Rock slope stability and distributed joint systems

1992 ◽  
Vol 29 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Bruce J. Carter ◽  
Emery Z. Lajtai
Keyword(s):  
Factor Of Safety ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Probability Of Failure ◽  
Cumulative Distribution ◽  
Rock Slope Stability ◽  
Sensitivity Analyses ◽  
The Stability ◽  
Rock Wedge

A deterministic (GEOSLIDE) and a probabilistic (PROSLIDE) microcomputer code are introduced to aid in performing rock wedge analyses based on the limit equilibrium method. The deterministic code evaluates the stability of a single rock wedge formed by discontinuities in rock through three-dimensional vector algebra, GEOSLIDE undertakes a full kinematic analysis (daylighting and obstruction), analyzes both wedge and plane sliding, and provides for anchor designs and sensitivity analyses (cohesion, friction, and water forces). Through multiple stability analyses, PROSLIDE evaluates the probability of failure for a rock slope by examining the distribution of the factors of safety from all the potential sliding wedges formed by the discontinuities of the rock mass. The probability of failure is expressed as the ratio of kinematically free wedges that have a factor of safety less than unity to the total number of wedges, PROSLIDE can form and analyze as many as 2000 different pairs of discontinuities in less than 30 min using a 25 MHz 486 IBM-compatible computer. In a worked example, the probability of failure for a fixed slope strike and loading condition is shown to vary with the slope angle, following the characteristic 'S' shape of a cumulative distribution function. The effect of an anchor force is to spread the distribution over a wider range of the factor of safety (SF), pushing many wedges into a potential upslide situation and splitting the distribution about the failure zone of the stability diagram (−1 < SF < 1). Key words : rock slope, rock wedge, stability analysis, factor of safety, probability of failure, Monte Carlo simulation.

scholarly journals AN EVALUATION OF ROCK SLOPE STABILITY USING LIMIT EQUILIBRIUM ANALYSES

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Faridha Aprilia ◽  
I Gde Budi Indrawan
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Plane Failure ◽  
General Limit ◽  
The Stability ◽  
Equilibrium Analyses ◽  
Limit Equilibrium Analyses

The stability of rock slopes is controlled by several factors, such as the intact rock strength, discontinuity characteristics, groundwater condition, and slope geometry. Limit equilibrium (LE) analyses have been commonly used in geotechnical practice to evaluate the stability of rock slopes. A number of methods of LE analyses, ranging from simple to sophisticated methods, have been developed. This paper presents stability analyses of rock slopes at the Batu Hijau open mine in Sumbawa Barat using various methods of LE analyses. The LE analyses were conducted at three cross sections of the northern wall of the open mine using the Bishop Simplified, Janbu Simplified, Janbu Generalised, and General Limit Equilibrium (GLE) methods in Slide slope stability package. In addition, a Plane Failure (PF) analysis was performed manually. Shear strength data of the discontinuity planes used in the LE analyses were obtained from back analyses of previous rock slope failures. The LE analysis results showed that the rock slopes were likely to have shallow non-circular critical failure surfaces. The factor of safety (Fs) values obtained from the Bishop Simplified, Janbu Simplified, Janbu Generalised, and GLE methods were found to be similar, while the Fs values obtained from the PF method were higher than those obtained from the more rigorous methods. Keywords: Batu Hijau mine, Bishop Simplified, Janbu Simplified, Janbu Generalised, limit equilibrium analyses, general limit equilibrium, rock slope stability, plane failure.

scholarly journals STABILITY OF RUBBLE MOUND BREAKWATERS WITH A BERM

2012 ◽  
Vol 1 (33) ◽  
pp. 10
Author(s):  
Marcel Van Gent ◽  
Gregory M. Smith ◽  
Ivo Van der Werf
Keyword(s):  
Rock Slope ◽  
Slope Angle ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Test Results ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
The Stability ◽  
Rubble Mound Breakwaters ◽  
Rock Size

The stability of rock slopes with a horizontal berm has been studied by means of physical model tests. This paper is focussed on the rock slope stability of the slopes above and below the berm. By applying a berm the rock size can be reduced compared to the required rock size for a straight slope without a berm. This reduction can be significant for the slope above the berm. The influence of the slope angle (1:2 and 1:4), the width of the berm, the level of the berm, and the wave steepness have been investigated. Based on the test results prediction formulae have been derived to quantify the required rock size for rubble mound breakwaters with a berm.

