scholarly journals Stability Analysis of Anchored Soil Slope Based on Finite Element Limit Equilibrium Method

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Rui Zhang ◽  
Jie Zhao ◽  
Guixuan Wang
Keyword(s):  
Finite Element ◽  
Stability Analysis ◽  
Safety Factor ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Element Analysis ◽  
Surface Anchoring ◽  
Equilibrium Method ◽  
Slice Method

Under the condition of the plane strain, finite element limit equilibrium method is used to study some key problems of stability analysis for anchored slope. The definition of safe factor in slices method is generalized into FEM. The “true” stress field in the whole structure can be obtained by elastic-plastic finite element analysis. Then, the optimal search for the most dangerous sliding surface with Hooke-Jeeves optimized searching method is introduced. Three cases of stability analysis of natural slope, anchored slope with seepage, and excavation anchored slope are conducted. The differences in safety factor quantity, shape and location of slip surface, anchoring effect among slices method, finite element strength reduction method (SRM), and finite element limit equilibrium method are comparatively analyzed. The results show that the safety factor given by the FEM is greater and the unfavorable slip surface is deeper than that by the slice method. The finite element limit equilibrium method has high calculation accuracy, and to some extent the slice method underestimates the effect of anchor, and the effect of anchor is overrated in the SRM.

Slope Stability Analysis of Elastic Limit Equilibrium Method

2013 ◽  
Vol 275-277 ◽  
pp. 1423-1426
Author(s):  
Lin Kuang ◽  
Ai Zhong Lv ◽  
Yu Zhou
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Sliding Surface ◽  
Tangential Stresses ◽  
Equilibrium Method

Based on finite element analysis software ANSYS, slope stability analysis is carried out by Elastic limiting equilibrium method proposed in this paper. A series of sliding surface of the slope can be assumed firstly, and then stress field along the sliding surface is analyzed as the slope is in elastic state. The normal and tangential stresses along each sliding surface can be obtained, respectively. Then the safety factor for each slip surface can be calculated, the slip surface which the safety factor is smallest is the most dangerous sliding surface. This method is different from the previous limit equilibrium method. For the previous limit equilibrium method, the normal and tangential stresses along the sliding surface are calculated based on many assumptions. While, the limit equilibrium method proposed in this paper has fewer assumptions and clear physical meaning.

Landslide Stability Analysis Based on GeoStudio

2013 ◽  
Vol 634-638 ◽  
pp. 3701-3704 ◽  
Author(s):  
Rui Wang ◽  
Xi Wang ◽  
Kun Yin ◽  
Yang Zhao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stability Analysis ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
Sliding Surface ◽  
Landslide Stability ◽  
Equilibrium Method ◽  
Element Method

In order to monitor landslide risk, GeoStudio software is frequently applied to landslide stability analysis. In this paper, Juting landslide in Shanxi was subjected by GeoStudio software, while limit equilibrium method was adopted to calculate the landslide stability in the slip surface. The solutions of stress and displacement vector were gotten through SIGMA / W module on the landslide for finite element method in sliding surface stress analysis. And it was also used to import the results obtained in SIGMA / W module into SLOPE / W module to calculate safety factor and the potential sliding surface. The result shows that the calculated safety factors which are worked out by those two ways are close to each other, and limit equilibrium method can be used in landslide stability analysis, but the finite element method is more consistent with the actual situation. GeoStudio software can calculate landslide stability coefficient conveniently, and can express potential slip surface intuitively, providing reliable foundation for landslide stability analysis.

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.

Study of the Three-Dimensional Global Limit Equilibrium Method Applied to the Stability of Rock Slope

2012 ◽  
Vol 249-250 ◽  
pp. 1099-1102
Author(s):  
Yi Sheng Huang ◽  
Jian Lin Li
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Limit State ◽  
Three Dimensional ◽  
Limit Equilibrium Method ◽  
Equilibrium Method ◽  
The Stability ◽  
Loose Rock

Amending the normal stress over the slip surface based on the stress field by numerical analysis, applying the three-dimensional global limit equilibrium method to the stability analysis of tension-slackened rock mass in the right bank of Yagen hydropower station. Stability analysis shows that if do not take any measures, the loose rock mass stability can cater to the Specification demand, but some small sliders is in the limit state under the water and earthquake condition, if use the cutting slope and unloading scheme, the whole loose rock mass and the all small sliders can meet the Specification standard stability requirements.

scholarly journals Slope Stability Analysis Using Limit Equilibrium Method in Nonlinear Criterion

