Determination of slope safety factor with analytical solution and. Bishops simplified method slope stability soil mechanics. Various methods are available for slope stability analysis. Finally, several case studies of slope stability analysis are summarized. Slopes in mountainous regions require cohesion 8 undrained short term slope failure in clay. Slope stability analysis spreadsheet laobing kaisuo. Application note slope stability analysis worked example 4. Since, ec7 does not have a special provision for the problem of a footing on the crest of slope, the question whether it is a bearing capacity or a slope stability problem remains. Slope stability for a cohesive and frictional soil 11 1 slope stability for a cohesive and frictional soil 1. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. Slope stability is the resistance of inclined surface to failure by sliding or collapsing. How does the slope angle play a role in slope stability.
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. The aim of this study is to determine the factor of safety fos of. Soils and foundations testing experience theory lesson 06 chapter 6 slope stability. Intro to slope stability analysis r ced engineering.
Taylors stability number if the slope angle, height of embankment h, the effective unit weight of material, angle of internal friction, and unit cohesion c are known, the factor of safety may be determined. Rock slope stability analysis ubc eoas university of british. Taylor 1937 conceived the idea of analyzing the stability of a large number of slopes through a wide range of slope angles and. Example plot of allowable shear stress unit tractive force for cohesive materials. With the development of cheaper personal computer, finite element method has been increasingly used in slope stability analysis. Mar 21, 2016 taylors stability number if the slope angle, height of embankment h, the effective unit weight of material, angle of internal friction, and unit cohesion c are known, the factor of safety may be determined. 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. The infinite slope failure mode is an example of an internal stability problem. For more free video tutorials covering slope stability and soil mechanics. The calculator searches the circular slip surface for which the factor of safety is minimal. 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 example problems consist of 1 a simple slope, 2 an embankment on a very strong foundation, 3 an embankment on a relatively weak foundation, 4 an excavated slope. Designing a stable slope includes field investigation, laboratory investigation, and construction control. Chapter 10 slope stability analysis nysdot geotechnical page 1011 january 21, 2014 design manual 10. Slope stability is an extremely important consideration in the design and. Rock slope stability analysis utilization of advanced numerical techniques. In this video we introduce bishops simplified method and the. Evaluation of minimum factor of safety in slope stability analysis. Slope stability verification manual deep excavation llc page 11 e.
An overall stability situation is where there is loss of overall stability of the ground and associated structures, i. Calculate the factor of safety f against sliding along the potential failure surface qs. Third, finding the correct method of stability analysis solves only part of the design problem. Ru bbar and shansep soil strength pdf gsz page 2 of 8 3 case 1 ru only in this case, the porewater pressure condition is assumed to be described with an ru of 0. The quantitative determination of the stability of slopes is necessary in a number of engineering activities, such as.
An overview on methods for slope stability analysis. Apr 28, 2018 swedish circle method, mumbai university solved example. Slope stability analysis of peat landslides has been undertaken in relatively few cases. Example application 1 slope stability for a cohesive and. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement.
Nov 04, 2014 for more free video tutorials covering slope stability and soil mechanics. This calculator determines the factor of safety for a soil slope. Slope stability evaluations by limit equilibrium and finite. Manual em 111021902, department of the army, corps of engineers, washington, dc. Slope stability analysis by the limit equilibrium method books. In this video we introduce bishops simplified method and the expression of the factor of safety. Fundamentals and methods presents basic principles for the safe design of constructed or natural earth slopes. Free download slope stability analysis spreadsheet, method of slices slope stability analysis, slope stability analysis software free download, slope stability analysis examples, ordinary method of slices spreadsheet, slope stability analysis methods pdf, factor of safety calculation for slope stability, swedish method of slices example, slope analysis pdf, incoming search terms. Surcharge pressures on slope for example problem b shortterm stability computation series no. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. Comparison with hand calculations geoslope international.
Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. Geoslope international ltd, calgary, alberta, canada. Pdf slope stability analysis using limit equilibrium method in. Before the calculation of slope stability in these methods, some assumptions, for example, the side forces and their directions, have to be given out artificially in order to build the equations of equilibrium. 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 limit equilibrium method is the most common approach for analyzing slope stability in both two and three dimensions. Step 4 analyze the stability of the slope if a groundwater flow calculation is specified first to establish the phreatic surface, and then the stability of the slope is calculated. Slope stability analysis by the limit equilibrium method. The term slope means a portion of the natural slope whose original profile has been modified by artificial interventions relevant with respect to stability. The calculation of slope stability safety factors is a routine practice. The slopes of embankments and earth dams are examples of finite slopes.
