• Title/Summary/Keyword: Slope safety factor

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The Computation of Reinforcement Length of Afforestation Slope (사면녹화 보강토공법의 보강재길이 산정에 관한 연구)

  • Park, Sik-Choon;Nam, Kwang-On;Kim, Jong-Hwan;Lee, Soo-Yang
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1302-1308
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    • 2010
  • This study the change of the safety factor before and after the reinforcement were compared by performing the parameter research based on the limit equilibrium analysis regarding the same cross section after carrying out the safety factor before the reinforcement on the virtual section in order to observe the change of the safety factor of the slop reinforced with the slope planting reinforced earth, and the variation of the safety factor according to the increase of the length of the reinforcement materials and the change of the slope height was analyzed. As the result, the reinforcement effect was insignificant at no more than 0.6 of L/H, the reinforcement length ratio when the reinforcement length was increased, as the increase of the safety factor was slow comparing with the non-reinforced slope. At 3.0m of the slope height, reinforcement on the slope is not necessary, and at 3.0m to 5.0m of the slope height, the inclination was not influencing at no less than 0.6 of L/H. At 5.0m to 9.0m of the slope height, the safety factor was mostly secured on the slope at 0.8 of L/H and the over-reinforced slope appeared at no less than 1.0 of L/H. Also, the safety factor increased as the slope height increases and the slope gets steeper till 0.8 of L/H, but the slope steepness affects more on the increase of the safety factor than the reinforcement material, as the reinforcing force by the reinforcement material became steady.

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A Study of Limit State Design Method in Soil Slope (토사면의 한계상태 설계법에 관한 연구)

  • Joung, Gi-Hun;Kim, Jong-Min;Jang, Bum-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.129-136
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    • 2005
  • The deterministic analysis method has generally used to evaluate the slope stability and it evaluates the slope stability with decision value that is a representative value of design variables. However, one of disadvantages in the deterministic approach is there is not able to consider the uncertainty of soil strength properties, even though it is the biggest influential parameter of the slope stability. On the other hand, the limit state design(LSD) can take a consideration of uncertainties and computes both the reliability index and the probability of failure. LSD method is capable of overcoming the disadvantages of deterministic method and evaluating the slope stability more reliably. In this study, both the mean value and standard deviation of the internal land's representative soil strength properties applied to process the LSD method. The major purpose of this study is to gauge the general applicability of the limit state design in soil slope and to weigh the comparative validity of the proposed partial safety factor. In order to reach the aim of this study, the partial safety factor and resistance factor which totally satisfied the slope's overall safety factor were calculated by the load and resistance safety factor design (LRFD).

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Stability Analysis of the Slopes (사면의 안정해석에 관한 연구)

  • 강우욱;조성섭;지인택
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.31 no.1
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    • pp.58-70
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    • 1989
  • The paper compared the Bishop methed to the Fellenius method in the analysis of slope stability. Laboratory model test was carried out in the case of seepage flow considered. The results obtained from this study were summarized as follows; 1. The slice pieces of 10 were enough to analysis the slope stability. 2. The safety factor. by the Fellenius method was lower than the Bishop method by the 96 to 97% in the case of no seepage flow and by the 95 to 96% in the case of seepage flow considered. 3. Besides the parameter of soil and slope, the safety factor of slope was influenced by the height of slope. This phenomena was distinct in the height of height less than 10 meters. 4. In the case of clay, there was no difference in the safety factor of slope between Fellenius and Bishop rnethod. The safety factors of slope with the seepage flow considered were lower than those with no see-page flow. 5. The influence of cohesion on the safety factor was more significant in the Bishop method than in the Fellenius method. 6. The slope failure of model test of A and B soil samples with high permeability coefficient was taken place slightly in vicinity of toe by the concentration of stress and gradually increased 7. Under condition of same slope height, the shapper the slope, the shorter the radius and the center of critical circle appered downward and finally failure of slope occured inside the slope.

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A Study on Reinforcement for Slope Stability of Gentle Inclination Slope Collapse Occurrence Area (완경사 사면붕괴 지역의 안전성 보강대책 연구)

  • 이승호;황영철;조성민;노흥제;이은동
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.83-91
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    • 2003
  • Always slope according to construct road exist danger because of environment unstability factor in slope, Since this research an inclination of slope is gentle slope (1:1.5∼1:9.0) but falling happened by conduct of continuous ground movement. And this study considered more economical and efficient reinforcement method for slope stability. The various reinforcement methods are applied to execute examination of slope stability. Applied reinforcement methods satisfied safety factor And this research region is performing continuous measurement about ground movements and displacements.

