Seismic slope safety determination of critical slip surface using acceptability criteria a thesis submitted to the university of london in partial fulfillment for the degree of doctor of philosophy. H height of the overall slope or of each bench 60 m or 20 m respectively. Fellenius developed a method for stability analysis of a slope assuming a circular failure surface, which is known as the swedish circle method. Evaluation of minimum factor of safety in slope stability analysis. Symbol parameter dimensions f factor of safety against sliding along sheet joint calculated h height of the overall slope or of each bench 60 m or 20 m respectively. May 29, 2018 in this video i have talked about the friction circle method to check the stability of the soil on finite slope. Geoslope international ltd, calgary, alberta, canada.
Namdar 2010 presented the threewedge method for stability analysis of slope. Slope stability analysis geotechnical design manual m 4603 chapter 74 december 2006 slope stability analysis detailed assessment of the groundwater regime within and beneath the slope is also critical. Using a unified approach to address a medley of engineering and construction problems, slope stability analysis and stabilization. Brains objective is to combine experience, expertise and numerical results into one forecast.
The research presented in this thesis focuses on investigating and quantifying the effects of soil. The slip circle method of slices is commonly used in the analyses of slope stability and bearing capacity for multilayered ground. The user interface and analysis options are almost identical to the generalised slope analys is module except for the ability to define a slip surface of any general shape. Presently, the theory and software for twodimensional slope stability are rather mature, but there are still some important and new findings which will be discussed in this chapter. Application note slope stability analysis worked example. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. However, in the case of ground consisting of horizontal sandy layer, it is known that modified fellenius.
A very popular numerical method of slope stability estimation is shear strength reduction technique ssr. The limit equilibrium method is the most common approach for analyzing slope stability in both two and three dimensions. The main objectives of slope stability analysis are finding endangered areas, investigation of potential failure mechanisms, determination of the slope sensitivity to different triggering mechanisms, designing of optimal slopes with regard to safety, reliability and economics, designing possible remedial measures, e. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. Aug 06, 2014 download spreadsheet to calculate slope stability calculation. If for a specific slip circle the factor of safety obtained from the.
Considering a slip surface, the factor of safety f m defined with respect to moment is given by. This method of slope stability analysis is not widely used since it has been. New slope stability considerations for deep open pit mines. The effective stress principle and basic considerations of slope stability, including design factors of safety, are discussed briefly.
Slope stability slip surface using variational methods. Determination of the critical slip surface in slope. Modifications to the dfp method were found to be essential for successful implementation of the minimization procedure. The finite element stresses for the different slip circles are. Friction circle theory has been around for about 100 years and is probably the most accepted method of analyzing soil slope stability. For a circular failure surface, the centre of the circle is. Soil slope stability analysis using the friction circle. The finite element method needsadditional information. Slope stability analysis under combined failure criteria article pdf available in the open civil engineering journal 101. Fhwa nhi06088 6 slope stability soils and foundations volume i 6 3 december 2006 6. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. Our analyses has looked at peak values, residual values and variations of the strength and shear angles that would reduce stability to values of 1.
It also highlights some of the differences in approach to that adopted by the limit equilibrium method of slices. These methods are developed on the assumption that the plane of failure is circular arc, apart from the culmann method that assumes a plane surface of failure through the toe of the slope. Pdf in the current practice, to determine the safety factor of a slope with twodimensional circular potential failure surface, one of the. Strength reduction stability geoslope international. Generalised framework of limit equilibrium methods for slope stability analysis. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes.
Materials bishop probabilistic random field method. Fundamentals and methods presents basic principles for the safe design of constructed or natural earth slopes. In this synopsis, variational method is used to determine the slope stability slip surface based on ordinary method of slices without pore pressure and not circular for the time being. Slope stability analysis of soil slopes using the nonvertical slice method proposed by sarma noncircular slip. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo. The influence of root trees on slope stability was studied.
This engineer manual em provides guidance for analyzing the static stability of slopes of earth and rockfill dams, slopes of other types of embankments, excavated slopes, and natural slopes in soil and soft rock. The use of the slip circle in the stability analysis of slopes open pdf. Stability analysis of rock slopes using the finite element. The basis for most methods of slope stability analysis can be traced back to 1922, when the geotechnical commission was appointed by the swedish state railways to investigate solutions following a costly slope failure. Slope stability when the final fill elevations are attained and 3. Slope stability during interim fill phase development. Pdf investigation of stability of slopes under drawdown. The limitation of limit equilibrium method in slope stability analysis has been demonstrated by krahn 2003. Fellenius method the center of the initial critical circle, o, is assumed to be the.
