The effect of water on cut and fill slope stability is briefly discussed below. Stability of natural slopes the possible instability of natural slopes is a major geologic hazard in many regions of the world. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. Hence, these analyses are not typical limit state problems where the magnitude of the load is sought, causing the structure to fail. During blasting the explosion gases will force their way out of the rock mass via the karstic discontinuities rather than by breaking intact rock or by following discontinuities to the next. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. 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. For an additional 9 years he was a principal advisor to. They are certainly major factors in cut slope stability and in the stability of fill slopes involving both internal and external slope failures.
While reasonable efforts have been made to assure the accuracy of this publication, in no event will the authors, the editors, or the usda forest service be liable for direct, indirect, incidental, or. The aim of this study was to demonstrate that a slope needed to be analyzed in many different directions in order to assess its stability conclusively, rather than using just one crosssectional profile to represent the entire slope. Despite the advances that have been made, evaluating the stability of slopes remains a challenge 4, 5, 6, and 7. Slope stability analyses in practice mostly rely on limit equilibrium le procedures rather than finite element fe or finite difference fd procedures. The limit equilibrium method is the most common approach for analyzing slope stability in both two and three dimensions. Fhwa nhi06088 6 slope stability soils and foundations volume i 6 3 december 2006 6. 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. Presently, most slope stability methods are twodimensional 2d which assumes the failure surface is infinitely wide and therefore three dimensional 3d shear resistanceforces are. Slope stability hazard assessment and mitigation 167 presence of these filled sinkholes during excavation, have an adverse effect on the slope stability. In this study slope w 2007has been applied separately and together with seepw, sigmaw, based on finite elements mesh were coupled with slope stability analysis to determine the factor of safety, this is the key issue on slope monitoring gradually drawdown for the water level and longterm stability. The term landslide refers to a situation of instability affecting natural slopes and involving large volumes of soil. Probabilistic slope stability analysis by finite elements.
Downloading the slope64 program the source code for slope64 is written in fortran 2003, but users are provided with the executable file slope64. These studies confirmed that a large excavation on the steep north bank was required to remove unstable materials and flatten the slope for longterm. Limit analysis in slope stability most engineering analyses of slope stability seek the factor of safety, which is a traditional measure of the safety margin. Detailed pieziometric data at multiple locations and depths within and. Using a unified approach to address a medley of engineering and construction problems, slope stability analysis and stabilization. New scientific research and practical advice in the field of slope stability and. Analysis of design choices for a slope stability scenario in the humid. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. An example involving the use of this method will be discussed later. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. To assess the possibility of landslides involving natural or existing engineered slopes. This paper presents an analysis of soil slope stability using a terrestrial laser scanner, particle swarm optimization, and the force equilibrium method.
In this paper we investigate the probability of failure of a cohesive slope using both simple and more advanced probabilistic analysis tools. Slope stability guidelines for development applications documents. Slope stability lesson 06 topic 1 stability analysis of slopes. 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. Gravity the main force responsible for mass movement is gravity. Global stability with relict slip surface in this scenario, the presence of the relict slip surface was assumed. Limit analysis and stability charts for 3d slope failures. Includes recommendations for analysis, design practice, design charts, tables, and more. Slope stability hazard assessment and mitigation methodology. Pdf stability analysis of slopes reinforced with piles. Slope stability is an intuitive program for the analyses of all types of slopes and retaining walls.
Start a new file and define the slope cross section. How do friction and cohesion work together to stabilize slopes. The effect of vegetation on slope stability of shallow pyroclastic soil. Lisa and xstabl have become standard analysis tools for resource planning level and sitespecific slope stability assessments, respectively, on national forests in the westem united states. The term slope means a portion of the natural slope whose original profile has been modified by artificial interventions relevant with respect to stability. A major revision of the comprehensive textreference written by worldleading geotechnical engineers who share almost 100 years of combined experience, slope stability and stabilization, second edition assembles the background information, theory, analytical methods, design and construction approaches, and practical examples necessary to carry out a complete slope stability project. Slopes are required in the construction of highway and railway embankments, earth dams, levees, canals etc. The degree of stability of a slope may be expressed through the factor of safety f, which is the ratio between a soil resistance measure and the associated applied load. Set up a slope stability problem in slope w based on the seepw finite element mesh and computed porewater pressure. Slope stability using the bishop simplified method.
Attention has to be paid to geology, surface drainage, groundwater, and the shear strength of soils in assessing slope stability. An introduction to slope stability and protection j. Attention has to be paid to geology, surface drainage, groundwater, and the. 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. Slope w is a twodimensional limit equilibrium stability analysis software program that permits slope stability calculation using various limit equilibrium methods. Slope stability analysis consists of determining and comparing the shear stress developed along the potential rupture surface with the shear strength of the soil. The solution to a stability problem must be dependent.
Griffiths and marquez 2007 compare the results of 2d slope and 3d slope analyses. 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. It is concerned with 1 the characteristics and critical aspects of various types of slope stability problems, 2 geologic studies and site investigation procedures, 3 methods of designing slopes, including field observations and experience, slope stability charts, and. Geoslope international ltd, calgary, alberta, canada. Slope stability analysis by the limit equilibrium method.
Slope stability analysis by the limit equilibrium method books. Limit analysis and stability charts for 3d slope failures radoslaw l. Slope stability during interim fill phase development. Paul guyer is a registered mechanical engineer, civil engineer, fire protection engineer and architect with over 35 years experience in the design of buildings and related infrastructure. The effect of water level on the stability of slopes. Geometric effect 35 yses to backcalculate shear strengths, the results from back calculation will be overestimated. A major revision of the comprehensive textreference.