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A Study on the Variation of Ground Safety Factor by Earthworks

  • Kim, Jinhwan;Kwon, O-Il;Baek, Yong;Kim, Chang-Yong
    • The Journal of Engineering Geology
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    • v.24 no.3
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    • pp.333-341
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    • 2014
  • The construction of roads, tunnels, and bridges results in changes to the local terrain that may influence the ground safety factor, which represents the stability of geotechnical structures. In this study, we assessed construction sites that had collapsed as a result of terrain change, and then simulated variation in the ground safety factor with respect to terrain change caused by road construction. We assumed steep slopes to simulate changes in terrain in a mountainous area and assumed that earthworks took place for road construction by cutting a platform into the slope and altering the slope angle of the terrain both above and below the road. We calculated values of the ground safety factor through a stability analysis of the slope both above and below the road, and examined the variation in the safety factor of the above- and below-road slopes with respect to changes in road width. We found that if the slope angle was the same above and below the road, then the change in the ground safety factor during/after road construction occurred in the slope below the road, and if the slope angle above the road differed from that below, then the change occurred in both the above- and below-road slopes. Furthermore, the ground safety factor was essentially constant for road widths exceeding 2-6 m, depending on both above- and below-road slope angle. The findings of this study can be used to guide the management of construction sites and to assess changes in ground stability during road construction work, particularly in the early stages of earthworks, when the road width is narrow.

A Study on Effect of Stabilizing Pile on Stability of Infinite Slope (무한사면의 안정성에 미치는 억지말뚝의 영향에 대한 이론적 연구)

  • Lee, Seung-Hyun;Lee, Su-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.12
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    • pp.496-503
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    • 2016
  • To analyze an infinite slope that is reinforced with stabilizing piles, the forces on the stabilizing pile were estimated by the theory of plastic deformation and the theory of plastic flow and the effects of diverse factors on the factor of safety of an infinite slope were investigated. According to the results of the analyses, the factor of the safety of the slope reinforced with stabilized piles were increased tremendously and the factor of safety decreased as the center to center distance of the stabilizing pile increased. The effect of the existence of seepage of the infinite slope with stabilizing piles on the factor of safety appears to be insignificant. Considering the formulated factor of safety of an infinite slope with stabilizing piles, the width and length of the element of the infinite slope and force on the stabilizing pile influence the factor of safety of the infinite slope with a stabilizing pile including the soil strength parameter, inclination of the slope and depth of the slope, which are important for calculating the factor of safety of a non-reinforced infinite slope. The factor of safety of an infinite slope with stabilizing piles derived from the theory of plastic deformation were increased significantly with the internal friction angle of the soil, and the minimum and the maximum factor of safety under the conditions considered in this study were 13.7 and 65.6, respectively. As the diameter of the stabilizing pile increased, the forces on the stabilizing pile also increased but the factor of safety of the infinite slope with stabilizing piles decreased due to the effects of the width and the length of the element of the infinite slope. The factor of safety of the infinite slope with stabilizing piles derived from plastic flow were much larger than that of the non-reinforced infinite slope and the factor safety of the infinite slope with a stabilizing pile increased with increasing product of the flow velocity and plastic viscosity ( ) and the factor of safety of the infinite slope with stabilizing piles decreased with increasing center to center distance of the pile.

Analysis for the Safety Factor of Slope and Seepage according to Change Cross-Section in the Reservoir Embankments (저수지 제체 단면 형상 변화에 따른 안전율 및 침투유량 분석)

  • Noh, Soo-Kack;Son, Young-Hwan;Bong, Tae-Ho;Park, Jae-Sung;Choi, Woo-Seok
    • 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.

A case study of slope failure for large cut-slope (대절토사면내 붕괴발생에 따른 안정성검토 사례연구)

  • Lee, Yeon-Hee;Shin, Chang-Gun;Kim, Yong-Soo;Han, Jae-Hee;Choi, Jun-Il
    • 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.

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Consideration of Minimum Safety Factors for Cut-slope Infiltration Analysis (깎기비탈면 침투해석을 위한 최소 안전율 적용성 고찰)

  • Lee, Jeong-Yeob;Rhee, Jong-Hyun;Oak, Young-Suk;Koo, Ho-Bon
    • The Journal of Engineering Geology
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    • v.22 no.4
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    • pp.375-385
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    • 2012
  • Infiltration characteristics of cut-slope safety factors are considered for precipitation duration and intensity. Infiltration characteristics (infiltration module) and safety factor (slope module) changes of a cut-slope are analyzed under various conditions of precipitation intensity and duration, using the Soilworks program. The results indicate that the addition safety factors of the slope decreased immediately after the end of precipitation due to an increase in pore water pressure. The minimum safety factor for cut-slope infiltration analysis should be considered because of the because of the decrement of safety factors after precipitation that exceeds the decrement of safety factor during the duration of precipitation.