• Structural Engineering and Mechanics
• /
• v.89 no.3
• /
• pp.253-263
• /
• 2024

Slope stability is generally paid more attention to in slope protection works, especially for slope containing weak layers. Two indexes of safety factor and failure model are selected to perform slope stability. Moreover, the finite element limit analysis method comprehensively combines the advantage of the limit analysis method and the finite element method obtaining the upper and lower bounds of the safety factor and the failure mode under the slope stability limit state. In this study, taking a waste dump containing a weak layer as an engineering background, the finite element limit analysis method is adopted to explore the potential failure mode. Meanwhile, the sensitivity analysis of slope stability is performed on geometrical and geotechnical parameters of the waste dump. The results show that the failure mode of the waste dump slope is two wedges if the weak layer is located on the ground surface (Model A), while the slope can be observed as three wedges failure if the weak layer is below the ground surface (Model B). In addition, both failure modes are highly sensitive to the friction angle of the weak layer and the shear strength of waste disposal, and moderately sensitive to the heap height, the dip angle and cohesion of the weak layer, while the toe cutting has limited effect on the slope stability. Moreover, the sensitivity to the excavation of the ground depends on the location of the weak layer and failure mode.

• The Journal of Engineering Geology
• /
• v.18 no.4
• /
• pp.405-414
• /
• 2008

When we evaluate slope stability, we regard the slope homogeneous and evaluate slope stability at the most dangerous portion of slope. However, since conditions and properties of rock mass/soil are different from one location to another within a single slope, slope stability evaluated by current concept can not represent slope correctly. This also result in over-reinforcement at the portion where reinforcement is not necessary. In order to solve these problems, we suggest a cell unit evaluation method in which we apply small rectangular cells in a slope and regard each cell as a single slope. In this method, slopes are classified into soil slope and rock slope depending on materials. Strength of rock, volumetric joint count, spacing of joints, condition of joints, ground water condition and so on are examined and SMR and condition index values are calculated. Finally, all data and results are presented as contour maps. We apply the cell unit evaluation method into 3 cut slopes. SMR values estimated by the new method are larger than those by current concept at most portions of slope, indicating that the new method suggested by this research represent slope stability more correctly than methods which were used. This method will prevent over-reinforcement at the portion of slope where reinforcement is not necessary.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.475-480
• /
• 2003

Traditionally, the statistical methods analyze the relationship between landslide occurrence and related factors(soil depth, soil strength, slope angle, vegetation, etc.) in GIS technique. However, those methods have no mechanical meaning. Therefore, the deterministic model is suggested in this research. The method analyzes the mechanical equilibrium of a potential slide block and then calculates a slope safety factor. Since this method is able to consider the balance of forces applied to the slope and is a more reasonable method for an individual site. In this research, the spatial data is obtained, managed and analyzed using GIS technique. The infinite slope model is used to evaluate factor of safety and analyze the slope stability.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.681-686
• /
• 2006

This study is to examine slope activity safety ratio on the strength of the natural sample or soil collected through field test in the slope activity region during destruction happened in the course of soil-relocating work planned for ground improvement under strict supervision at the house-building site, using Bishop's slope analysis method and investigate relationship between slope analysis theories and actual destruction so as to compare determining method of clean water of soil essential for slope activity analysis and accuracy of resulting value of clean water of soil.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.930-937
• /
• 2008

From the result of precise field investigation and stability analysis for the cut slope, following results were acquired. 1. The cause of the collapse of cut slope came from circle sliding collapse by fault zone which remained inner weathering zone. 2. The existing destructed soil and rock can be removed by reinforcement. And to prevent the additional destruction, it is judged that applying the method after relaxing the slope would be reasonable. 3. To make cut slope stable, soft rock layer should be done cutting 1:1.5 and 1:2.0 ~ 1:2.5 for weathered rock and soil layer. 4. Heavy water leakage section should be applied horizontal drain method so that water pressure should not act to the cut slope.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.167-174
• /
• 2000

