• 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.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.37-46
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• 2013

Many factors about the stability for the reservoir embankments is determined when the facility is completed. Therefore the initial design of the embankment is important. Many researchers focused the effect of soil parameters although the cross section greatly affects the stability and can be controlled in design step. The objective of this research is to analysis of the effects for the safety factor of slope and seepage according to change cross-section in embankment. As a result, the quantity of seepage decreased as the gradient of downstream slope decreased and was proportional to the height of embankments. There was a linear relationship between the gradient of slope and the safety factor of slope. However the gradient of slope did not affect other side slope. All in a relationship, regressive equations with a high correlation coefficient were calculated and can be applied the simple estimation method of the stability using the cross-section. As results of analyzing the sensitivity, the friction angle and permeability critically effect for the slope stability and the seepage, respectively. The effect of the slope gradient was similar to major soil properties.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.649-654
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• 2005

Shallow slope failures in residual soil during periods of prolonged infiltration are common over the world. One of the key factors that dominate slope stability is hydrological response associated with infiltration. Hence, the soil-water profile during rainfall infiltration into unsaturated soil must me examined to evaluate slope stability. However, the hydraulic response of unsaturated soil is complicated by inherent uncertainties of the soil hydraulic properties. This study presents a methodology for assessing the effects of parameter uncertainty of hydraulic properties on the response of a analytical infiltration model using first-order reliability method. The unsaturated soil properties are considered as uncertain variables with means, standard deviations, and marginal probability distributions. Sensitivities of the probabilistic outcome to the basic uncertainties in the input random variables are provided through importance factors.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.27-36
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• 2013

LEM (Limit Equilibrium Method) based programs are commonly used for the designs of soil nailing as a slope reinforcement. However, there is a drawback that the interaction between ground and soil nailing is not properly reflected in those programs, which needs to be solved. For economical constructions and designs, research is also required on the support pattern of soil nailing. In this study, therefore, reinforcement effects of soil nailing were compared and analyzed by performing finite difference analyses which could properly consider the interaction between ground and soil nailing. As a result, when the angle from slope to nail is $90^{\circ}$, failure slip surface becomes the largest and thus the factor of safety becomes maximum.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1036-1041
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• 2008

In order to analysis the reason of sliding failure in embankment slope under construction in soft soil area, a model section located in Gimhae Region in Gyeongsangnam-Do, where the sliding failure had been occurred during embankment works in soft soil area, had been selected. This area had been firstly treated with the Pack Drain Method, and additional embankment works of 9.7 meters out of total 14 meters in thickness had been under construction. The results of analysis showed that the reason of sliding failure were overspeed in embankment construction and the overestimation of design factors in calculating strength of each layer of embankment and poor management and inaccuracy reading of measurement devices.

• 한국지형공간정보학회:학술대회논문집
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• 2005.08a
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• pp.61-72
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• 2005

The landslide risk assessment process consists of hazard risk assessment and vulnerability analysis. landslide hazard risk is location dependent. Therefore, maps and spatial technologies such as GIS are very important components of the risk assessment process. This paper discusses the advantages of using GIS technology in the risk assessment process and illustrates the benefits through case studies of live projects undertaken. The goal of this study is to generate a map of landslide vulnerability map by analysis of static natural factors with GIS. A simple and efficient algorithm is proposed to generate a landslide potentialities map from DEM and existing maps. The categories of controlling factors for landslides, aspect of slope, soil, vegetation are defined. The weight values for landslide potentialities are calculated from AHP method. Slope and slope-direction are extracted from DEM, and soil informations are extracted from digital soil map. Also, vegetation informations are extracted from digital vegetation map. Finally, as overlaying, landslide potentialities map is made out, and it is verified with landslide place.

• Geomechanics and Engineering
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• v.23 no.5
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• pp.481-491
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• 2020

Piles installed in row(s) are used as an effective technique to improve the stability of soil slopes. The analysis of pile-stabilized slopes require a reliable prediction of lateral resistance offered by the piles. In this work, an analytical solution is developed to estimate the lateral resistance offered by the stabilizing piles in sand and c - 𝜙 soil slopes considering soil arching phenomenon. The soil arching in both horizontal direction (between the neighboring piles) and vertical direction (in the active wedge in front of the pile row) are studied and their effects are incorporated in the proposed model. The shape of soil arch is assumed to be circular and principal stress trajectories are defined separately for both modes of arching. Experimental and numerical studies found in literature were used to validate the proposed method. A detailed parametric analysis was performed to study the influence of pile diameter, center-to-center spacing, slope angle and angle of internal friction on the lateral pile resistance.

• Journal of the Korean Geotechnical Society
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• v.32 no.1
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• pp.35-43
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• 2016

The time distribution of rainfall is one of the most important considerations for evaluating soil slope stability. In order to study the rainfall-induced slope failure, the rainfall pattern has generally been assumed as uniform rainfall intensity for rainfall duration. However, it should be noted that the time distribution of the design rainfall method has a significant effect on the soil slope instability. The study implemented Mononobe, Huff, and uniform method as three types of time distribution method of the design rainfall to estimate the factor of safety of soil slopes by rainfall duration. As a result, the difference of soil suction and unsaturated hydraulic properties in a soil by rainfall pattern was found through the application of an appropriate time distribution method to numerical simulation for rainfall-induced slope stability.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.862-869
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• 2005

This study examined 233 cut slopes in Gyeongnam region; evaluated hazards and slope conditions involved in the slope; and determined the priority order for reinforcement. The conclusions are summarized in the following. (1) The slopes that need reinforcement or maintenance are 153, accounting for 65.6% of the entire slopes. Slopes with a length of $0{\sim}200m$ account for 70.9%; slopes with a height of $10{\sim}20m$ account for over 50%. (2) Slopes with slope of more than 1:0.5 account for 70.9% of the entire slopes. The steepness of the slope is owing to more rock slopes than soil slopes. (3) The percentages of rock slopes, soil slopes, complex slopes mixed with rocks and soil, and slopes comprised of igneous rocks are 54.4%, 24.9%, 20.7%, and 54.1%, respectively. (4) In the rock area occurred cave-in, plain failure, wedge failure, and overturning failure, in order. Slopes with volcanic rocks are the most unstable, while sedimentary rocks and metamorphic rocks are relatively stable. (5) When the slope height is over 20m, low grade slopes are more than 80%; leading to the conclusion that the higher the slope height is, the more unstable the slope is.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.210-220
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• 2005

We have analyzed the stability for cut-slopes at main street 3-2 line section in Pa-ju local industrial complex. After studying an additional boring test, laboratory test and face mapping etc., we have determined the extent of reinforcement, slope inclinations and soil strength parameter from the analysis of test results. After changing the inclination of slopes for ground limit and carrying out the analysis of slope stability, we applied the Mass Nailing Method to the site because of need for reinforcement to soil and weathered rock slopes. In slope for soft and hard rock sections, we also reinforced the sections that are difficult to obtain the safety without reinforcement in alteration zone.