scholarly journals Deterministic and Probabilistic Analysis of Dasdhunga Soil Slope along Narayangarh-Mugling Road Section

2021 ◽  
Vol 6 ◽  
pp. 187-198
Author(s):  
Saurav Shrestha ◽  
Indra Prasad Acharya ◽  
Ranjan Kumar Dahal
Keyword(s):  
Limit Equilibrium ◽  
Water Pressure ◽  
Slope Angle ◽  
Friction Angle ◽  
Probability Of Failure ◽  
Soil Slope ◽  
Extrinsic Factors ◽  
Stability Of Slopes ◽  
Road Section ◽  
Truncated Normal

Instability of slopes is usually governed by a combination of intrinsic and extrinsic factors. The inherent variability of parameters make the problem probabilistic rather than a deterministic one. This research deals with evaluation of stability of slopes with the calculation of the factor of safety of Dasdhunga soil slope along Narayangarh- Mugling road section under different rainfall conditions through the use of coupled finite element and limit equilibrium method in GeoStudio and the determination of probability of failure by sliding, modeled as infinite slopes by using Monte Carlo simulation in R-Studio. Mean, standard deviation, minimum and maximum values of the parameters like- friction angle, cohesion and unit weight were computed from eight samples of the slope. The pore water pressure developed and its corresponding statistical data for different rainfall conditions were computed from FEM based SEEP/W simulation. The above parameters are assumed to follow truncated normal probability distribution function and the geometric parameters like height and slope angle are regarded as constant parameters. It was observed that the safety factors for theslopeis low in high intensity-low duration rainfalls and the probability of failure is high. The tendency to fail increases as the return period of rainfall increases and viceversa. Sensitivity analysis performed in both deterministic and probabilistic methods showed that friction angle is the most sensitive.

Pseudo-Static Analysis of Slope Considering Circular Rupture Surface

2014 ◽  
Vol 5 (2) ◽  
pp. 37-43 ◽  
Author(s):  
Sima Ghosh
Keyword(s):  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Failure Surface ◽  
Friction Angle ◽  
Equilibrium Analysis ◽  
Seismic Slope Stability ◽  
Slide Mass ◽  
Critical Circle ◽  
Seismic Forces

In this present paper, a circular failure surface passing through the toe is assumed for a homogeneous soil, and the Fellenius line is used to locate the centre of the most critical circle. Using limit equilibrium analysis under the influence of static forces such as weight of potential slide mass and surcharge along with the pseudo-static seismic forces are considered to obtain the factor of safety of the slopes. Factor of safety is found through the application of force equilibrium. The effects of variation of different parameters like slope angle (i), soil friction angle (F) and seismic acceleration coefficients both in the horizontal and vertical directions (kh and kv respectively) on the factor of safety are presented. Finally, the present results are compared to the existing solutions available in literature and found to give minimum values of factor of safety using the present approach for seismic slope stability analysis.

scholarly journals Study of the Stability of a Soil-Rock Road Cutting Slope in a Permafrost Region of Hulunbuir

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yuxia Zhao ◽  
Jun Feng ◽  
Kangqi Liu ◽  
Hongwei Xu ◽  
Liqun Wang ◽  
...  
Keyword(s):  
High Latitude ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
In Situ Monitoring ◽  
Permafrost Region ◽  
Freeze Thaw ◽  
Stability Of Slopes ◽  
Low Altitude ◽  
The Stability ◽  
Permafrost Regions

