scholarly journals Slope Stability Analysis Based on Measured Strains along Soil Nails Using FBG Sensing Technology

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Hua-Fu Pei ◽  
Chao Li ◽  
Hong-Hu Zhu ◽  
Yu-Jie Wang
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Cross Section ◽  
Slip Surface ◽  
Axial Stress ◽  
Limit Equilibrium ◽  
Cost Effective ◽  
Slope Stability Analysis ◽  
Actual Condition ◽  
Soil Nails

In the past few decades, slope stability analysis using numerical methods is becoming a hot issue, but it is based on extremely ideal assumptions. Soil nailing technique, as one of the most cost-effective reinforcing methods, has already been widely used for reinforcing slopes. In this study, to evaluate the safety factor of a slope, the strains on soil nails were measured by fiber Bragg grating (FBG) sensor. Strains along soil nails in the same cross section of a slope can be computed using the measured wavelength shifts of FBG sensors. In order to evaluate the stability of a slope, an optimal model was proposed to search the potential slip surfaces based on measured strain values. Maximum sum of strains on soil nails at different elevations of the same cross section was taken as the objective. Positions of soil nails, circular slip surface, and boundary conditions of the soil nails were summarized and taken as constraints. Finally, safety factors can be computed using the searched slip surface regarding the axial stress of soil nails. This method combines the limit equilibrium methods with measured axial strains on site which can reflect the actual condition of field slopes.

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.

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.

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 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.

Evaluation of active earth pressure by the generalized method of slices

1998 ◽  
Vol 35 (4) ◽  
pp. 591-599 ◽  
Author(s):  
Zuyu Chen ◽  
Songmei Li
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Slope Stability Analysis ◽  
Pressure Limit ◽  
The Earth ◽  
Earth Pressures

The generalized method of slices, commonly used in slope stability analysis, can be extended to determine active earth pressures applied to various types of supports. The governing force and moment equlibrium equations are given. In a similar manner to slope stability analysis, the methods of optimization are used to define the critical slip surface that is associated with the maximum wall pressure. Examples show that the approaches give active earth pressures identical to the Rankine solution for gravity walls. For other types of support, such as anchored or strutted walls, the earth pressure is determined by assigning appropriate locations of the point of application on the wall. It has been found that applying the restrictions of physical admissibility is more vital in earth pressure problems than in slope stability assessments.Key words: earth pressure, limit equilibrium method, the method of slices, retaining walls.

Limit equilibrium slope stability analysis using the nonlinear strength failure criterion

2015 ◽  
Vol 52 (5) ◽  
pp. 563-576 ◽  
Author(s):  
Dong-ping Deng ◽  
Lian-heng Zhao ◽  
Liang Li
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Failure Criterion ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Current Method ◽  
Slope Stability Analysis ◽  
Strength Failure ◽  
Slope Safety

The limit equilibrium stability analysis of two- and three-dimensional slopes with the nonlinear failure strength criterion uses a number of variables to determine the normal and shear stress on the slip surface. The equation for the nonlinear strength failure criterion is expressed using a Taylor series after analyzing the stress of an elemental slice or column. Multivariate linear equations are then derived to determine these variables based on the force and moment equilibrium conditions the sliding body is subject to. The stress on the slip surface can also be obtained to calculate the slope safety factor. The validity of the current method was verified by comparing it with established examples. Charts were produced for slope stability analysis with the nonlinear strength failure criterion under general conditions using the current method. The results of this study show that the slope safety factor decreases with an increase in the geotechnical material parameter m in the nonlinear strength failure criterion. The results of the current method are in close correspondence with other traditional limit equilibrium methods and are more reliable than the Swedish method. The charts can be used to determine slope design parameters that meet specific requirements.

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.

An interslice force function for limit equilibrium slope stability analysis

1986 ◽  
Vol 23 (3) ◽  
pp. 287-296 ◽  
Author(s):  
K. Fan ◽  
D. G. Fredlund ◽  
G. W. Wilson
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Error Function ◽  
Soil Mass ◽  
In Situ Stress ◽  
Slope Stability Analysis ◽  
Element Analysis ◽  
Slope Inclination

The equations of statical equilibrium and the failure criterion for the soil are insufficient to render a slope stability analysis determinate. Generally, the problem is resolved by making assumptions regarding the interslice forces. Calculated safety factors generally do not vary widely as a result of different assumptions. However, difficulties are sometimes associated with the convergence of the nonlinear solution when assumptions deviate excessively from realistic in situ stress conditions.This paper presents the results of an elastic analysis for the computation of interslice normal and shear forces acting within a soil mass. The directions of the resultant interslice forces were computed using a two-dimensional, finite element analysis with constant strain elements. Simpson's method of integration was used to develop a function, f(x), describing the directions of the resultant interslice forces. The function was found to be bell-shaped with the peak occurring approximately at mid-slope (i.e., halfway between the crest and the toe). A generalized empirical function has been proposed. The equation takes the form of an extended error function in which the constants c and n are functions of the slope inclination, and the K-constant is a function of the slope inclination and the depth of the slip surface. Slope analyses using the proposed function show a line of thrust near the one-third point. No problems have been observed with convergence of the solution. Key words: slope stability, safety factor, method of slices, interslice forces, finite elements, interslice force functions, clay, slopes.

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.

scholarly journals On Slip Surface and Slope Stability Analysis

1975 ◽  
Vol 15 (3) ◽  
pp. 41-49 ◽  
Author(s):  
W.F. Chen ◽  
N. Snitbhan
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Slip Surface ◽  
Slope Stability Analysis
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