Stability of slopes in open excavation in different soil condition along with the factors that control slope stability in open excavation are discussed. 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. Pdf rock slope stability assessment by using kinematic. Slope stability is the process of calculating and assessing how much stress a particular slope can manage before failing. Rock slope stability of the vmt prince william sound. Slope stability, triggering events, mass movement hazards. The stability of the slope depends on the slope geometry, strength of slope forming materials, rock type, discontinuity characteristics, weathering rate, and groundwater condition. They are certainly major factors in cut slope stability and in. Slope stability hazard assessment and mitigation methodology. Pdf slope stability analysis methods danial salajegheh. The factor of safety, f, is defined with respect to shear strength as, f. One of the softwares that can analyze rock slope stability in a nu.
The slope angle is usually referred to as a ratio, for example, 2. Slope stability is a major concern for geotechnical and mining engineers worldwide, and consequently, a great deal of effort at rocscience is dedicated to slope stability analysis software. Rock slope stability analysis lec 1 linkedin slideshare. In hard rock, blasting of the slope will likely be required. The term landslide refers to a situation of instability affecting natural slopes and involving large. 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 graphics and the pointandclick data input are also very good and makes the program very easy to use. Rock slope stability analysis utilization of advanced. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. 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. How does the slope angle play a role in slope stability. The design engineer and the regulator must be familiar with the concepts to choose the best design at the lowest cost.
Dykes and sills are yet other geological structures that can be important in rock slope engineering works. Evaluation of slope stability is one of the daytoday practices of geotechnical engineers. The software in general is very good and ties in well with the way we do things here. Introduction lopes may be natural or manmade or earth dam.
The slope stability analysis was performed using the simplified bishop method of slices to discretize the soil mass to establish the minimum factor of safety of the slope. Finally, several case studies of slope stability analysis are summarized. The probabalistic sara stability analysis for road access program is still under development. These studies confirmed that a large excavation on the steep north bank was required to remove unstable materials and flatten the slope for longterm. Most leaders dont even know the game theyre in simon sinek at live2lead 2016 duration. Rock slope stability and the design of the appropriate slope angle is extremely important for surface mining in these difficult economic times. Slope stability lesson 06 topic 1 stability analysis of slopes.
Soils and foundations testing experience theory lesson 06 chapter 6 slope stability. How do friction and cohesion work together to stabilize slopes. This book focuses on rock slope stability, with sections on geological data collection. Rock slope stability analysis utilization of advanced numerical techniques dr. 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. The moment is then calculated about the center of the trial surface. Discovery ce employ civil engineers and engineering geologists with a wealth of expertise in all aspects of geotechnics including slope stability analysis and assessment. The most serious disorders which can occur in slopes are 1 the sliding of blocks along the discontinuing surfaces which exist at the opening of trenches and 2 rock falls or sliding of blocks resulting from the rapid change in the mechanical characteristics of the rock bench which supports them. Today, there are several methods for slope stability analysis, each has its own advantages and disadvantages. The three simplest structurally controlled failure mechanisms are also the most commonly assessed in rock masses. Slope stability analysis by the limit equilibrium method. Rock slope stability download ebook pdf, epub, tuebl, mobi. It describes the basic rock slope failure modes and methods of analysisboth kinematic and kinetic techniques.
The anchors used for slope stabilization are typically 6 m 20 ft in length, 20 mm to 50 mm 58 to 2 in in diameter and made of highstrength steel bars can be coupled to increase the length up to 30 m or 100 ft, but the total length of a stabilization bar is generally limited to 12 m or 40. Application note slope stability analysis worked example 4. 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. This program is used to perform slope stability analysis embankments, earth cuts, anchored retaining structures, mse walls, etc. Small rockfalls, which may involve handsized rocks weighing only a few kilograms, can cause fatal injuries to workers away from the. Field reconnaissance and a detailed fracture survey of the rock slopes were conducted by dr.
Department of transportation report number cdotdtdr966, evaluation of slope stabilization methods us 40 berthoud pass price 1996. The purpose of the following section is to apply the kinematic approach of limit analysis described in the previous section to assess the stability of a rock slope see fig. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. Principle of slope stability analysis sliding will occur if the shear stress developed exceeds the corresponding shear resistance of the soil. 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 primary purpose of this project was to evaluate the stability of rock slopes of the vmt during potential earthquake conditions.