Due to the threat of global warming and the accelerated melting of glaciers and permafrost, the stability of slopes in permafrost regions has received an increasing amount of attention from scholars. However, research on the stability of soil-rock road cutting slopes in high-latitude and low-altitude permafrost regions of the Greater Khingan Mountains in the Inner Mongolia Autonomous Region has not been reported. For this reason, a study of the stability of a slope with a high ice content in section K105 + 600 to K105 + 700 of National Highway 332 is conducted. The slope is 20 m high and the slope angle is 45°, and the risk of landslides on this slope under the action of freeze-thaw erosion is very high. Because of this, field in situ monitoring, indoor freeze-thaw tests, thermal parameter tests, and ABAQUS numerical simulation models are used to study the stability of the slope. After collecting the continuous temperature, moisture, settlement, and slope deformation data, it was found that the slope was undergoing dynamic changes. The creep of shallow slopes increased with the number of freeze-thaw cycles. After approximately 150 freeze-thaw cycles, the slope safety factor was less than 1, which means that the slope had reached the limit equilibrium state. Therefore, freeze-thaw erosion greatly reduced the stability of the slope. Hence, the stability of the slope must be protected during its entire life cycle. This study provides a reference for the design and construction of road cutting slopes in the high-latitude and low-altitude permafrost regions of the Greater Khingan Mountains.

scholarly journals Reliability Analysis of Expansive Soil Slope Stability Based on the Three-Broken Line Model

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Wenwei Li ◽  
Baotian Wang ◽  
Jinyu Zuo ◽  
Bingsheng Zhou ◽  
Haixia Zhang
Keyword(s):  
Reliability Analysis ◽  
Expansive Soil ◽  
Probability Of Failure ◽  
Rigid Bodies ◽  
Soil Parameters ◽  
Soil Slope ◽  
Safety Factors ◽  
Line Model ◽  
Stability Of Slopes ◽  
Weathered Layer

Based on the characteristics of an expansive soil slope, the slip mass can be simplified to a simpler model with three-broken line rigid bodies. A solution was formulated to calculate the safety factors of the slope, and the results are similar to those based on the strength reduction method. However, similar to conventional methods to analyze the stability of slopes, the deterministic method to obtain the safety factors only calculates the safety factor using deterministic values without considering the randomness of soil parameters, which leads to unstable results. To improve the rationality of the calculated results, this paper aims to construct a reliability analysis method based on the simplified three-broken line model of a landslide. The reliability is calculated with the response surface method in a spreadsheet with efficiency and convenience. The designed program considers the changes in the strength of the shallow soil and the depth of the strongly weathered layer for different stages of the wetting-drying cycles and solves for the probability of failure of the sliding surface at the interface between the strong and weak weathered layers. Considering an expansive soil slope as an example, the reliability of the slope was analyzed based on laboratory test data and the proposed formula. The results show that multiple wetting-drying cycles significantly increase the probability of failure of an expansive soil slope and that the slope typically becomes unstable after six wetting-drying cycles. Slope cutting helps alleviate the adverse effects of wetting-drying cycles.

scholarly journals Analysis of embankment slope stability: the comparison of finite element limit analysis with limit equilibrium methods

2019 ◽  
Vol 270 ◽  
pp. 02004
Author(s):  
Kongkit Yingchaloenkitkhajorn
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Limit Analysis ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Friction Angle ◽  
Volume Element ◽  
Stability Number ◽  
Limit Equilibrium Methods ◽  
Embankment Slope

This paper presented the analysis of embankment slope stability by considering the problem of embankment slope stability with special effects that it was filled with sand and was placed on purely cohesive clay. The finite element limit analysis of two-dimensional plane strain was employed to analyze the stability of this problem. The embankment slope height (H), the depth factors (d/H) and the embankment slope angle (β) for the finite element limit analysis of sand was modeled as a volume element with the properties of Mohr-Coulomb material in drained condition. And the clay was modeled as a volume element with the properties of Tresca material in undrained condition where the parameters were soil unit weight (γ), undrained shear strength (su) and friction angle (φ′). Parametric studies consisted of three dimensionless variables including depth factors (d/H), friction angle (φ′) and embankment slope angle (β). Results were summarized in the form of the dimensionless stability number (su/γH(FS)) and the design chart and application were presented. In addition, the comparison of the solution of stability number with the limit equilibrium methods and the failure mechanisms were also proposed in this paper.

