scholarly journals Upper Bound Limit Stability Analysis for Soil Slope with Nonuniform Multiparameter Distribution Based on Discrete Algorithm

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhen Wang ◽  
Xumeng Yang ◽  
Ang Li
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Upper Bound ◽  
Limit Analysis ◽  
Slip Surface ◽  
Open Pit ◽  
Calculation Error ◽  
Soil Slope ◽  
Stability Coefficient ◽  
Upper Bound Limit Analysis

Slope stability analysis is a core issue in geotechnical engineering. This paper proposes a method of upper bound limit stability analysis for a slope with multiparameter coordinated variation based on the comprehensive consideration of the nonuniform distribution of slope soil parameters. This method starts from the perspective of energy balance, establishes a slope failure mechanism which meets velocity separation requirements, deduces its calculation formula for external force power and internal energy dissipation power, develops a cycle program for the most dangerous slip surface searching and stability coefficient calculation through computer programming technology, and finally forms a calculation method of upper bound limit stability analysis for the soil slope with nonuniform multiparameter distribution. At the same time, this method takes a dump slope in an open-pit mine as the engineering background, considers the nonuniformity of density, cohesion, and internal friction angle of the slope soil under subsidence, applies upper bound limit analysis to analyze the slope stability, and evaluates the accuracy of analysis results by using the residual thrust method. The results show that upper bound limit analysis has highly accuracy in stability coefficient calculation; compared with the residual thrust method, the stability coefficient calculation result by upper bound limit analysis is a strict upper bound solution, and the calculation error is easy to be estimated and eliminated. Simultaneously, the most dangerous slip surface obtained by upper bound limit analysis can fully satisfy the velocity separation requirement and has a greater engineering reference value.

scholarly journals Comparative study of material point method and upper bound limit analysis in slope stability analysis

2020 ◽  
Vol 2 (1) ◽  
pp. 44-57
Author(s):  
Lianheng Zhao ◽  
Nan Qiao ◽  
Zhigang Zhao ◽  
Shi Zuo ◽  
Xiang Wang
Keyword(s):  
Stability Analysis ◽  
Upper Bound ◽  
Limit Analysis ◽  
Slope Failure ◽  
Slip Surface ◽  
Material Point Method ◽  
Material Point ◽  
Critical Slip Surface ◽  
The Stability ◽  
Upper Bound Limit Analysis

Abstract The upper bound limit analysis (UBLA) is one of the key research directions in geotechnical engineering and is widely used in engineering practice. UBLA assumes that the slip surface with the minimum factor of safety (FSmin) is the critical slip surface, and then applies it to slope stability analysis. However, the hypothesis of UBLA has not been systematically verified, which may be due to the fact that the traditional numerical method is difficult to simulate the large deformation. In this study, in order to systematically verify the assumption of UBLA, material point method (MPM), which is suitable to simulate the large deformation of continuous media, is used to simulate the whole process of the slope failure, including the large-scale transportation and deposition of soil mass after slope failure. And a series of comparative studies are conducted on the stability of cohesive slopes using UBLA and MPM. The proposed study indicated that the slope angle, internal friction angle and cohesion have a remarkable effect on the slip surface of the cohesive slope. Also, for stable slopes, the calculation results of the two are relatively close. However, for unstable slopes, the slider volume determined by the UBLA is much smaller than the slider volume determined by the MPM. In other words, for unstable slopes, the critical slip surface of UBLA is very different from the slip surface when the slope failure occurs, and when the UBLA is applied to the stability analysis of unstable slope, it will lead to extremely unfavorable results.

Upper Bound Limit Analysis of Passive Earth Pressure of Cohesive Backfill on Retaining Wall

2013 ◽  
Vol 353-356 ◽  
pp. 895-900 ◽  
Author(s):  
Xin Rong Liu ◽  
Ming Xi Ou ◽  
Xin Yang
Keyword(s):  
Upper Bound ◽  
Limit Analysis ◽  
Slip Surface ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Friction Angle ◽  
Cohesive Soil ◽  
Passive Earth Pressure ◽  
Simple Method ◽  
Upper Bound Limit Analysis

In view of the shortage of using classical earth pressure theories to calculating passive earth pressure of cohesive soil on retaining wall under complex conditions. Based on the planar slip surface and the back of retaining wall was inclined and rough assumption, the calculation model of passive earth pressure of cohesive backfill under uniformly distrubuted loads was presented, in which the upper bound limit analysis was adopted. Meanwhile it was proven that the prevailing classical Rankine’s earth pressure theory was a special example simlified under the condition of its assumptions. For it’s difficult to determine the angle of slip surface , a relatively simple method for calculating the angle was proposed by example. And the influence of angle of wall back , friction angle of the interface between soil and retaining wall, cohesion force and internal friction angle of backfill soil to planar sliding surface and passive earth pressure were analyzed. Some good calculation results were achieved, these analysis can provide useful reference for the design of retaining wall.

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.

Development of Slope Stability Evaluation Process of Frozen Soil in Coupling Temperature Field

2012 ◽  
Vol 446-449 ◽  
pp. 1948-1956
Author(s):  
Zhi Yun Liu ◽  
Jian Bing Chen ◽  
Long Jin ◽  
Jian Xu
Keyword(s):  
Temperature Field ◽  
Stability Analysis ◽  
Slope Stability ◽  
Soil Temperature ◽  
Slip Surface ◽  
Slope Stability Analysis ◽  
Frozen Soil ◽  
Critical Slip Surface ◽  
Cold Region ◽  
Stability Coefficient

The slope stability analysis in cold region is special for its non-uniform temperature field. Considering the special characteristic of the slope in cold region, the physical parameters of frozen soil are treated in this paper as the connection between temperature field and stress field. The temperature influences mechanical properties of frozen soil and forms freezing-thawing interface in the slope, which make great influence on the stability of slope. The critical slip surface searching algorithm for cold region is developed and the moment center solution method in the computation of slope’s stability coefficient is also improved. The critical slip surface and stability of 4m subgrade with 1: 1.5 slopes under different soil temperature condition is computed using the developed frozen subgrade stability computation program. The results shows that the line segment type slip surface is more accuracy than circle type slip surface in cold region slope stability analysis; moreover, the minimum stability coefficient of frozen subgrade does not happen in tenth months when the thawing soil goes to deepest, but show in the early time of warm season, forming the phenomenon of thaw slumping. And it is also found that the occurring time of yearly minimum landslide stability coefficient postpones as the decreasing of soil temperature.

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.

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