Coe 1994 example allowable tractive forces sheetflow. Slope stability is controlled by relief material strength soil water content vegetation. It is a slightly modified javascript clone of the slope stability software stabr ver. The term landslide refers to a situation of instability affecting natural slopes and involving large volumes of soil. A slope stability calculation, the be used to calculate approximate factor of safety fos values slip planes whilst changing other the infinite slope method assumes the following. Slope instability may occur suddenly, as the slope is being excavated, or after the. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. Vertical crack for example problem b shortterm stability computations. It uses the bishop modified andor ordinary method of slices for a 2dimensional setting. Slope, a limit equilibrium slope stability analysis program, was used. 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. To overcome its shortcomings, this paper combined hoekbrown criterion and limit equilibrium method and proposed an equation for calculating the safety factor. The purpose of this illustrative example is to show how anchors can be used to improve the stability of a system. Slope stability analysis is performed to assess the safe design of a humanmade or natural slopes e.
Choice of slope stability calculation method another important choice, which depends on the means that can be used, is that between a method that models the entire soil mass and a method defined locally, along a fracture surface, for example. 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. The long slope of the face of a mountain is an example of this type, whereas finite slopes are limited in extent. Pdf slope stability analysis methods danial salajegheh. The method of stability analysis used see section 6. A series of seven example slope stability problems for the computer program, utexas, is presented. For calculation model of slope stability under the dsr technique, the general nonlinear mohrcoulomb mc criterion is used to describe the shear failure of slope. Trevor orr trinity college dublin convenor tc250sc7eg3. The basic approach is determining a factor of safety. The setback gradient line measured from the toe of the slope, or channel assuming the location of the toe remains fixed with time.
Global stability with relict slip surface in this scenario, the presence of the relict slip surface was assumed. Application of the finite element method to slope stability. Internal stability can be assured through project specifications by requiring granular materials. November 1984 with the computer program utexas stephen g. What are the factors that influence slope stability. Pdf estimation of slope stability using twoparameter. Slope failure is the movement of mass on slope falls, slides, flows landslide. Chapter 10 slope stability analysis nysdot geotechnical page 106 january 21, 2014 design manual 10. Step 3 analyze the stability of the slope if a groundwater phreatic surface is specified in the slope. How do friction and cohesion work together to stabilize slopes. Example of stability, erosion and development setback components n. A common problem encountered in engineering soil mechanics is the stability of soil slopes in frictional materials. In this example, three slope conditions are analyzed.
Rear property line setback 21m identified slope hazard area front lot line rear lot line top of bank stability component 16m erosion component 5m development setback component open. Analyzing slope stability by the limit equilibrium method, a. Potential failure surface parallel to the ground surface assumes gravity is the primary factor. Recall modes of slope failureexplain effects of water on slope stability discuss slope stability circular and block. Ru bbar and shansep soil strength geoslope international. The term landslide refers to a situation of instability affecting natural slopes and involving large. Where this has been done, the peat failure is usually treated as a translational planar slide and a simple infinite slope analysis is used to back calculate strength parameters of the slope at the time of failure hendrick, 1990. The graphics and the pointandclick data input are also very good and makes the program very easy to use. Swedish circle method, stability of slope, mumbai university. Swedish circle method, mumbai university solved example. Learning outcomes gat the end of this session, the participant will be able to. It also highlights some of the differences in approach to that adopted by the limit equilibrium method of slices. Spencer analysis method, homogenous material using the mohr coulomb soil model, a dry slope with no porewater pressure, two sloping anchors, and the entry and exit slip surface option. This was applied in the model by selecting all the boundary lines between the mudstone and weathered mudstone unshow the water table, to facilitate.
The software in general is very good and ties in well with the way we do things here. The slope stability can be analyse nowadays by using a computer program. 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. Chapter 4 slope stability universiti teknologi malaysia. Most critical circle corresponding to critical vertical crack depth based on shortterm stability calculations for example problem b. Application note slope stability analysis worked example. Pdf slope stability analysis using modified felleniuss and.
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