Advanced numerical techniques in rock slope stability analysis applications and limitations pdf, davos, switzerland. The geological strength index, gsi, relates the failure criterion to geological observations in the field. Intro to slope stability analysis r ced engineering. Slopes in mountainous regions require cohesion 8 undrained short term slope failure in clay. Pdf slope stability analysis under combined failure criteria.
New slope stability considerations for deep open pit mines therefore appropriate that new attention should be paid to the effects of stresses on the stability of the slopes of these mines. Soil slope stability analysis 339 isfied for each and every slice, it is also satisfied for the entire mass. Slope stability analysis by the limit equilibrium method. Impact of waterlevel variations on slope stability diva portal. The aim of slope stability analysis of any natural or manmade slope is to determine the failure surface that has the lowest factor of safety. New slip circle method for analysis of slope stability and bearing capacity. Evaluation of minimum factor of safety in slope stability. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of determining, relatively unambiguously, whether a.
It is possible, and in many cases desirable, to combine the. Level 111 analyses are often completed using the xstabl method of slices interactive program for soil and the federal highway administrations rock slope stability analysis method for rock slopes. Chapter 10 slope stability analysis nysdot geotechnical page 106 january 21, 2014 design manual 10. May 25, 2015 the analysis of the stability of general slip surfaces authors. Use the appropriate shear strength of sections of the arc in each stratum. The development of methods for slopestability analysis was initially about.
The soil has three basic properties that are fundamental to the analysis. New methods and insight, second edition provides helpful practical advice and design resources for the practicing engineer. Mar 21, 2016 friction circle method the friction circle method of slope analysis is a convenient approach for both graphical and mathematical solutions. Application note slope stability analysis worked example 1 introduction this note describes the typical steps followed in setting up and analysing a slope stability problem with limitstate. In their study, changes in the factor of safety of slope and slip surface were investigated. By definition, the factor of safety of a slope is the ratio of actual soil shear. You can also include faults and discontinuity planes in. Detailed pieziometric data at multiple locations and depths within and. For an additional 9 years he was a principal advisor to.
In this equation the moments have been taken about the centre of the circle. The tatter method apparently is the most successful a discussion of ways. The slip surface that has the lowest factor of safety is considered to be the critical failure surface. Slope stability during excavation prior to waste placement. Locating the critical failure surface in a slope stability analysis by genetic algorithm. Slope instability may occur suddenly, as the slope is being excavated, or after the.
Pdf in the current practice, to determine the safety factor of a slope with two dimensional circular potential failure surface, one of the. Figure 1 is a line forming a tangent to the circle at point a. Slope stability verification manual deep excavation llc page 11 e. Limit equilibrium is the most widely used method for stability analysis. Stability of slopes is usually analyzed by methods. The use of the slip circle in the stability analysis. To predict the stability of a natural slope more accurately, especially the marginally stable one, the effects of soil variability and vegetation needs to be taken into account. Out of the various methods of stability analysis of slopes, swedish slip circle method is commonly used in practice. The research presented in this thesis focuses on investigating and quantifying the effects of soil variability and vegetation on the stability of natural slopes. Stability analysis of slopes with surcharge by lem and fem.
Includes recommendations for analysis, design practice, design charts, tables, and more. New slip circle method for analysis of slope stability and. Practical slip circle method of slices for calculation of. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. Effects of water on slope stability university of kentucky. Analysis of slope stability for soil slope the factor of safety has minimum value of 1. Detailed pieziometric data at multiple locations and depths within and below the slope will likely be needed. Slope stability analysis by swedish slip circle method. Investigation of stability of slopes under drawdown conditions article pdf available in computers and geotechnics 342. Friction circle theory has been around for about 100 years and is probably the most accepted method of. The common methods for the analysis of a slope s stability are culmann method, ordinary method of slices and bishop method of slices. Slope stability causes of instability, analysis methods. Pdf determination of slope safety factor with analytical solution.
