The weight of the slice of width b and height h having a unit dimension into the page is given by. Methods for analysis of slope stability are described and are illustrated by examples in. Slope stability calculation spreadsheet simplified. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. This program is used to perform slope stability analysis embankments, earth cuts. Sep 04, 20 slope stability analysis of earth dam by slip circle method.
Slope stability can be analyzed on different method limit equilibrium most used. Friction circle theory has been around for about 100 years and is probably the most accepted method of analyzing soil slope stability. Morgenstren and price method is used for analyzing the slope stability in moment eq uilibrium for general slip slope surface. Spreadsheet slope stability free software downloads and. Methods for analysis of slope stability are described and are illustrated by. Determination of critical slip surface in slope analysis. A genetic algorithm for solving slope stability problems.
The long slope of the face of a mountain is an example of this type, whereas finite slopes are limited in extent. 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. Slope stability free slope stability software download. Consequently, slope stability software became available soon after the advent of computers. Dec 01, 2014 the slip circle method of slices is commonly used in the analyses of slope stability and bearing capacity for multilayered ground. The circular and noncircular slip surfaces can be considered in this unit. Soil slope stability analysis using the friction circle. May 25, 2015 the use of the slip circle in the stability analysis of slopes open pdf. Calculate the factor of safety against shear failure along the slip circle shown. The introduction of powerful desktop personal computers in the early 1980s made it economically viable to develop commercial software products based on these. In this research, three metaheurestic algorithms were applied for the slope stability analyzing of three studied and selected cases from literature.
This method considers yield criteria and the stressstrain relationship. However, in the case of ground consisting of horizontal sandy layer, it is known that modified fellenius. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. Slope stability analysis with the finite element method indra noer hamdhan1, 2 abstract in the evaluation of slopes, the factor of safety values still remain the main indexes for finding out how close or far slopes are from failure. Noncircular slip circles optional if the user requires a noncircular slip surface then it can be prescribed in combination with the simplified method of analysis. Sometimes, the circle line slip surface is unrealistic similar to fig. If the lower soil layer is weaker, a circle tangent to the base of the weaker layer. Ordinary method of slices oms figure 2 shows a cross section of a slope. Two dimensional slope stability analysis slope stability can be analyzed on different method limit equilibrium most used assume on arc of circle fellenius, bishop non circular slope failure janbu limit analysis finite difference finite element more flexible. Among th em th e morgenstern and price method has been chosen for thi s parametric stud y. Slope stability analysis by swedish slip circle method using. The development of methods for slopestability analysis was initially about quantifications of clay. Introduction to slope stability and protection course no. Slide2 is a powerful, userfriendly, 2d slope stability analysis program using limit equilibrium method.
The method of stability analysis used see section 6. Bishops simplified method the circular slip surface. Finding the safety factor of an embankment using a limit equilibrium method requires a search algorithm to find the representative slip circle. Also shown are the free body diagram and the force polygon for slice i, where 1 i n. Figure 1 method of slices simplified bishop method circular slip surface.
Cads reslope is a leading slope stability software package for calculating the factor of safety of earth slopes in accordance with both the eurocodes and british standards the basic software module deals with unreinforced slope analysis using bishops simplified method and circular slip. The most common formulation for f assumes the factor of safety to be constant along the slip surface, and it is defined with respect to the force or moment equilibrium. Petterson 1955 first applied the circle method to the analysis of a soil failure in. The results include a grid of stability factors at each circle centre, as well as the coordinate and stability factor of the critical circle. Slide2 can be used for all types of soil and rock slopes, embankments, earth dams, and retaining walls. Ordinary method of slices o firm soft firm slip surface fill c i r c l e r r a d i u s r.
The approach of assuming circular slip surfaces was introduced in 1916 and presented as a fully. Recommended stability methods goms is conservative and gives unrealistically lower fs than bishop or other refined methods gfor purely cohesive soils, oms and bishop method give identical results gfor frictional soils, bishop method should be used as a minimum grecommendation. Arbitrarily draw a possible slip circle actually on arc of a radius r and locate the phreatic surface. 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. Slope satiability by bishops method using excel sheets. The evaluation can be done my means of conventional slip circle analysis the limit equilibrium methods or by means. The use of the slip circle in the stability analysis of. Slope stability analysis is a static or dynamic, analytical or empirical method to evaluate the stability of earth and rockfill dams, embankments, excavated slopes, and natural slopes in soil and rock. The analysis in question, which assumed that the slide occurred along a circular arc, resulted later in the development of the swedish slip circle method also called the a 0 method. 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. Slope performs twodimensional slope stability analysis to study circular or noncircular slip surfaces. Slope stability analysis is performed by the limit equilibrium approach. The program uses the method of slices and offers a variety of established methods for calculating interslice forces.
The common methods for the analysis of a slope s stability are culmann method, ordinary method of slices and bishop method of slices. The use of the slip circle in the stability analysis of slopes open pdf. This revised method required an iterative procedure to solve and so it was suited to computer methods where this could be automated. Pdf slope stability analysis methods danial salajegheh. The bishops simplified method was initially developed for circular slip surfaces, but the. Let efb be the slope and akb be the slip circle drawn with center o and radius r 20 m. The slope length depends on the height of the dam or embankment. The cases are discussed below pham and fredlun 2003 presented a paper on the local slope failure. The slip surface is considered as circular bishop, felleniuspetterson, janbu, morgensternprice o. Determination of the critical slip surface in slope stability. Morgenstren and price method is used for analyzing the slope stability in moment eq uilibrium for general slip slope. Chapter 7 slope stability analysis geotechnical design manual page 5 of 17 table 7. Slope stability calculation spreadsheet simplified bishop. Here in the swedish circle method, potential failure surface is assumed to be cylindrical in shape i.