Rock slope stability and distributed joint systems

1992 ◽  
Vol 29 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Bruce J. Carter ◽  
Emery Z. Lajtai
Keyword(s):  
Factor Of Safety ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Probability Of Failure ◽  
Cumulative Distribution ◽  
Rock Slope Stability ◽  
Sensitivity Analyses ◽  
The Stability ◽  
Rock Wedge

A deterministic (GEOSLIDE) and a probabilistic (PROSLIDE) microcomputer code are introduced to aid in performing rock wedge analyses based on the limit equilibrium method. The deterministic code evaluates the stability of a single rock wedge formed by discontinuities in rock through three-dimensional vector algebra, GEOSLIDE undertakes a full kinematic analysis (daylighting and obstruction), analyzes both wedge and plane sliding, and provides for anchor designs and sensitivity analyses (cohesion, friction, and water forces). Through multiple stability analyses, PROSLIDE evaluates the probability of failure for a rock slope by examining the distribution of the factors of safety from all the potential sliding wedges formed by the discontinuities of the rock mass. The probability of failure is expressed as the ratio of kinematically free wedges that have a factor of safety less than unity to the total number of wedges, PROSLIDE can form and analyze as many as 2000 different pairs of discontinuities in less than 30 min using a 25 MHz 486 IBM-compatible computer. In a worked example, the probability of failure for a fixed slope strike and loading condition is shown to vary with the slope angle, following the characteristic 'S' shape of a cumulative distribution function. The effect of an anchor force is to spread the distribution over a wider range of the factor of safety (SF), pushing many wedges into a potential upslide situation and splitting the distribution about the failure zone of the stability diagram (−1 < SF < 1). Key words : rock slope, rock wedge, stability analysis, factor of safety, probability of failure, Monte Carlo simulation.

The Effect of Rainfall Infiltration Time to the Unsaturated Soil Slope Stability

2011 ◽  
Vol 71-78 ◽  
pp. 4864-4867
Author(s):  
Guang Hua Cai ◽  
Hai Jun Lu ◽  
Wei He ◽  
Long Guan ◽  
Wei Qi Xu
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Rainfall Infiltration ◽  
Soil Slope ◽  
Soil Permeability ◽  
Rainfall Condition ◽  
Pressure Changes

Rainfall infiltration is currently one of the important factors in studying the soil-slope stability. By using saturated-unsaturated seepage theory, the traditional limit equilibrium method and so on, analyze the water content and the pore-water pressure changes under the rainfall condition, then analyze the influence mechanism of the slope stability. Through the Seep/W and the Slope/W of the GEO-Slope software, do the numerical simulation of the slope stability under the rainfall condition, to seek the distribution of pore-water pressure on the rainfall situation and the influence of the seepage field from various parameters such as rainfall intensity and the soil permeability coefficient, thus to study the slope stability.

scholarly journals Slope Stability Evaluation of Geosynthetic Reinforced Soil

2019 ◽  
Vol 8 (4) ◽  
pp. 7143-7147
Keyword(s):  
Slope Stability ◽  
Slope Failure ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Friction Angle ◽  
Calculation Model ◽  
Reinforced Soil ◽  
Unit Weight ◽  
Soil Parameters

The slippery of natural slope is sometimes ruled by combination of soil parameters and earthquake characteristics. Geotextiles could be a reinforcing materials and an application in numerous areas still as in geotechnical application to supply additional lateral restraint and forestall the high rise hill from failure. The analysis was aimed to analyze slope stability analysis, strengthened the Finite slope with non-woven geotextiles. The modal of hill was created within the SLOPE/W software system of GeoStudio that is predicated on limit equilibrium of slope analysis. The results of issue of safety square measure compared while not and with use of geotextiles in several layers. The issue of safety of slope failure will increase from three.437M to 9.978M victimization 3 layers of geotextiles at optimum height. Thus, this study confirms that the non-woven geotextiles may be applied in slope so as to enhance the soundness of natural or mam-made slope. During this regard, special stress is given to the sensitivity of the Calculation model input parameters like friction angle, cohesion, Pore water pressure and unit weight of soil that ought to contribute to raising awareness regarding these problems, as a requirement to create the proper selections and optimum technical resolution during this space.