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hang Lin ◽  
Wenwen Zhong ◽  
Wei Xiong ◽  
Wenyu Tang
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Limit Equilibrium ◽  
Friction Angle ◽  
Limit Equilibrium Method ◽  
Slope Stability Analysis ◽  
Cohesive Strength ◽  
Equilibrium Method ◽  
Coulomb Criterion

In slope stability analysis, the limit equilibrium method is usually used to calculate the safety factor of slope based on Mohr-Coulomb criterion. However, Mohr-Coulomb criterion is restricted to the description of rock mass. To overcome its shortcomings, this paper combined Hoek-Brown criterion and limit equilibrium method and proposed an equation for calculating the safety factor of slope with limit equilibrium method in Hoek-Brown criterion through equivalent cohesive strength and the friction angle. Moreover, this paper investigates the impact of Hoek-Brown parameters on the safety factor of slope, which reveals that there is linear relation between equivalent cohesive strength and weakening factorD. However, there are nonlinear relations between equivalent cohesive strength and Geological Strength Index (GSI), the uniaxial compressive strength of intact rockσci, and the parameter of intact rockmi. There is nonlinear relation between the friction angle and all Hoek-Brown parameters. With the increase ofD, the safety factor of slopeFdecreases linearly; with the increase of GSI,Fincreases nonlinearly; whenσciis relatively small, the relation betweenFandσciis nonlinear, but whenσciis relatively large, the relation is linear; with the increase ofmi,Fdecreases first and then increases.

Estimating critical height of unsupported trenches in vadose zone

2021 ◽  
Vol 58 (1) ◽  
pp. 66-82
Author(s):  
Adin Richard ◽  
Won Taek Oh ◽  
Gregory Brennan
Keyword(s):  
Finite Element ◽  
Vadose Zone ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Earth Pressure ◽  
Limit Equilibrium Method ◽  
Critical Height ◽  
Element Analysis ◽  
Equilibrium Method

Workers are often required to enter unsupported trenches during the construction process, which may present serious risks. Trench failures can result in death or damage to adjacent properties; therefore, trenches should be excavated with extreme precaution. Critical height (i.e., maximum depth that can be excavated without failure) is the most important design consideration for ensuring the stability of unsupported trenches. Because excavation work is often done in the vadose zone, the influence of matric suction should be taken into account when estimating the critical height of an unsupported trench. In this study, an attempt was made to estimate the critical heights of unsupported trenches using three distinct approaches: (i) analytical method based on the extended Rankine earth pressure theory, (ii) finite element coupled stress – pore-water pressure analysis, and (iii) limit equilibrium method (i.e., Bishop’s simplified and Morgenstern–Price method). It was assumed that the trenches were excavated in an engineered sand (Unimin 7030) and Indian Head till, which represent cohesionless and cohesive soils, respectively, considering various practical scenarios. Geotechnical modeling software, GeoStudio (ver. 2016; SIGMA/W and SLOPE/W), was used for both finite element analysis and the limit equilibrium method.

scholarly journals Studying the effect of a variation in the main parameters on stability of homogeneous earth dams using design experiment

2017 ◽  
Vol 34 (1) ◽  
pp. 173-179
Author(s):  
Rida Lakehal ◽  
Lakhdar Djemili
Keyword(s):  
Safety Factor ◽  
Material Properties ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Probabilistic Method ◽  
Limit State ◽  
Limit Equilibrium Method ◽  
Design Experiment ◽  
Earth Dams ◽  
Equilibrium Method

Abstract Deterministic approaches such as the limit equilibrium method (LEM) especially Bishop modified method has been traditionally used to evaluate the stability of embankment dams. However, the uncertainty associated with the material properties necessitates the use of the probabilistic method to account the sensitivity of this uncertainty on the response of the deterministic approaches. In this study, the authors propose the application of design experiment, especially central composite design (CCD) to determine the effects of independent uncertain parameters on the response of stability. A second-order polynomial model with cross terms is used to create an approximating function referred to as response surface for the implicit limit state surface, for which the input data were provided by stability analyses of different heights of homogeneous earth dams (10 m, 20 m, and 30 m) with a depth ratio of DH = 1.5 and a circular slip surface using the Bishop modified limit equilibrium method. The proposed models obtained from this application represent higher prediction accuracy. The study of the effect of geotechnical parameters (material properties of embankment) on safety factor show the importance of individual factors in level of linear effect with a positive effect of c’ or φ’ and a negative effect of H, γd, γsat and significant influence of two-factors interaction, the effect of c’ highly dependent on H, β, γd and φ’. Moreover, the effect of φ’ is dependent on the values of H and β. Lastly, the optimization of safety factor with respect to the range of values of material properties was made, and two failures modes are discussed which are (φ’, c’ reduction and γd increase).

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