To simplify the handmade calculation the circle slip surfaces of the individual blocks have been replaced by lines. The verification methodology of the slope stability is done according to. Slide2 analyzes the stability of slip surfaces using vertical slice or nonvertical slice limit equilibrium methods like bishop, janbu, spencer, and sarma, among others. The slopes of embankments and earth dams are examples of finite slopes. Slope stability analysis is an important area in geotechnical engineering. Methods of analysis of stability of slope the following methods are used for the analysis of stability of slopes. Fhwa nhi06088 6 slope stability soils and foundations volume i 6 3 december 2006 6. They are certainly major factors in cut slope stability and in. Important details of stability analyses location of critical slip surfaces examination of noncritical shear surfaces. Slope stability optimization with noncircular slip surface.
Slope stability causes of instability, analysis methods. Therefore, optimizing these problems needs robust algo rithms. Slope stability is an extremely important consideration in the design and. Methods of slope stability analysis o limit equilibrium method o limit analysis method o numerical methods we will consider only the limit equilibrium method, since it is the oldest and the mostly used method in practice. Slope stability analysis spreadsheet, method of slices slope stability analysis, slope stability analysis software free download, ordinary method of slices spreadsheet, bishop slope stability, slope stability analysis examples, factor of safety calculation for slope stability, slope stability analysis methods pdf, swedish method of slices example. The slope stability is calculated using felleniuspetterson method and bishops simplified method the circular slip surface. Use the appropriate shear strength of sections of the arc in each stratum. The stability condition of slopes is a subject of study and research in soil mechanics. Hajiazizi and tavana 17 used an optimization method for 3d slope stability. Use the friction circle method to find the factor of safety with respect to cohesion.
The side slopes of an earthen dam should be safe against shear failure. Out of the various methods of stability analysis of slopes, swedish slip circle method is commonly used in practice. Determination of the critical slip surface in slope. These methods include fellenius or swedish slip circle analysis, the bishop horizontal or constant inclined interslice. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. An overview on methods for slope stability analysis. Bishops methods are still routinely used in slope stability analysis software to this day. Description of the swedish slip circle method for slope stability analysis and solved example. Slope stability analysis with the finite element method. Download code slope stability calculation spreadsheet simplified bishop method.
This paper aims an overview on various methods of slope. Pdf an overview on methods for slope stability analysis. Theory of slope stability portland state university. Individual slip surfaces can be analyzed, or search methods can be applied to locate the critical slip surface for a given slope. 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. It performs twodimensional slope stability analysis using the method of slices and presents the results in a clear graphical format. The calculation of slope stability safety factors is a routine.
However, for unstable slopes in which the location of failure slip surface is critically. Verification analysis of the slope stability program. Slide2 most comprehensive 2d slope stability software. The slip surface that has the lowest factor of safety is considered to be the critical failure surface. Evaluation of critical slip surface in limit equilibrium analysis of. Slide2 includes builtin finite element groundwater seepage analysis, probabilistic analysis, multiscenario modeling, and support design. Injection methods vegetation thermal treatment bridging removal and replacement of the sliding mass slope stability charts use and applicability of charts for analysis of slope stability averaging slope inclinations, unit weights, and shear strengths soils with.
This method is extensively used in more complex problems of slope stability and where earthquake and vibrations are part of total loading. The speci c assumptions made are features of the speci c method. Use the following guide for positioning the circle. For all three cases of study, a noncircular slip surface is considered. Impact of waterlevel variations on slope stability diva. Various methods are available for slope stability analysis. In this handout, we will focus our attention on these two methods. Pdf a parametric study on slope stability of earthen dam. Method of slices for slope stability analysis general. In the 1st stage the stability of the slope is calculated and in the 2nd stage the stability of an anchored slope is calculated. Swedish slip circle method factor of safety for the slice is equal to the ratio of the resisting moment i i i. Y p y r epresents the joint probability density function and the.
To evaluate the stability of a slope by limit equilibrium methods, it is necessary to perform calculations for a considerable number of possible slip surfaces in order to determine the location of the critical slip surface and the corresponding minimum value of f. It is based on lower bound and upper bound theorems for bodies of elastic perfectly plastic materials. The free body diagrams and force polygons for two differ. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. Methods of analyzing slope stability simple methods of analysis slope stability charts spreadsheet software.
Slope stability analysis of earth dam by slip circle method. 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. Evaluation of minimum factor of safety in slope stability analysis. Slope provides an easy and accurate way to study a slip surface to find factors of safety against failure, and to check the improvements from reinforcement.
Slope stability analysis limit equilibrium or the finite. Comparison study between traditional and finite element methods. Bells method fellenius method the ordinary method of slices. You can also apply partial factors, including ec7, with. Water free fulltext a modeling platform for landslide stability. 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. Most textbooks on soil mechanics include several methods of slope stability analysis. Practical slip circle method of slices for calculation of. Jul 29, 20 conclusions for the practical use of the finite element method are also given. In this study, a new meshfree, particlebased numerical method in geotechnical engineering.
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