More rapid analysis of rock slopes

1984 ◽  
Vol 21 (4) ◽  
pp. 678-683
Author(s):  
D. M. Cruden
Keyword(s):  
Factor Of Safety ◽  
Rock Slope ◽  
Rapid Analysis ◽  
Rock Slopes ◽  
Equal Area ◽  
Slope Analysis ◽  
The Stability ◽  
New Criterion ◽  
Spherical Projection ◽  
Rock Wedge

When the normals to two discontinuities forming a tetrahedral wedge in a rock slope lie in the opposite halves of a spherical projection divided by a diameter through the line of intersection of the discontinuities, sliding will take place down the line of intersection of the discontinuities if this is statically possible. This new criterion simplifies the analysis of the stability of rock wedges whose motion is driven only by gravity and resisted only by friction. A factor of safety can be simply calculated for all these wedges from plots of the normals to discontinuities on an overlay of a polar, equal-area spherical projection to which the great circles of a similar equatorial projection have been added. Key words: rock, slope analysis, rock wedge, graphical methods.

3D Analysis on the High Rock Slope Stability of Ningde Nuclear Power Plant, Fujian Province

2011 ◽  
Vol 368-373 ◽  
pp. 2843-2847
Author(s):  
Chang Liang Zhang ◽  
Ya Guo Zhang ◽  
Xiao Wei Zhang ◽  
Xiao Ning Deng ◽  
Tong Lu Li
Keyword(s):  
Finite Element ◽  
Nuclear Power ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Rock Slope Stability ◽  
Slope Ratio ◽  
Dimensional Finite Element ◽  
The Stability ◽  
Three Dimensional Finite Element

Ningde nuclear power plant in Fujian province is one of the national key construction projects of nuclear power, in order to insure the smooth progress of construction project, it needs to assess the rock slope stability which lies in the southeast of the living area. On the base of the rock architectural feature, the qualitative analysis, the three-dimensional limit equilibrium and the three-dimensional finite element are adopted to analyze the stability of the slope. The result of the qualitative analysis shows that most of the slope is stable, and part of it may fail after excavation. The result of the three-dimensional limit equilibrium and the three-dimensional finite element both illustrate that the slope is stable after excavation with slope ratio 1:0.25,1:0.50 and 1:0.75, and the stability factor rises with the decreasing of the slope ratio. At last, according to the above computing result, the 1:0.50 or the minor value is suggested to be adopted as the design slope ratio to excavate the slope.

scholarly journals Optimization of Embankment Widening with Different Soils

2019 ◽  
Vol 8 (3) ◽  
pp. 711-715
Keyword(s):  
Stability Analysis ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Slope Angle ◽  
Land Area ◽  
Huge Amount ◽  
Limit Equilibrium Methods ◽  
The Stability ◽  
The Cost ◽  
Different Soils

Due to increasing in the population and vehicular volume the existing roads are becoming inadequate. To overcome this problem, widening of existing roads or embankments are obtained, which required a huge amount of soils of suitable properties but due to industrialization and urbanization the availability of good soils are getting reduced because of which the construction should be carried out with unsuitable or weaker soils of inadequate properties and also the widening process involves accumulation of large land area which results in uneconomic of project. In this study three different soils are considered to analyze the influence of weaker soils on embankment widening which involves the stability analysis and reinforcement contribution analysis. Also study involves optimization of embankment widening using Different embankment sections with different slope angles ( via 1V:1H, 2V:1.5H, 2V:1H and 2.5V:1H ) and geo-synthetic reinforcement, which results in reductions of additional land required and backfill material but ensuring minimum factor of safety of 1.5. The analysis performed based on Limit equilibrium methods using SLOPE/W software. The results shows that the reinforcement mobilizes the stabilizing force in embankment which increases the stability and corresponding factor of safety of embankment and for the reinforced section the factor of safety value is a contribution of both reinforcement and shifted critical slip circle and percentage of contribution depends upon slope angle, soil properties & reinforcement. The cost analysis of embankment widening with different soils and different slope angles shows that steep section is the most economical section in all the cases

scholarly journals Methodology to evaluate rock slope stability under seismic conditions at Solà de Santa Coloma, Andorra

