper carefully analyzed the sites of steep slope failure, which happened in July 2009. The direct cause of steep slope failure was much related to heavy rainfall during summer. The paper continued to verify that additional causes include the malfunction of diverse waterways, the slope design without considering weathering soils and related characteristics, the lack of the waterway size, the intrusion of plant roots, the reinforced technique without considering slope conditions, etc.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.17-26
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• 2008

In this study, the design method of slope reinforced by the earth retention systems were systematically developed, and the flow chart of design procedure fur each system were constructed to design the slope rationally. The proposed design method is composed of 5 steps such as field condition investigation step, slope design step, landslide occurrence prediction step, slope failure scale estimation step and reinforcement countermeasure selection step. The quantitative standard of slope failure scale was established based on the arrangement of various overseas standards which is estimating the slope failure, and the analysis of slope failure scale which is occurred in the country. The slope failure scale is classified into three categories the small scale of slope failure is less than $150m^3$ of slope failure volume, the middle scale of slope failure is from $150m^3$ to $900m^3$ and the large scale of slope failure is more than $900m^3$. The earth retention system could be selected by the proposed slope failure scale based on the slope failure volume. Meanwhile, the design methods of earth retention system such as piles, soil nails and anchors were developed. The optimal countermeasure for slope stability could be proposed using above design methods.

• 도로교통
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• s.87
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• pp.56-63
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• 2002

• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.67-72
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• 2008

To confirm the stability of a cut slope in the road extension construction site, several investigations were carried out and countermeasures of slope was studied. This paper describes a study of design case of extra reinforcement on existing cut slope reinforced by preloading and piles in roads. To investigate the effect of stabilizing piles installed in a cut slope, an instrumentation system also designed, was. As a result that the stabilizing file and earth anchor are considered as the extra reinforcement, both stabilizing pile and earth anchor guarantee the stability of cut slope. However, stabilizing pile is selected in aspects of economy and continuity to the existing cut slop reinforcement including counterweight fill and stabilizing piles.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.955-962
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• 2008

This study concerns the effect of drainage in reinforced soil on its stability during rainfall. A series of finite-element analysis based transient seepage analysis were performed on a number of cases with different drainage conditions in terms of layers of geotextiles installed in the reinforced zone. The results were then coupled with the limit-equilibrium slope stability analysis to investigate the variation of global stability factor of safety with rainfall infiltration into the reinforced wall. The results were thoroughly analyzed to get insight into the mechanism of pore water pressure reduction effect of the geotextile and into its effect on overall slope stability. It is shown that layers of geotextile installed in the reinforced zone can prevent decrease in suction in the reinforced zone during rainfall, thereby reducing potential risk of decreasing shear strength of the reinforced zone. Practical implications of the findings were discussed.

• Journal of the Korean Geosynthetics Society
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• v.8 no.3
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• pp.17-23
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• 2009

Conventional methods of reinforced slope analysis based on the concept of limit equilibrium have been widely adopted mainly due to their simplicity and short computation time. But depending upon the assumptions on the inter-slice forces, the factor of safety resulting from the limit equilibrium method is not uniquely determined. This paper describes a method to calculate the factor of safely of a slope using a numerical analysis. Recently some useful analysis techniques (Strength reduction method and the stability method using stress fields) by numerical analysis are proposed and their theory and characteristics applications are studied and investigated with simple examples in this paper.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.3
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• pp.15-22
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• 2002

To analysis of the embanked slope stability using a jointed reinforcement, the internal stability and the external stability have to be satisfied, respectively. But, because the lengths of ready-made steel-grid were limited, the reinforcements must be connecting themselves to the reinforcing. In this study, the mechanical test was carried out to investigate the tensile failure and the pullout failure at the joint parts of them, which was based on the analysis of reinforced slope in field. Through the tensile tests in mid-air for the jointed steel-grid, the deformation behavior was seriously observed as follows : deformation of longitudinal member, plastic deformation of longitudinal member and of crank part. Those effects were due to the confining pressure and overburden pressure of the surrounding ground. The bearing resistance at jointed part of jointed steel-grid was due to the latter only. The maximum tensile forces were higher about 20kN~27kN than ultimate pullout resistance, but, the results of those was almost the same in mid-soil. The failures of steel-grid occurred at welded point both of longitudinal members and transverse members and of jointed parts. The strength of jointed parts itself got pullout force about 20kN, which was about 65% for ultimate pullout force of the longitudinal members N=2. To the stability analysis of reinforced structure including the reinforced slope, the studying of connection effects at jointed part of reinforcement members must be considered. Through the results of them, the stability of reinforced structures should be satisfied.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.128-131
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• 2001

The purpose of this study is to investigate the application of Column Jet Method(CJM) as countermeasure against settlement and slope sliding of existing marine structure due to embankment load behind reclaimed revetment. CJM is to make high-strengthened body by compacting and grouting cement mortar after forming artificial space in the ground with ground relaxition machine or high pressure water jetting. Before the ground was reinforced by CJM, the result of slope stability analysis was not satisfy the allowable safe ratio, but after the ground was reinforced by CJM, the stability of slope was over the allowable safe ratio and stable, Therefor, the application of CJM to restraint settlement and sliding of marine structure was very satisfactory.