Limit equilibrium method with local factors of safety for slope stability

1987 ◽  
Vol 24 (4) ◽  
pp. 652-656 ◽  
Author(s):  
Milutin M. Srbulov
Keyword(s):  
Slope Stability ◽  
Limit Equilibrium ◽  
Soil Mass ◽  
Local Factors ◽  
A Value ◽  
Equilibrium Approach ◽  
Current Design ◽  
Soil Strain ◽  
The Stability ◽  
Definition Of

Current design practice often involves the consideration of slope stability when the strength parameters of the soil or the pore pressures vary considerably within a slope. In these cases it is evident that, because of departures from homogeneity, the soil mass may slip along a noncircular surface and local overstress will occur if the factor of safety lies below a value of about 1.8. Overstress also occurs when a slope contains materials that activate their shear resistances under significantly different stress – strain relationships. Therefore, the objective of this paper is to describe a new limit equilibrium approach suitable for the consideration of the heterogeneous slopes. A new definition of local factors of safety distribution, not only along a trial sliding surface but also at the interfaces of wedge-shaped slices, is introduced considering the soil strain properties. The main features of the comptutational procedure are outlined. One illustrative example dealing with the stability of a heterogeneous slope is included. Key words: limit equilibrium, slope stability, local factors of safety.

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.

Some difficulties associated with the limit equilibrium method of slices

1983 ◽  
Vol 20 (4) ◽  
pp. 661-672 ◽  
Author(s):  
R. K. H. Ching ◽  
D. G. Fredlund
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Stability Limit ◽  
Limit Equilibrium Method ◽  
Soil Conditions ◽  
Side Force ◽  
Limit Equilibrium Methods ◽  
Equilibrium Method ◽  
The Stability

Several commonly encountered problems associated with the limit equilibrium methods of slices are discussed. These problems are primarily related to the assumptions used to render the inherently indeterminate analysis determinate. When these problems occur in the stability computations, unreasonable solutions are often obtained. It appears that problems occur mainly in situations where the assumption to render the analysis determinate seriously departs from realistic soil conditions. These problems should not, in general, discourage the use of the method of slices. Example problems are presented to illustrate these difficulties and suggestions are proposed to resolve these problems. Keywords: slope stability, limit equilibrium, method of slices, factor of safety, side force function.

Study on Evaluation of High Slope Stability and Countermeasures Based on GEO-SLOPE

2014 ◽  
Vol 988 ◽  
pp. 371-376
Author(s):  
Nian Qin Wang ◽  
Qing Tao Wang ◽  
Qi Pang ◽  
Qian Xue
Keyword(s):  
Slope Stability ◽  
Limit Equilibrium ◽  
Optimization Analysis ◽  
High Slope ◽  
Stability Coefficient ◽  
Anchor Cable ◽  
Before And After ◽  
The Stability ◽  
Reinforcement Measures

Based on the theory of limit equilibrium, by the GEO-SLOPE software,analyzed the stability before and after reinforcement of a high Loess-bedrock slope. The results and conclusions show: (1)Analyzed and Optimized the high Loess-bedrock slope through SLOPE/W module, optimizing the engineering quantity of the anchor cable frame in the local and saving the investment; (2)When taken reinforcement measures, conducted the SLOPE/W model again, the stability coefficient is 1.459, the effect testified by projects is obvious; (3)Aiming at the optimization analysis, proposed countermeasures system, with reference for reinforcement of a high Loess-bedrock slope.

Analyses for the stability of potash tailings piles

1993 ◽  
Vol 30 (3) ◽  
pp. 491-505 ◽  
Author(s):  
Delwyn G. Fredlund ◽  
Zai Ming Zhang ◽  
Karen Macdonald
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Field Studies ◽  
Equilibrium Analysis ◽  
Limit Equilibrium Analysis ◽  
Dissipation Model ◽  
The Stability

The stability of potash tailings piles is investigated using a pore-water pressure generation and dissipation model together with a limit equilibrium analysis. It is found that a shallow toe failure mode is generally the most applicable and that the stability may be influenced by pore-water pressure migration below the pile. It is suggested that field studies would be useful in evaluating stability in the toe region of the pile. Key words : potash tailings, slope stability, pore pressure dissipation, solutioning.

Search of the Most Dangerous in Slide Slope Stability Analysis Based on Genetic Algorithm

2012 ◽  
Vol 166-169 ◽  
pp. 2535-2538
Author(s):  
Ke Wang ◽  
Chang Ming Wang ◽  
Fang Qi ◽  
Cen Cen Niu
Keyword(s):  
Genetic Algorithm ◽  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Evolutionary Process ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Equilibrium Method ◽  
The Stability

The traditional limit equilibrium method in the analysis of slope stability not only exists some subjective empirical hypothesis that can not meet the equilibrium of force and moment, but also ignores the effects of internal stress and strain on the slope stability. Furthermore, in the stability of the slope evaluation, limit equilibrium method relies too much on experience when hypothesizing the slope slip surface. So that it makes deviation on slope analysis and stability evaluation. This paper is based on simplified Bishop method used to establish the model of slope stability analysis. And it used genetic algorithms to solve the minimum safety factor and the most dangerous slip surface of slope. It was the arithmetic which simulates organisms genetic evolutionary process and it avoided the traditional methods falling into the local extreme value point easily and error propagation leading to convergence. The algorithm had advantages of higher accuracy, quick convergence and applicability. It showed that the genetic algorithm is accurate and reliable in the analysis of slope stability.

