Determination of three-dimensional shape of failure in soil slopes

2015 ◽  
Vol 52 (9) ◽  
pp. 1283-1301 ◽  
Author(s):  
Roohollah Kalatehjari ◽  
Ali Arefnia ◽  
Ahmad Safuan A Rashid ◽  
Nazri Ali ◽  
Mohsen Hajihassani
Keyword(s):  
Slope Stability ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Failure Surface ◽  
Small Scale ◽  
3D Shape ◽  
Finite Element Software ◽  
Soil Slopes ◽  
3D Slope Stability

This paper presents the application of particle swarm optimization (PSO) in three-dimensional (3D) slope stability analysis to determine the shape and direction of failure as the critical slip surface. A detailed description of adopted PSO is presented and a rotating ellipsoidal shape is introduced as the possible failure surface in the analysis. Based on the limit equilibrium method, an equation of factor of safety (FoS) was developed with the ability to calculate the direction of sliding (DoS) in its internal process. A computer code was developed in Matlab to determine the 3D shape of the failure surface and calculate its FoS and DoS. Then, two example problems were used to verify the applicability of the presented code, the first by conducting a comparison between the results of the code and PLAXIS-3D finite element software and the second by re-analyzing an example from the literature to find the 3D failure surface. In addition, a hypothetical 3D asymmetric slope was introduced and analyzed to demonstrate the ability of the presented method to determine the shape and DOS of failure in 3D slope stability problems. Finally, a small-scale physical model of a 3D slope under vertical load was constructed and tested in the laboratory and the results were re-analyzed and compared with the code results. The results demonstrate the efficiency and effectiveness of the presented code in determining the 3D shape of the failure surface in soil slopes.

scholarly journals The Contribution of Particle Swarm Optimization to Three-Dimensional Slope Stability Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Roohollah Kalatehjari ◽  
Ahmad Safuan A Rashid ◽  
Nazri Ali ◽  
Mohsen Hajihassani
Keyword(s):  
Particle Swarm Optimization ◽  
Stability Analysis ◽  
Slope Stability ◽  
Three Dimensional ◽  
Particle Swarm ◽  
Slope Stability Analysis ◽  
Swarm Optimization ◽  
Finite Element Software ◽  
Soil Slopes ◽  
3D Slope Stability

Over the last few years, particle swarm optimization (PSO) has been extensively applied in various geotechnical engineering including slope stability analysis. However, this contribution was limited to two-dimensional (2D) slope stability analysis. This paper applied PSO in three-dimensional (3D) slope stability problem to determine the critical slip surface (CSS) of soil slopes. A detailed description of adopted PSO was presented to provide a good basis for more contribution of this technique to the field of 3D slope stability problems. A general rotating ellipsoid shape was introduced as the specific particle for 3D slope stability analysis. A detailed sensitivity analysis was designed and performed to find the optimum values of parameters of PSO. Example problems were used to evaluate the applicability of PSO in determining the CSS of 3D slopes. The first example presented a comparison between the results of PSO and PLAXI-3D finite element software and the second example compared the ability of PSO to determine the CSS of 3D slopes with other optimization methods from the literature. The results demonstrated the efficiency and effectiveness of PSO in determining the CSS of 3D soil slopes.

A Comparative Study on Locating Critical Slip Surface in 2D and 3D Limit Equilibrium Stability Analysis of Slopes

2012 ◽  
Vol 446-449 ◽  
pp. 1905-1913
Author(s):  
Mo Wen Xie ◽  
Zeng Fu Wang ◽  
Xiang Yu Liu ◽  
Ning Jia
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Slope Stability Analysis ◽  
Equilibrium Stability ◽  
Critical Slip Surface ◽  
Minimum Safety Factor