The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. This was applied in the model by selecting all the boundary lines between the mudstone and weathered mudstone unshow the water table, to facilitate. Application note slope stability analysis worked example. Lisa and xstabl have become standard analysis tools for resource planning level and sitespecific slope stability assessments, respectively, on. Slope is an exposed ground surface that stands at an angle with the horizontal. For dry soil, one generally assumes that the soil shears when the shear stress is equal to the shear strength of the soil. Rock slope stability analysis utilization of advanced numerical techniques dr. Slope stability reference guide for national forests in the united states volume i11 august 1994.
Written by worldleading geotechnical engineers who share almost 100 years of combined experience, slope stability and stabilization, second edition assembles the background information, theory, analytical methods, design and construction approaches, and practical examples necessary to carry out a complete slope stability project. This work includes the removal of approximately nine million cubic metres of material. Fundamentals of slope design keynote address at slope. Slopes in mountainous regions require cohesion 8 undrained short term slope failure in clay. Survey usgs scoops3d slope stability model 20, which employs the. Probabilistic slope stability analysis by finite elements d. Stability analysis lisa, stability analysis for road access sara, the level i1 program, and xstabl the level 111 program. Seepw generated porewater pressures in slopew stability.
All other walls require an excavation which remains open while the wall is erected. Slope stability and stabilization methods, 2nd edition wiley. Taylor 1937 conceived the idea of analyzing the stability of a large number of slopes through a wide range of slope angles and. It also highlights some of the differences in approach to that adopted by the limit equilibrium method of slices. New slope stability considerations for deep open pit mines. 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. To analyze landslides and to understand failure mechanisms and the influence of environmental factors. To assess the stability of slopes under shortterm often during construction and longterm conditions. Let us first consider the stability of a slope underlain by dry soil, so that porewater pressures are zero. Application note slope stability analysis worked example 4. Slope stability, triggering events, mass movement hazards. Slope stability analysis by finite elements article pdf available in geotechnique 517. Evaluation of slope stability is one of the daytoday practices of geotechnical engineers.
They are certainly major factors in cut slope stability and in. Constructed in the slope from the top down in sections to provide continuous retention of the slope during construction. Next to gravity, water is the most important factor in slope stability. 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 spencer 1967 method was selected for all slope stability analyses because it is. 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. Slope stability evaluation for the new railway embankment. The stability analysis is of a homogeneous slope subjected to a horizontal acceleration factor. 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. On a flat surface the force of gravity acts downward. The north bank slope stabilization activities are expected to take about five years to complete. Parametric studies of slope stability analyses using threedimensional finite element technique. As part of the ongoing slope stabilization work, bc hydro and its contractors are aware of the potential for slope movements.
Slope stability verification manual deep excavation llc page 11 e. North bank slope stabilization prior to the start of site c construction, extensive geotechnical studies were undertaken throughout the project area, including an analysis of slope stability. Slope stability when the final fill elevations are attained and 3. Slope stability assessment is particularly challenging in developing countries. The setback gradient line measured from the toe of the slope, or channel assuming the location of the toe remains fixed with time. Soils and foundations testing experience theory lesson 06 chapter 6 slope stability. Gravity is the force that acts everywhere on the earths surface, pulling everything in a direction toward the center of the earth. The files needed to run the slope program with one of the examples are as follows. Slope stability, triggering events, mass movement hazards factors that influence slope stability gravity the main force responsible for mass movement is gravity. Slope stability during excavation prior to waste placement.
Rock slope stability analysis utilization of advanced. 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. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. Slope stability verification manual deep excavation llc page 18. This report presents the results of the slope stability analyses for the permitlevel marana regional landfill design. He applies probability techniques in geotechnical engineering to slope failure analysis or strip stability investigations and slope design for coal strip mines and open pit mines internationally.
Erik eberhardt university of british columbia geological engineeringearth and ocean sciences, ubc, 6339 stores rd. Chapter 10 slope stability analysis nysdot geotechnical page 106 january 21, 2014 design manual 10. Fundamentals and methods presents basic principles for the safe design of constructed or natural earth slopes. The term landslide refers to a situation of instability affecting natural slopes and involving large. Apr 12, 2017 slope stability analysis consists of determining and comparing the shear stress developed along the potential rupture surface with the shear strength of the soil. The shear strength reduction method is now widely used in open pit slope stability studies because it includes all the benefits of limit equilibrium analyses and it allows the user to study slope displacements that are critical in the evaluation of open pit stability. In this study slope w 2007has been applied separately and together with seepw, sigmaw, based on finite elements mesh were coupled with slope stability analysis to determine the factor of safety, this is the key issue on slope monitoring gradually drawdown for the water level and longterm stability study 8.
The kinematic approach of limit analysis is explored in threedimensional 3d stability analysis of slopes. Stability analysis of slopes reinforced with piles when the safety factor for a slope is considered to be inadequate, slope stability may be improved installing a retaining structure such as a row. The results of the handmade calculations are compared with the results from the geo5 slope stability program. Slope stability, water level, sliding surface, safety factor introduction the rock slope stability is one of the most important problems in large construction projects and factors that cause instability of slopes lead to rock fall, soil and debris and finally destroying the balance of mass in slope. How does the slope angle play a role in slope stability. Retention capacity is high and they have been used to support. Nowadays, different approaches are available to evaluate the stability of a particular slope 1, 2, and 3. The aims of slope stability analyses are to understand the development and form of natural slopes and the processes responsible for different natural features.
463 137 1407 849 730 662 41 124 819 786 1630 1522 1007 51 388 1542 1638 240 1327 1640 1168 53 808 685 1445 1215 337 1522 87 405 1076 1105 1017 142 139 238 47 395 632 47 627