Swedish slip circle method factor of safety for the slice is equal to the ratio of the resisting moment i i. Procedia engineering 46 2012 27 a 38 18777058 2012 the authors. Matlab script for slope stability calculations with comsol. Slide is a 2d limit equilibrium slope stability program for evaluating the safety factor or probability of failure. Slope stability demonstration 1 slope stability demonstration this document describes the stability analysis of a proposed soil slope using slide 5.
Excavation slope instability may result from failure to control seepage forces in and at the toe of the slope, too steep slopes for the shear strength of the material being excavated, and insufficient shear strength of subgrade soils. Civilax is the knowledge base covering all disciplines in civil engineering. In addition to the threelevel method, this guide discusses the forest planning process. This paper aims an overview on various methods of slope stability on the basis of assumptions, factor of safety calculation, soil conditions, soil types, applicability of output of the method with its limitations. This report presents the results of the slope stability analyses for the permitlevel marana regional landfill design. This is an educational platform set up iit bombay graduates with an aim to prepare you for competitive exams like gate, ese, etc. This master thesis focuse on natural slope and embankment slope stability analysis with the limit equilibrium method computer program slope w and the finite element method computer program plaxis 2d and comparison of a the analyzed result. An overview on methods for slope stability analysis.
Full text pdf 79k abstracts references17 full text pdf. The easier methods of rankine and culmann that assume a flat slip plane often produce dangerously inaccurate solutions and do not lend themselves to compound slope situations. This limitation is caused by the absence of a stress. For this method, the failure surface is assumed to be the arc of a circle as shown in figure 67 and the factor of safety against sliding along the failure surface is defined as the ratio of the moment of the total available resisting forces on the trial failure surface to the net moment of the driving forces due to the embankment weight, that is. Slope stability analysis with the finite element method. The derivations and effects of seepage forces and rapid. Complex geology slope stability analysis by shear strength. The factor of safety f in the method of slice is expressed as. Slope stability can be analyzed using one or more of the following.
The swedish slip circle method assumes a circular failure interface, and. The use of the slip circle in the stability analysis of slopes. Pdf an overview on methods for slope stability analysis. Slope stability software for soft soil engineering. Next the use of the slip circle in the stability analysis of slopes authors. Duncan 1996 illustrated that the finite element method can be used to analyze the stability and deformations of slopes. Slope stability analysis by swedish slip circle method using. Rules of thumb and easy method of estimating slope stability geology and soils information needed from site or soils database check appropriate loading conditions seeps, rapid drawdown, fluctuating water levels, flows select values to input for. The approach of assuming circular slip surfaces was introduced in 1916 and presented as a fully. It is shown that using the ordinary method of slices gives approximately the same shape slip surface for. This master thesis focuse on natural slope and embankment slope stability analysis with the limit equilibrium method computer program slopew and the finite element method computer program plaxis 2d and comparison of a the analyzed result. New slip circle method for analysis of slope stability and bearing capacity takashi tsuchida, kenta mizuno, hideto hikiyashiki 1 in japanese 2 in japanese 3 in japanese.
Here in the swedish circle method, potential failure surface is assumed to be cylindrical in shape i. An introduction to slope stability and protection j. Various methods are available for slope stability analysis. The limiting values are then reused with the slope profile being modified to include a repair using baled waste tires. The method of slice bishop, fellenius is the most commonly used soil slope stability method, where the soil mass above an assumed slip surface is divided into vertical slices refer to fig. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. Locating the critical failure surface in a slope stability. Stability analysis of finite slopes using the swedish circle method. Analytical solution and searching critical slip surface with.
Use the following guide for positioning the circle. The total weight w of the mass above the trial circle acting through the centre of mass. The objective of the study is to find out the factor of safety of the given slope under static and dynamic loading earthquake condition using swedish circle method, bishop stability method. They are certainly major factors in cut slope stability and in. The calculation of slope stability safety factors is a routine practice. Griffiths and lane 1999 illustrated that the finite element method represents a powerful alternative method for slope stability analysis which is accurate, adaptable and requires less assumptions, especially concerning the. They were mostly based on an approach that flows naturally from the definition of slope factor of safety, and is now commonly referred to as the shear strength reduction ssr technique.
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