The Various methods of optimization or random search have been developed for locating the critical slip surface of a slope and the related minimum safety factor in the limit equilibrium stability analysis of slope. But all these methods are based on a two-dimensional (2D) method and no one had been adapted for a search of the three-dimensional (3D) critical slip surface. In this paper, a new Monte Carlo random simulating method has been proposed to identify the 3D critical slip surface, in which assuming the initial slip to be the lower part of an ellipsoid, the 3D critical slip surface in the 3D slope stability analysis is located by minimizing the 3D safety factor of limit equilibrium approach. Based on the column-based three-dimensional limit equilibrium slope stability analysis models, new Geographic Information Systems (GIS) grid-based 3D deterministic limit equilibrium models are developed to calculate the 3D safety factors. Several practical examples, of obtained minimum safety factor and its critical slip surface by a 2D optimization or random technique, are extended to 3D slope problems to locate the 3D critical slip surface and to compare with the 2D results. The results shows that, comparing with the 2D results, the resulting 3D critical slip surface has no apparent difference only from a cross section, but the associated 3D safety factor is definitely higher.

scholarly journals Three Dimensional Slope Stability Analysis of Open Pit Mine

2020 ◽  
Author(s):  
Masagus Ahmad Azizi ◽  
Irfan Marwanza ◽  
Muhammad Kemal Ghifari ◽  
Afiat Anugrahadi
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Slope Stability Analysis ◽  
Open Pit ◽  
3 Dimensional ◽  
Grid Points ◽  
Convergence Type

The 3-dimensional slope stability analysis has been developing rapidly since the last decade, and currently a number of geomechanical researchers in the world have put forward ideas for optimization of slope design related to the economics and safety of mining operations. The 3-dimensional slope stability analysis methods has answered the assumption of spatial parameters in determining safety factors and the failure probability, thus the volume of failed material and the location of the most critical slopes can be determined. This chapter discusses two methods of 3-dimensional slope stability analysis, namely the limit equilibrium method (LEM) and finite element method (FEM). LEM 3D requires an assumption of failure type with the variable of analysis are the maximum number of columns, the amount of grid points, increment radius, and type of slip surface. On the other hand, FEM 3D requires an assumption of convergence type, absolute force and energy, with the variable of analysis are mesh type and maximum number of iterations. LEM 3D shows that the cuckoo algorithm is reliable in obtaining position and shape of slip surface. Meanwhile FEM 3D, the optimum iteration number needs to be considered to improve analysis efficiency and preserving accuracy.

Three-dimensional slope stability study using a Coupled Eulerian-Lagrangian method

2020 ◽  
Author(s):  
Fang-Cing Liu ◽  
Chih-Hsuan Liu ◽  
Ching Hung
Keyword(s):  
Finite Element ◽  
Stability Analysis ◽  
Slope Stability ◽  
Complex Geometry ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Slope Stability Analysis ◽  
Stability Study ◽  
Element Analysis ◽  
3D Slope Stability

<p>  In slope stability analysis, two-dimensional (2D) analysis techniques are usually applied due to its simplicity and extensive applicability. Given that slope failures are three-dimensional (3D) in nature, especially in the slope with complex geometry, a 3D slope stability analysis could lead to more reasonable results [1]. In slope stability analyses, limit equilibrium method (LEM) and finite element method (FEM) are widely used. Note that LEM only satisfies equations of statics and does not consider strain and displacement compatibility; FEM may encounter significant mesh distortion during large deformations where convergence difficulty and the analysis may be terminated before the slope reaches failure [2]. In the study, a Coupled Eulerian-Lagrangian (CEL) method, which allows materials to flow through fixed meshes regardless of distortions, was utilized to investigate 3D slope stability [3]. Validation of the numerical modeling was first presented using a typically assumed 3D slope. After the validation, various types of slopes (i.e. turning corners, convex- and concave-shaped surfaces) with various boundary conditions (unrestrained, semi-restrained, and fully restrained) are carefully conducted to examine the 3D slope stability. It is anticipated the 3D analyses can shed some light on the slope stability analysis with extreme or complex geometry cases and provide more reasonable results.</p><p> </p><p>REFERENCE</p><ol><li>T.-K. Nian, R.-Q. Huang, S.-S. Wan, and G.-Q. Chen (2012): Three-dimensional strength-reduction finite element analysis of slopes: geometric effects. Canadian Geotechnical Journal, 49: 574–588.</li> <li>C. Hung, C.-H. Liu, G.-W. Lin and Ben Leshchinsky (2019): The Aso-Bridge coseismic landslide: a numerical investigation of failure and runout behavior using finite and discrete element methods. Bulletin of Engineering Geology and the Environment. doi: 10.1007/s10064-018-1309-3.</li> <li>C. Han. Lin, C. Hung and T.-Y. Hsu (2020): Investigations of granular material behaviors using coupled Eulerian-Lagrangian technique: From granular collapse to fluid-structure interaction. Computers and Geotechnics (under review).</li> </ol><p> </p><p> </p>