Numerical analyses methods are the most common ones that are used for rock and soil slope analyses. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. While less than 1% of reported accidents are associated with slope stability problems, slope failures were responsible for about 15% of all u. The design of too flat of a highwall angle means considerable additional mining costs. A geomechanical assessment is underway to evaluate the stability of the walls for expansion over the next 15 years. For an additional 9 years he was a principal advisor to. What are the factors that influence slope stability. Slope angle or simply slope is the angle of inclination of a slope to the horizontal. Keywords angle of internal friction, cohesion, factor of safety, slope stability. Rock slope stability analyses are routinely performed and directed towards assessing the safe and functional design of excavated slopes e.
Every slope has forces acting on it that tend to disturb its stability. 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. Slope stability hazard assessment and mitigation 167 presence of these filled sinkholes during excavation, have an adverse effect on the slope stability. Comparative study of slope stability analysis using. Time during which the excavation is required to be open.
In this paper a numerical analysis of slope stability problems in blocky rock is presented with emphasis given to the various possible failure modes block sliding andor block tilting. Slope stability verification manual deep excavation llc page 11 e. Global stability with relict slip surface in this scenario, the presence of the relict slip surface was assumed. Of the software which is currently available from rocscience, half of all programs are either specifically dedicated to slope stability analysis ie. Slope stability, triggering events, mass movement hazards factors that influence slope stability gravity the main force responsible for mass movement is gravity. Chapters include geotechnical and geomechanical analysis techniques, hydrology, rock slope stabilization techniques, and geotechnical instrumentation and monitoring. Computations can be performed for homogeneous and inhomogeneous slopes using both circular and noncircular slip potential sliding surfaces. Stability of slopes for excavations in different soil types. This was applied in the model by selecting all the boundary lines between the mudstone and weathered mudstone unshow the water table, to facilitate. Retention capacity is high and they have been used to support. The method satisfies vertical force equilibrium for each slice. Engineering geology of rock slopes in highway construction. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. Slope stability reference guide for national forests forest sewice engineering staff in the united states washington, dc em71 701 3 volume i11 august 1994 coordinators.
Application note slope stability analysis worked example. A comprehensive guide for mining and construction engineers responsible for rock slope stability. An introduction to slope stability and protection j. 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. The general aim of this research is to access the relation in terms of slope stability or factor of safety between new slope design dip slope mining and the orientation of the pit slope curvature. Rock slope engineering civil engineering i am menglim. Softer rock slopes may be laid back to match existing soil slopes and covered with topsoil and vegetation. The term landslide refers to the movement of a mass of rock, debris or earth soil down a slope ags, 2007a. Considering the importance of slope stability to their work, its beneficial for civil engineers to understand how to. Slope stability analysis in that paper they conclude a methodology of slope stability analysis and provide an insight into the basic of constant affected by change in relationship for shearing stress and resistance.
Slope stability evaluation for the new railway embankment. Stability analysis of rock slopes subjected to seepage. Stability analysis of a rock slope in himalayas article pdf available in geomechanics and engineering 22 june 2010 with 2,238 reads how we measure reads. The slope stability can be analyse nowadays by using a computer program. Innovative solutions for slope stability reinforcement and characterization. In civil engineering, projects include transportation systems such as highways and railways, dams for power production and water supply, and industrial and urban development. It also highlights some of the differences in approach to that adopted by the limit equilibrium method of slices. In this case, failure is assumes at a certain plane w sin. Site constraints often result in new developments being constructed close to the crest of marginally stable slopes such as this development at cemex cement works in rugby. Pdf on jan 1, 2011, alavi nezhad khalil s v abad and others published rock slope stability assessment by using kinematic analysis and slope mass rating at bandar seri alam, johor find, read. Slope stability analysis must take into account a variety of factors relating to topography, geology and material properties, often associated to whether the slope was naturally formed or engineered. Ii abstract soil slope instability concerning highway infrastructure is an ongoing problem in iowa, as slope failures endanger public safety and continue to result in costly repair work. This paper presents an analysis of soil slope stability using a terrestrial laser scanner, particle swarm optimization, and the force equilibrium method.
