scholarly journals A rigorous method for three-dimensional asymmetrical slope stability analysis

2018 ◽  
Vol 55 (4) ◽  
pp. 495-513 ◽  
Author(s):  
Qinghui Jiang ◽  
Chuangbing Zhou
Keyword(s):  
Slope Stability ◽  
Slip Surface ◽  
Three Dimensional ◽  
Equilibrium Equations ◽  
Equilibrium Conditions ◽  
Fast Convergence Rate ◽  
Potential Failure ◽  
Global Equilibrium ◽  
Solution Accuracy ◽  
Rigorous Method

Most slope failures exhibit remarkable asymmetrical variation in the transverse direction. A rigorous method satisfying all six equilibrium conditions is proposed for evaluating three-dimensional (3-D) asymmetrical slope stability. As there is no need to predefine a symmetrical plane in this analysis, the method is applicable to slopes with complex geometries, geologies, and loading conditions. The proposed method can not only calculate the factor of safety, but also predict the direction of sliding of the potential failure mass. Global equilibrium equations are formulated in light of the safety factor, sliding direction, and an assumed distribution of normal stress on the slip surface. The Newton method is then used to solve these equations, which has been proven to enjoy both a large range of convergence and a fast convergence rate. Thereafter, physical admissibility conditions of the solutions, and the effects of the size of discretized columns on solution accuracy, are discussed in the present 3-D analysis. The method is validated by using five typical examples documented in the literature. The failure of the Kettleman, California, waste landfill slope is also re-evaluated using the proposed method. The calculated stability and direction of sliding match field observations.

The Critical Slip Surface Search of Non-Homogeneous Slopes Based on the Global Procedure for Slope Stability Analysis

2013 ◽  
Vol 444-445 ◽  
pp. 1056-1061
Author(s):  
Cong Sun ◽  
Chun Guang Li ◽  
Hong Zheng
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Global Analysis ◽  
Analysis Method ◽  
Critical Slip Surface ◽  
Equilibrium Equations ◽  
Gradient Based ◽  
Global Equilibrium ◽  
Optimum Model

On the basis of the global analysis method of slope stability, a nonlinear optimum model is proposed for the location of the critical slip surface. In this method, both the factor of safety and vertical coordinates of discrete points on the slip surface are taken as independent variables, and the factor of safety as the objective function, with the constraints including the global equilibrium equations and convexity on the critical slip surface. For non-homogeneous slopes, a smoothing scheme is proposed. Thus the optimization problem can be solved by the classic gradient-based algorithms. The examples show that the proposed method enjoys excellent numerical stability.

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.

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 Numerical Simulation Analysis of Slope Instability and Failure of Limestone Mine in Weibei

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Kuiming Liu ◽  
Hui Li ◽  
Shihui Pang ◽  
Meng Mi ◽  
Jianping Chen ◽  
...  
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Simulation Analysis ◽  
Slip Surface ◽  
Three Dimensional ◽  
Stable State ◽  
Vertical Displacement ◽  
Slope Instability ◽  
Shaanxi Province ◽  
Geological Disaster

Weibei area is the largest limestone resource area in Shaanxi Province, which is an important boundary to distinguish the climate difference between the south and the north of China, and also a significant ecological safety protection barrier in the northwest of China. The complex geological environment and harsh environment make the mining area have serious geological disaster hidden danger. Based on the site engineering geological data of typical limestone quarry slope in Weibei, this paper constructs a three-dimensional geological model, uses FLAC3D software to simulate excavation, and analyzes the stress and strain law of the quarry slope. SlopeLE software was used to analyze the safety factor of slope stability and the potential slip surface before and after taking reinforcement measures. The results show the following: (1) Limestone is the main rock component of the mine, followed by mudstone. The joint and fissure are developed, the rock mass is broken, and the hidden danger of engineering geological disaster is high. (2) There is a sliding trend in both sides during excavation, and the maximum vertical displacement is 2.1 cm. (3) If the slope is reinforced according to the design scheme, the slope stability safety factor will be increased from 1.062 to 1.203 in a stable state, which greatly improves the stability of the slope and provides a guarantee for human and financial resources.