scholarly journals Brasília municipal solid waste landfill: a case study on flow and slope stability

2021 ◽  
Vol 44 (3) ◽  
pp. 1-13
Author(s):  
José Fernando Jucá ◽  
Alison Norberto ◽  
José Ivan Santos Júnior ◽  
Fernando Marinho
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Limit Equilibrium ◽  
Drainage System ◽  
Equilibrium Analysis ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Cause Of Failure ◽  
Leachate Level ◽  
The Stability

For geotechnical and environmental reasons, landfills are positioned above the regional water table and thus are formed in unsaturated conditions. This condition can be different if the drainage system and the rain regime of the site are such that they create a level of internal liquid in the landfill. During January and February 2019, excessive movements occurred in the slopes of the Brasília sanitary landfill. A geotechnical investigation indicated that the raised leachate level caused by the clogging of the drainage system contributed to the landfilled waste movements. The limit equilibrium analysis was used to predict the relationship between leachate level and slope stability. In order to understand the process that led to the rupture, flow and stability analysis by limit equilibrium were performed. The parameters associated with flow, water retention capacity, and shear strength were obtained based on literature evaluations. In addition, data from tests were used, which allowed to define more accurately the distribution of pore pressures of liquid that led to the failure. This study allowed to define the cause of failure and also to establish the role of the drainage system in maintaining the stability of the landfill. The studies indicated that although the gain of shear strength of landfill due to the unsaturated condition is negligible, the process of flow in unsaturated medium, associated with climatic aspects, are fundamental for a medium- and long-term analysis.

scholarly journals AN EVALUATION OF ROCK SLOPE STABILITY USING LIMIT EQUILIBRIUM ANALYSES

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Faridha Aprilia ◽  
I Gde Budi Indrawan
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Plane Failure ◽  
General Limit ◽  
The Stability ◽  
Equilibrium Analyses ◽  
Limit Equilibrium Analyses

The stability of rock slopes is controlled by several factors, such as the intact rock strength, discontinuity characteristics, groundwater condition, and slope geometry. Limit equilibrium (LE) analyses have been commonly used in geotechnical practice to evaluate the stability of rock slopes. A number of methods of LE analyses, ranging from simple to sophisticated methods, have been developed. This paper presents stability analyses of rock slopes at the Batu Hijau open mine in Sumbawa Barat using various methods of LE analyses. The LE analyses were conducted at three cross sections of the northern wall of the open mine using the Bishop Simplified, Janbu Simplified, Janbu Generalised, and General Limit Equilibrium (GLE) methods in Slide slope stability package. In addition, a Plane Failure (PF) analysis was performed manually. Shear strength data of the discontinuity planes used in the LE analyses were obtained from back analyses of previous rock slope failures. The LE analysis results showed that the rock slopes were likely to have shallow non-circular critical failure surfaces. The factor of safety (Fs) values obtained from the Bishop Simplified, Janbu Simplified, Janbu Generalised, and GLE methods were found to be similar, while the Fs values obtained from the PF method were higher than those obtained from the more rigorous methods. Keywords: Batu Hijau mine, Bishop Simplified, Janbu Simplified, Janbu Generalised, limit equilibrium analyses, general limit equilibrium, rock slope stability, plane failure.

Comparing slope stability analysis using limit equilibrium and finite elements simulations of deep-seated landslides along the western margin of the Main Ethiopian Rift

2021 ◽  
Author(s):  
Tesfay Kiros Mebrahtu ◽  
Thomas Heinze ◽  
Stefan Wohnlich
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Strength Reduction ◽  
Ethiopian Rift ◽  
Seismic Load ◽  
Main Ethiopian Rift ◽  
Western Margin ◽  
The Stability

<p>Landslides and ground failures are among the common geo-environmental hazards in many of the tectonically active hilly and mountainous terrains of Ethiopia, such as in the western margin of the Main Ethiopian Rift in Debre Sina area. Besides the geological preconditioning, bi-modal monsoon and seismic events in the tectonically highly active region are usually suspected triggers. In order to minimize the damage caused by the slope failure events, a detailed investigation of landslide-prone areas using numerical modelling plays a crucial role. The aim of this study is to assess the stability of slopes, to understand the relevant failure mechanisms, and to evaluate and compare safety factors calculated by the different available numerical methods. The stability was assessed for slopes of complex geometry and heterogeneous material using the limit equilibrium method and the shear strength reduction method based on finite elements. Furthermore, numerical analysis was done under static and pseudo-static loading using the horizontal seismic coefficient to model their stability during a seismic event. The slope stability analysis indicates that the studied slopes are unstable, and any small scale disturbance will further reduce the factor of safety and probably causing failure. The critical strength reduction factors from the finite element method are significantly lower than the factor of safety from the limit equilibrium method in all studied scenarios, such as Bishop, Janbu Simplified, Spencer and Morgenstern-Price. The difference is especially evident for heterogeneous slopes with joints, which often are initiation points for the failure planes. The simulations show that slope stability of landslide prone hills in the study area strongly depends on the saturation conditions and the seismic load. The studied slopes are initially close to failure and increased pore-pressure or seismic load are very likely triggers.</p>

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