scholarly journals A limit equilibrium analysis of progressive failure in the stability of slopes

1978 ◽  
Vol 15 (1) ◽  
pp. 113-122 ◽  
Author(s):  
K. Tim Law ◽  
Peter Lumb
Keyword(s):  
Slip Surface ◽  
Progressive Failure ◽  
Limit Equilibrium ◽  
Friction Angle ◽  
Soil Mass ◽  
Local Failure ◽  
Equilibrium Analysis ◽  
Stability Of Slopes ◽  
The Stability ◽  
Definition Of

A limit equilibrium method of analysis is proposed for the study of progressive failure in slope stability under a long-term condition. Based on effective stresses, the formulation of the method is derived from consideration of force and moment equilibrium within the soil mass above a prospective slip surface. By dividing the soil mass into a number of vertical slices, recognition of local failure can be made. Once local failure takes place, post-peak strength is assumed to be operative. This then initiates a redistribution of interslice forces and leads to some further local failure. Thus realistic available strengths along the slip surface can be evaluated. This permits the definition of a final safety factor, which is expressed in terms of the actual available reserve of strength. The proposed method has been applied to three well documented case records and encouraging results have been obtained. Based on the assumption that post-peak strengths are given by a friction angle equal to the peak value and a zero cohesion, stability charts have been prepared for design purposes.

scholarly journals Sensitivity Analysis on Stability Parameters in Landfill

2015 ◽  
Vol 9 (1) ◽  
pp. 108-111 ◽  
Author(s):  
Sun Hong-Jun ◽  
Fan Yan-Chao ◽  
Zhao Li-Hong
Keyword(s):  
Safety Factor ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Friction Angle ◽  
Equilibrium Analysis ◽  
Stability Parameters ◽  
Limit Equilibrium Analysis ◽  
Sensitivity Curves ◽  
Overall Stability ◽  
The Stability

To study the stability of waste body failure in landfill, the landfill was divided into two parts: an active wedge and a passive wedge. A limit equilibrium analysis was used to calculate the safety factor of stability in landfill. The parameters which affected the stability of the landfill were discussed. Sensitivity curves of each parameter were proposed and effect trends of various parameters on safety factor were analyzed. Cohesion c and internal friction angle фs increases linearly with the safety factor. The safety factor decreases with increasing slope angle β and filled height H. The safety factor of after landfill settlement was higher than the safety factor of settlement which did not occur. It increases the overall stability about 16%.

scholarly journals Slope Stability Analysis to Correlate Shear Strength with Slope Angle and Shear Stress by Considering Saturated and Unsaturated Seismic Conditions

2021 ◽  
Vol 11 (10) ◽  
pp. 4568
Author(s):  
Muhammad Israr Khan ◽  
Shuhong Wang
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Stability Analysis ◽  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Slope Stability Analysis ◽  
Soil Slope

Assessment and analysis of soil slope stability is an important part of geotechnical engineering at all times. This paper examines the assessment of soil slope stability in fine-grained soils. The effect of change in shear strength (τ), shear stress (σ) and slope angle (β) on the factor of safety has been studied. It correlates shear strength with slope angle and shear stress by considering the horizontal seismic coefficients in both saturated and unsaturated conditions. The slope failure surface was considered a circular slip surface. Statistical package for social sciences (SPSS) and Slide, numerical modeling software and limit equilibrium slope stability analysis software, respectively, are used to find out the correlations between the three basic parameters. The slope angle varied from 70 to 88 degrees, which are the most critical values for slope angles, and a total of 200 analyses were performed. τ, β and σ are correlated, and the correlations are provided in the results section. The results indicate that the correlations developed between the parameters have a very close relationship. The applicability of the developed equations is above 99%. These correlations are applicable in any type of soil slope stability analysis, where the value of shear strength and factor of safety is required with the variation of slope angle and shear stress.

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