Three-dimensional strength-reduction finite element analysis of slopes: geometric effects

2012 ◽  
Vol 49 (5) ◽  
pp. 574-588 ◽  
Author(s):  
T.-K. Nian ◽  
R.-Q. Huang ◽  
S.-S. Wan ◽  
G.-Q. Chen
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Slip Surface ◽  
Boundary Effect ◽  
Three Dimensional ◽  
Strength Reduction ◽  
Infinite Length ◽  
Surface Geometry ◽  
Element Analysis ◽  
The Stability

The vast majority of slopes, both natural and constructed, exhibit a complex geometric configuration and three-dimensional (3D) state, whereas slopes satisfying the assumption of plane strain (infinite length) are seldom encountered. Existing research mainly emphasizes the 3D dimensions and boundary effect in slope stability analysis; however, the effect of complex geometric ground configuration on 3D slope stability is rarely reported. In this paper, an elastoplastic finite-element method using strength-reduction techniques is used to analyze the stability of special 3D geometric slopes. A typical 3D slope underlain by a weak layer with groundwater is described to validate the numerical modeling, safety factor values, and critical slip surface for the 3D slope. Furthermore, a series of special 3D slopes with various geometric configurations are analyzed numerically, and the effects of turning corners, slope gradient, turning arcs, and convex- and concave-shaped surface geometry on the stability and failure characteristics of slopes under various boundary conditions are discussed in detail.

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.

Research and Application of Slope Stability Analysis Method Based on Engineering Mechanics and Engineering Materials

2014 ◽  
Vol 886 ◽  
pp. 432-435
Author(s):  
Shao Jie Feng ◽  
Shi Guo Sun ◽  
Xue Fang Zhao ◽  
Liang Tan
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Three Dimensional ◽  
Field Method ◽  
Slope Stability Analysis ◽  
Analysis Method ◽  
Rock Mass Failure ◽  
Slope Rock

Considering the features of slope rock mass failure, this paper applies residual thrust method and linear programming theory on the basis of finite element method, to assess safety of each cell of slope rock mass in dangerous zone. According to the slip field method to determine three-dimensional slope slip surface, to deduce three-dimensional stability analysis method based on symmetry breaking, a C++ based 3D-slope program is developed for purposes of three-dimensional slope stability analysis. Finally get the most dangerous landslide geometry and its safety factor, In the paper, combining with the engineering examples, the calculating results are comfortable to the practical failure.

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.

General Slice Method Based on Rigorous Equilibrium to Solve the Factor of Safety

2012 ◽  
Vol 446-449 ◽  
pp. 1755-1763
Author(s):  
Ming Cheng Yang
Keyword(s):  
Shear Strength ◽  
Safety Factor ◽  
Shear Force ◽  
Factor Of Safety ◽  
Slip Surface ◽  
Reduction Factor ◽  
Equilibrium Equations ◽  
Surface Geometry ◽  
New Methods ◽  
Rigorous Method

For a general slice, force and moment equilibrium equations are developed, the recurrence equations of inter-slice force and inter-slice moment are derived, the general formulation based on rigorous equilibrium to solve the factor of safety is studied, hence, the theoretical framework of rigorous method of general slice is developed, rigorous method of vertical slice is a special case of it. Analyzing the applicability of Sarma’s method, two new inter-slice shear force equations are presented based on the compatible relationship among slice’s displacements by leading in the scaling parameter λ and inter-slice force function f(x),hey make the relationship between the inter-slice shear forces and slip surface geometry clear, and indicate that the reduction factor for shear strength along inter-slice boundaries varies from one boundary to the next depending on the geometry of the slices and the slip surface. The rigorous methods of general slice can be developed based on the modified inter-slice shear force equations, they think that the reduction factor for shear strength along inter-slice boundary is different from that for shear strength along slip surface. The example analysis indicates that the proposed new methods work better than Sarma’s method, the reasonable value of safety factor can be obtained by using them. Even if the shape of slice is varied, the proposed new methods can also give consistent values of safety factor and ensure that the iteration is stably convergent.

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