Three-dimensional slope stability based on stresses from a stress-deformation analysis

2011 ◽  
Vol 48 (6) ◽  
pp. 891-904 ◽  
Author(s):  
J.R. Stianson ◽  
D.G. Fredlund ◽  
D. Chan
Keyword(s):  
Stress Distribution ◽  
Slope Stability ◽  
Internal Stress ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Equilibrium Analysis ◽  
Deformation Analysis ◽  
Stress Deformation ◽  
The Stability

A procedure is developed where stresses from a finite element analysis are incorporated into a limit equilibrium framework to evaluate the stability of three-dimensional slopes. An independent stress-deformation analysis is performed to calculate the internal stress state for the slope. The stress distribution is imported into the three-dimensional slope stability analysis in the form of a regular grid. The slip surfaces considered in the limit equilibrium analysis are ellipsoidal and discretized using a series of triangular planes. The normal and shear force acting at the centroid of individual triangular planes can be computed from the internal stress distribution. Subsequently, the factor of safety of a selected slip surface can be calculated directly without using an iterative procedure. A series of verification examples are presented to confirm that the proposed method provides the required accuracy and flexibility to assess the stability of slopes typically encountered in practice. Sensitivity analyses are presented to show how the procedure used to compute the forces acting on each triangular plane, the number of planes used to discretize the slip surface, and Poisson’s ratio influence the computed factors of safety, but do not limit the successful application of the methodology.

The effect of strength envelope nonlinearity on slope stability computations

2003 ◽  
Vol 40 (2) ◽  
pp. 308-325 ◽  
Author(s):  
J -C Jiang ◽  
R Baker ◽  
T Yamagami
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Failure Criterion ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Integrated Approach ◽  
Equilibrium Analysis ◽  
Experimental Database ◽  
Stress Dependent

Engineering analysis of slope stability includes three separate but interrelated phases: (a) experimental strength measurements, (b) determination of a strength envelope that best fits the experimental results, and (c) formal limiting equilibrium analysis using the resulting strength envelopes. Studying the interrelations between these phases leads to an integrated approach to slope stability analysis. The present work uses a single experimental database that is fitted with both linear (Mohr–Coulomb) and nonlinear failure envelopes and investigates the effect of different forms of the failure criterion on slope stability computations for both 2D and 3D problems. It has been indicated that calculated minimum safety factors could be significantly overestimated by the linear approximation of a nonlinear strength envelope. The effect of neglecting strength envelope nonlinearity is more pronounced under 3D conditions than in a 2D simplification. As a result, the use of nonlinear failure criterions in slope stability analyses is recommended to account for the stress-dependent nature of the shear strength of soils.Key words: nonlinear strength envelope, Mohr–Coulomb failure criterion, limit equilibrium, critical slip surface, minimum factor of safety, three-dimensional stability analysis.

