• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.257-264
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• 2001

This study presents the slope stability analysis results for the model slope test. The model slope was made of the soil reinforced by FPF(Fibrillated Polyprophylene Fiber). The shear strength properties of the soil reinforced by FPF fibers were evaluated through the direct shear tests. The model slope 1:1 and 1:1.5 were made and the load tests were performed. Back analysis using limit equilibrium method was carried out to evaluate the shear strength increase on the FPF reinforced slope. The factor of safety of the FPF reinforce slope increased about 23% over unreinforced slope.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.12
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• pp.903-910
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• 2003

A two-degree-of-freedom model is suggested to describe basic dynamical behaviors of the interaction between the pad and the disc of a disc brake system. Although a pad (and a disc) has many modes of vibration in practice, only one mode of each component Is considered. In this paper, a linear analysis is performed by means of the stability analysis to show various conditions for the system to become unstable, and is based on the assumption that the existence of limit cycle (this corresponds to an unstable equilibrium point inside the limit cycle) represents the squeal state of the disc brake system. The results of the stability analysis show that the damping of the disc is as much Important as that of the pad, whereas the damping of the pad only is considered In most practical situations.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.331-338
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• 1999

In the present study, a searching technique for critical slip surface in two dimensional slope stability analysis is proposed. The failure surface generation and analysis has been usually limited to simple geometric shapes. However, more random surfaces need to be examined for some particular ground conditions. For this purpose, random searching technique is developed using genetic algorithm. The generalized limit equilibrium method is employed as the method of stability analysis. Using this technique, the factor of safety is compared with the result by using simplified Bishop's method. In addition, the convergent trend of fitness value is analyzed.

• Tunnel and Underground Space
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• v.8 no.4
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• pp.287-295
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• 1998

Limit equilibrium method is widely used for the stability analysis of soil slopes. In jointed rock slopes however, the failure of the slope is largely dependent upon the strength and deformability of the joints in the rock mass and quite often failure occurs along the joints. This paper describes the use of ubiquitous joint model for the stability analysis of the jointed rock slopes. This model is essentially an anisotropic elasto-plastic model and can simulate two sets of joint in arbitrary orientations. Validation of the developed with the factor of safety equal to unity was selected when the shape of the failure plane is assumed log spiral. Then the factor of safety of the rock slope having two perpendicular joint sets was calculated while rotating joint orientations. Rusults were compared with limit equilibrium solutions on soil slopes having equivalent soil properties when plane sliding was assumed. Developed model predicted the factor of safety of jointed rock slope in a reasonable accuracy when joint spacing is sufficiently small.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.73-82
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• 2005

Generally, to evaluate a slope stability of the geosynthetic reinforced soil slope, the modified version of limit equilibrium method can be used. In most cases, resisting effects of reinforcement are dealt with considering an increased shear strength on the potential slip surface. However, it is not clear that the methods satisfy all three equilibrium equations. In this study, the new slope stability analysis method in which not only reinforcing effects of geosynthetics can be considered but also all three equilibrium equation can be satisfied is proposed. A number of illustrative examples, including published load test of large-scale reinforced retaining wall and centrifuge model tests on the geotextile reinforced soil slopes, are also analyzed. As a result, it is shown that the newly suggested method produces a relatively accurate factor of safety.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.2
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• pp.92-103
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• 1999

A series of field tests were performed to suggest a rational method for the stability evaluation of soft clay. The behavior of settlement-displacement obtained by field monitoring system was used to compare and analyze with various stability evaluation methods, and to investigate the applicability of the methods for stability evaluation of soft clay. The limit equilibrium method, numerical analysis and field monitoring methods were used to analyze the stability evaluation. The horizontal displacement was abruptly increased when physicla properties of soft clay reached its maximum values and therefore, the values of these properties could be used to the fundamental data for stability evaluation. The evaluation of the stability of clay embankment was suggested to use inclination of ccrve rather than critical line, and the minimum satey factor of 1.2 or larger for natural clay was recommeded . Therefore, the evaluation of short term stability of soft clay could be effectively peformed with the hypefrbolic model and the field monitored data.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.223-228
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• 2000

The current slope stability analysis of a filldam is based on the limit equilibrium method, and in calculation of safety factor during earthquake, adopts the seismic intensity method in which it considers a uniform seismic force from dam foundation to crest. However the observed behaviour of filldam during earthquake shows some different behaviour in that at the crest the measured acceleration is usually several times the ground acceleration. In this study, slope stability calculations of a filldam are provided based on the modified seismic intensity method, which can take into account the amplification phenomena of acceleration in the upper part of dam. And also the results of calculations are compared with that of current seismic intensity method.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.103-110
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• 2000

This paper deal with the stability evaluation and suggestion of progressive failure slope in biotite granite area of Andong. Based on geological site investigation and field test, stability analysis of slope was performed in conjunction with limit equilibrium methods and stereographic projection. Additionally, initial design and construction procedure was critically evaluated. Series of the slope stability analysis reveals the detection of local wedge and plane failure under the current slope condition. It is additionally appeared that a certain synthetic behavior of circle and plane failure exists on the right spot where the overall failure's going in progress. In order to construct more stable slope based on the suitability for the real state of the slope circumstances, this study issues a solution to eliminate the primary factors which cause the instability, by means of the grade of weathering and RMR classification of rock mass.

• Journal of the Korean Society of Safety
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• v.22 no.3 s.81
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• pp.74-80
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• 2007

In this study, a documentary survey, face mapping, and stability analysis were performed on the collapsed colluvial soil slope. The purpose of this paper is to identify the cause of slope failure and determine slope stability for similar areas. Boring samples were extracted from the slump and laboratory tests were performed to find out the cause of slope failure. In addition, the limit equilibrium method was used in order to determine the stability of the slope. As a result of this investigation and the analysis of data, the type of collapse and cause of slope failure have been shown to have a strong correlation with the natural geographical and geological features which make up the collapse profile of the study area. These results will help to develop guidelines for formulating countermeasure methods.

• Journal of the Korean Geotechnical Society
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• v.30 no.11
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• pp.5-15
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• 2014

It is very important to design and construct slopes safely because damage cases are increasing due to slope failure. Recently, Limit Equilibrium Method (LEM) based programs are commonly used for slope designs. Though LEM can give factors of safety through simple calculation, it has a disadvantage that the sliding surface should be assumed in advance. On the other hand, the use of Finite Difference Method (FDM) is increasing since the factor of safety can be easily estimated by using shear strength reduction technique. Therefore the purpose of this study is to present a reasonable slope design methodology by comparing the two commonly used analysis approaches; LEM and FDM. To this end, the reinforcement effects of the two methods were compared in terms of the support pattern of soil nailing reinforced in the section where plane failure is anticipated. As a result, the reinforcement effects by nail angle and nail spacing turned out to be equal. Also it was found that the factor of safety increased in LEM, but not changed in FDM when the nail length increased.