2009 ◽  
Vol 9 (6) ◽  
pp. 1763-1773 ◽  
Author(s):  
O. Mavrouli ◽  
J. Corominas ◽  
J. Wartman
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Slope Angle ◽  
Water Levels ◽  
Equilibrium Analysis ◽  
Rock Slope Stability ◽  
Ground Acceleration ◽  
Moderate Seismicity

Abstract. An analytical methodology is presented to evaluate rock slope stability under seismic conditions by considering the geomechanical and topographic properties of a slope. The objective is to locate potential rockfall source areas and evaluate their susceptibility in terms of probability of failure. For this purpose, the slope face of a study area is discretized into cells having homogenous aspect, slope angle, rock properties and joint set orientations. A pseudostatic limit equilibrium analysis is performed for each cell, whereby the destabilizing effect of an earthquake is represented by a horizontal force. The value of this force is calculated by linear interpolation between the peak horizontal ground acceleration PGA at the base and the top of the slope. The ground acceleration at the top of the slope is increased by 50% to account for topographic amplification. The uncertainty associated with the joint dip is taken into account using the Monte Carlo method. The proposed methodology was applied to a study site with moderate seismicity in Solà de Santa Coloma, located in the Principality of Andorra. The results of the analysis are consistent with the spatial distribution of historical rockfalls that have occurred since 1997. Moreover, the results indicate that for the studied area, 1) the most important factor controlling the rockfall susceptibility of the slope is water pressure in joints and 2) earthquake shaking with PGA of ≤0.16 g will cause a significant increase in rockfall activity only if water levels in joints are greater than 50% of the joint height.

scholarly journals Application of Slope Mass Rating System In Slope Stability Class Evaluation

2019 ◽  
Vol 9 (1) ◽  
pp. 3645-3649
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Rock Slope ◽  
Probability Of Failure ◽  
Rating System ◽  
Rock Slope Stability ◽  
Cut Slope ◽  
Stability Class ◽  
Slope Mass Rating ◽  
The Stability

The rock slope stability analysis is a challenging task in geotechnical engineering. The metasedimentary cut slope at Putrajaya-Cyberjaya Link was assessed using Slope Mass Rating (SMR) system in this study. The results of SMR calculation obtained in this study is 23.3. The results shows that, the slope stability class obtained is IV and the cut slope of the study area is in bad condition. The stability is known to be unstable and the probability of failure is 0.6 or 60%.

scholarly journals ENGINEERING GEOLOGICAL ASSESSMENT OF THE ROCK SLOPE STABILITY ALONG THE PROPOSED LERABIRE ROAD IN THE MERGASUR CITY, KURDISTAN, IRAQ

2020 ◽  
Vol 53 (2F) ◽  
pp. 65-82
Author(s):  
Rebaz Qader
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Slope Angle ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Stability Of Slopes ◽  
The Stability ◽  
High Degree ◽  
Marly Limestone ◽  
Failure Possibility