A simplified method for 3D slope stability analysis

2003 ◽  
Vol 40 (3) ◽  
pp. 675-683 ◽  
Author(s):  
Zuyu Chen ◽  
Hongliang Mi ◽  
Faming Zhang ◽  
Xiaogang Wang
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Upper Bound ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Slope Stability Analysis ◽  
Accurate Solution ◽  
The Moment ◽  
3D Slope Stability ◽  
Force Equilibrium

This paper presents a simplified three-dimensional (3D) slope stability analysis method based on the limit equilibrium theory. The assumption involved in this method is of a parallel intercolumn force inclination, similar to Spencer's method in the two-dimensional (2D) area. It allows for the satisfaction of complete overall force equilibrium conditions and the moment equilibrium requirement about the main axis of rotation. The method has been proven to be numerically tractable for many practical problems. By combining this method with the 3D upper bound approaches, it is possible to bracket the accurate solution of a 3D slope stability analysis problem into a small range.Key words: slope stability analysis, three-dimensional analysis, limit equilibrium method, upper bound method.

scholarly journals Application of cuckoo search method in 3D slope stability analysis for limestone quarry mine

2020 ◽  
Vol 23 (2) ◽  
pp. 57-65
Author(s):  
Masagus Azizi ◽  
◽  
Irfan Marwanza ◽  
Nadya Hartanti ◽  
Muhammad Ghifari ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Cuckoo Search ◽  
Slope Stability Analysis ◽  
Efficient Global Optimization ◽  
Grid Search ◽  
3D Slope Stability

The Cuckoo Search (CS) is a very fast and efficient global optimization method to locating the slip surface which carried out by iteration. However, the Grid Search (conventional method) method in 3D slope stability analysis takes longer than this method on the computation process. Slope stability analysis was performed using the 3D limit equilibrium method “Bishop” with Cuckoo Search of slip surface by maximizing iteration of the simulation and columns in X or Y. To ensure that the slip surface within the global minimum slip surface, the maximum iteration in CS was also specified from 40 to 1200. Based on maximum columns in X or Y, the safety factor value of the 3D CS results was then compared to the Grid Search results to determine the final 3D safety factor and the estimated volume of potential failure. The final 3D safety factor obtained from the average 3D safety factor (with maximum iteration 400, 800, 1000, and 1200) is about 2,01 with the average estimated volume of slope failure of 190.000 m3 that located at the north of the pit.

A 3D slope stability analysis method assuming parallel lines of intersection and differential straining of block contacts

2002 ◽  
Vol 39 (4) ◽  
pp. 799-811 ◽  
Author(s):  
Muhsiung Chang
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Block System ◽  
Stability Of Slopes ◽  
Sliding Mechanism ◽  
The Stability

A three-dimensional (3D) method of analysis of the stability of slopes was developed based on the sliding mechanism observed in the 1988 failure of the Kettleman Hills landfill slope (Kettleman City, California) and the associated model studies. By adopting a limit equilibrium concept, the method assumes the sliding mass as a block system in which the contacts between blocks are inclined. The lines of intersection of the block contacts are assumed to be parallel, which enables the sliding kinematics. In consideration of the differential straining between blocks, the shear stresses on the slip surface and the block contacts are evaluated based on the degree of shear strength mobilization on these contacts. The overall factor of safety is calculated based on the force equilibrium of the individual blocks and the entire block system as well. Based on comparisons with a series of hypothetical 3D and 2D problems with known solutions, the method was generally found to be accurate in predicting the stability of slopes involving a translational type of sliding failure. For rotational sliding failures in clays, however, the method appears to slightly overestimate the calculated factor of safety; up to as much as 10% in a typical problem examined in this study.Key words: slope stability, 3D method, limit equilibrium, block kinematics, strain incompatibility.

scholarly journals The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 73
Author(s):  
Panagiotis Sitarenios ◽  
Francesca Casini
Keyword(s):  
Analytical Solution ◽  
Slope Stability ◽  
Slope Failure ◽  
Failure Modes ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Three Dimensional ◽  
Stability Limit ◽  
Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

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