The slip surface is considered as circular bishop, felleniuspetterson, janbu, morgensternprice or spencer methods or polygonal sarma, janbu, morgensternprice or spencer methods. 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. On a flat surface the force of gravity acts downward. Erosion, driven by gravity, is the inevitable response to that uplift, and various types of erosion, including mass wasting, have created slopes in the uplifted regions. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes.
Erik eberhardt university of british columbia geological engineeringearth and ocean sciences, ubc, 6339 stores rd. Nowadays, different approaches are available to evaluate the stability of a particular slope 1, 2, and 3. Innovative solutions for slope stability reinforcement and. Despite the advances that have been made, evaluating the stability of slopes remains a challenge 4, 5, 6, and 7.
Our programs include software for 2d and 3d soil and rock slope stability, limit equilibrium and finite element analysis, and 2d and 3d. The main focus of this report is on slope stability. The software performs limit equilibrium slope stability calculations for a factor of safety. Numerous examples, drawings, and photos enhance the text. A slope stability problem in hong kong 7 the symbols and dimensions used in these models are as follows. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. The slope stability analysis has been prepared in accordance with the proposal dated june 2,2000. In contrast, the terms landslide or landslip, which do constitute slope failure, are often used interchangeably. Slopes in mountainous regions require cohesion 8 undrained short term slope failure in clay. Fundamentals and methods presents basic principles for the safe design of constructed or natural earth slopes. Attachment a contains information regarding the slope stability analysis and includes five exhibits of supporting data. The spencer method of slope stability analysis was used to assess the stability of the wall using the same rock mass parameters as in the udec analysis.
The extent of the root zone is defined by thedepth of root zone, h r. The limit equilibrium method is the most common approach for analyzing slope stability in both two and three dimensions. As a matter of fact, the latter ones appear as a component of the external. Chapter 10 slope stability analysis nysdot geotechnical page 106 january 21, 2014 design manual 10. 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. As part of the slope design program and slope optimisation for the next pushback, the past and present performance of the pit slopes were evaluated to assess the potential behaviour of future pit expansion. Pdf stability analysis of a rock slope in himalayas. All other walls require an excavation which remains open while the wall is erected. Slope stability does not necessarily constitute slope failure. Fhwa nhi06088 6 slope stability soils and foundations volume i 6 3 december 2006 6. Taylor 1937 conceived the idea of analyzing the stability of a large number of slopes through a wide range of slope angles and.
Design of overall slope angle and analysis of rock slope. This engineer manual em provides guidance for analyzing the static stability of slopes of earth and rock fill dams, slopes of other types of embankments, excavated slopes, and natural slopes in soil and soft rock. As a major focus area for research and development at rocscience, our suite of slope stability analysis software is highly developed and can meet the demands of even the most advanced geotechnical projects. Evaluating techniques for monitoring rock falls and slope. Slope stability best slope stability analysis software. Chapter 10 slope stability analysis nysdot geotechnical page 1010 january 21, 2014 design manual 10. Pdf rock slope assessment using kinematic and numerical.
Attachment b contains information regarding the erosion analysis and includes six exhibits of supporting data. Rock slope stability is also an important consideration in the design of transportation corridors, such as roads, highways, and rail lines. The term slope means a portion of the natural slope whose original profile has been modified by artificial interventions relevant with respect to stability. Parametric studies are conducted and the results are used to develop a set of stability charts that can be used to assess the contribution of root reinforcement on slope stability. The results of the analysis with critical failure surfaces through the rock mass show that the wall is stable and estimates the factor of safety to be 2. Slope stability, slope stability analysis deep excavation. Slope stability in strong rock 25 mpa based on classification from hungr et al. Constructed in the slope from the top down in sections to provide continuous retention of the slope during construction. Allowable degree of risk of slipping which is determined based on the existing structures and new constructed buildings around the. An overview on methods for slope stability analysis. Low rock cuts rock slopes or soil slopes by the designer. 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. Gravity is the force that acts everywhere on the earths surface, pulling everything in a direction toward the center of the earth. Chapter 4 slope stability home people at universiti.
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