The study of slope stability along the proposed Lerabire road in the Mergasur town, in Erbil city, Kurdistan region of NE-Iraq is carried out. To evaluate the stability of slopes, twenty stations were selected along the mentioned road, two stations in the rock slopes of the Shiranish Formation, eleven stations in the Bekhme Formation, six stations in the Qamchuqa Formation, and one station in the Sarmord Formation. In this study, the stability of rock slopes has been evaluated by the Landslide Possibility Index system. The results of the Landslide Possibility Index category in the rock slopes along the proposed Lerabire road ranges from a very low to low for rock slopes in stations 1 and 2 (marl and marly limestone of the Shiranish Formation, Moderate for rock slopes in stations 3, 4 and 19 (limestone of the Bekhme Formation), High for rock slopes in the stations 5, 6, 7, 8, 9, 10, 11 (limestone of the Bekhme Formation), stations 12, 17 (limestone and marly limestone of the Qamchuqa Formation), station 20 (limestone of the Sarmord Formation and very high for rock slopes in the stations 13, 14, 15, 16 (limestone and marly limestone of the Qamchuqa Formation), station 18 (limestone of the Bekhme Formation). According to Landslide Possibility Index category, the hazard category is Low in station 1 in the Shiranish Formation, but in station 2, 3, 4 and 19 are Moderate, moreover, in the station 5, 11, 12, 17, 18 and 20 are high. The rock slope assessment indicated that the height of the slope face, slope angle, a high degree of weathering, and discontinuities spacing are the factors that increase the failure possibility. To prevent landslide the ditch method is used in the Shiranish Formation rock slopes, the reinforcement techniques are used in the Behkme Formation rock slopes and rock removal methods are used in Qamchuqa and Sarmord Formation rock slopes.

scholarly journals Probability Methods for Stability Design of Open Pit Rock Slopes: An Overview

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 319
Author(s):  
Musah Abdulai ◽  
Mostafa Sharifzadeh
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Probabilistic Analysis ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Probability Of Failure ◽  
Slope Stability Analysis ◽  
Rock Slope Stability ◽  
Open Pit ◽  
Rational Approach

The rock slope stability analysis can be performed using deterministic and probabilistic approaches. The deterministic analysis based on the safety concept factor uses fixed representative values for each input parameter involved without considering the variability and uncertainty of the rock mass properties. Probabilistic analysis with the calculation of probability of failure instead of the factor of safety against failure is emerging in practice. Such analyses offer a more rational approach to quantify risk by incorporating uncertainty in the input variables and evaluating the probability of the failure of a system. In rock slope engineering, uncertainty and variability involve a large scatter of geo-structural data and varied geomechanical test results. There has been extensive reliability analysis of rock slope stability in the literature, and different methods of reliability are being employed for assessment of the probability of failure and the reliability of a slope. Probabilistic approaches include Monte Carlo simulation (MCS), the point estimate method (PEM), the response surface method (RSM), first- and second-order reliability methods (FORMs and SORMs), and the first-order second-moment method (FOSM). Although these methods may be complicated, they provide a more complete definition of risk. Probabilistic slope stability analysis is an option in most commercial software; however, the use of this method is not common in practice. This paper provides an overview of the literature on some of the main probabilistic reliability-based methods available for the design of the rock slope in open pit mining. To demonstrate its applicability, the paper investigates the stability of a rock slope in an open pit mine in the Goldfields region, Western Australia. Two different approaches were adopted: deterministic stability analysis using two-dimensional limit equilibrium and finite element shear strength reduction methods using SLIDE and RS2 software, respectively, and probabilistic analysis by applying the MCS and RSM methods in the limit equilibrium method. In this example, the slope stability analysis was performed using the Spencer method with Cuckoo search optimization to locate the critical slip surface. The results obtained were compared and commented on.

Some difficulties associated with the limit equilibrium method of slices

1983 ◽  
Vol 20 (4) ◽  
pp. 661-672 ◽  
Author(s):  
R. K. H. Ching ◽  
D. G. Fredlund
Keyword(s):  
Slope Stability ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Stability Limit ◽  
Limit Equilibrium Method ◽  
Soil Conditions ◽  
Side Force ◽  
Limit Equilibrium Methods ◽  
Equilibrium Method ◽  
The Stability

Several commonly encountered problems associated with the limit equilibrium methods of slices are discussed. These problems are primarily related to the assumptions used to render the inherently indeterminate analysis determinate. When these problems occur in the stability computations, unreasonable solutions are often obtained. It appears that problems occur mainly in situations where the assumption to render the analysis determinate seriously departs from realistic soil conditions. These problems should not, in general, discourage the use of the method of slices. Example problems are presented to illustrate these difficulties and suggestions are proposed to resolve these problems. Keywords: slope stability, limit equilibrium, method of slices, factor of safety, side force function.

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