Profiles of discontinuities through scanline method were investigated for the analysis of rock slope stability. Lower hemispheric projection method was used to evaluate the geometric stability and failure potential of these discontinuities. Also, safety factor was evaluated for the discontinuities of failure potential using by limit equilibrium analysis. Then, displacements of rock block due to the discontinuities were displayed by using the program UDEC(Universal Distinct Element Code) which applied the Distinct Element Method. When we determine the cut-slope in design, the characteristics of discontinuities is not represented only by strength parameters of intact rock. Therefore it is more reasonable method in assuring stability that first, construction would be preceded by the cut-slope of preliminary design, and then, cut-slope would be redetermined by elaborate site investigation in processing construction.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.55 no.11
• /
• pp.471-475
• /
• 2006

In this paper, we propose a method to eliminate the baseline wander for ECG based on waveform morphology analysis. This method uses the ascending slope tracing waves to approximate the baseline wander in ECG and subtracts these waves from the original ECG to eliminate the baseline wander. This ascending slope tracing waves was developed for efficient enhancement of slope inverting points and sudden slope changing points. This method has been applied to MIT/BIH database to verify its efficacy and validity in practical applications.

• The Journal of Engineering Geology
• /
• v.16 no.2 s.48
• /
• pp.189-199
• /
• 2006

This paper presents a field study of the stability of slope collapsed during road construction and proposes a reasonable countermeasure if the current slope is unstable. As a result of slope investigation, it was found that the slope includes five tension cracks and the sliding surface is started from the tension crack and propagated the surface soil layer through weathered rock layer. The slope stability analyses are conducted in case of dry and rainfall seasons. The results indicate that the slope is unstable status. A reinforcement method of slope failure should be selected according to the scale of failure. That is, the scale of slope failure, which is classified small, middle and large size determines the reinforcement method of slope. Since the slope interested in this study is large size failure slope, the reinforcement method to control slope failure is selected stabilizing piles, and seed spray and drainage of surface waterare also selected to remain the factor of safety. The SLOPILE (Ver. 3.0) program is applied in order to do stability analysis of slope reinforced by piles. As the result of analysis, the slope reinforced by a row of piles shows the stable state. It is clearly confirmed that the stabilizing of piles can improve the stability of slope.

• Geomechanics and Engineering
• /
• v.22 no.3
• /
• pp.207-217
• /
• 2020

Slope reliability analysis and risk assessment for spatially variable soils under rainfall infiltration are important subjects but they have not been well addressed. This lack of study may in part be due to the multiple and diverse evaluation indexes and the low computational efficiency of Monte-Carlo simulations. To remedy this, this paper proposes a highly efficient computational method for investigating random field problems for slopes. First, the probability density evolution method (PDEM) is introduced. This method has high computational efficiency and does not need the tens of thousands of numerical simulation samples required by other methods. Second, the influence of rainfall on slope reliability is investigated, where the reliability is calculated from based on the safety factor curves during the rainfall. Finally, the uncertainty of the sliding mass for the slope random field problem is analyzed. Slope failure consequences are considered to be directly correlated with the sliding mass. Calculations showed that the mass that slides is smaller than the potential sliding mass (shallow surface sliding in rainfall). Sliding mass-based risk assessment is both needed and feasible for engineered slope design. The efficient PDEM is recommended for problems requiring lengthy calculations such as random field problems coupled with rainfall infiltration.

• Journal of Industrial Technology
• /
• v.33 no.A
• /
• pp.73-80
• /
• 2013

This paper is results of numerical analysis on the behavior of colluvium slope with combinations of soil nails and earth anchors during excavation. In order to maintain the stability of the colluvium cut, being composed of gravel and boulder and thus local in stability being expected during slope cut, temporary reinforcing method of soil nailing with shotcrete might be used. Subsequent method of cast-in-place facing with earth anchors can be used to maintain cut slope stable permanently. For the cut slope where these methods had been applied, the numerical techniques were applied to their behaviors and investigate the stability of the slope. Limit equilibrium methods were used to confirm to maintain the slope stability during and after excavation and application of those reinforcing methods. Another numerical technique of FEM was also used to find the stress and strain as well as deformation distribution in reinforcing materials and slope ground during excavation.