Trevor orr trinity college dublin convenor tc250sc7eg3. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. The focus in this chapter is on soil slopes and mechanisms involving shear failure within the soil mass. To assess the stability of slopes under shortterm often during construction and longterm conditions. It was found that the distribution, relative position, and shape of rock have significant effect on slope.
Step 1 create the slope model grid, set boundary conditions, assign material model and specify properties. 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. To assess the possibility of landslides involving natural or existing engineered. Soil mechanics slope stability most trail construction should take place on slopes, not flat ground, and should proceed with the best practices of road construction engineering, yet depending on the user groups it wont have quite the same load requirements or factors of safety required for roads local requirements or regulations pending. Determination of the critical slip surface in slope. Allowable degree of risk of slipping which is determined based on the existing structures and new constructed buildings around the. Soilrock slope stability analysis by considering the. The definitive guide to the critical issue of slope stability and safety. The analyses of slope stability are based on simplifying assumptions, and the design of a stable slope relies heavily on experience and careful site investigation. The stability of slopes can be assessed by a factor of safety, which is usually determined by a limit equilibrium method. Slope failure is the movement of mass on slope falls, slides, flows landslide. Soil strength and slope stability, 2nd edition wiley.
This course is designed to supplement the theory and practice of soil mechanics that you learn in courses taught in civil engineering. Third, finding the correct method of stability analysis solves only part of the design problem. Methods are also presented for checking the results of complex analyses and for presenting results of slope stability analyses. Discuss slope stability circular and block analyses. How do friction and cohesion work together to stabilize slopes. Soil strength and slope stability fills the gap in industry literature by providing practical information on the subject without including extraneous theory that may distract from the. When the component of gravity is large enough, slope failure can occur, i. Different slope stability analysis software programs were used and compared, and a formula was presented to calculate the length of failure arc by knowing the soil strength parameters. The methods described are applicable to landslides in. An overview on methods for slope stability analysis. The graphics and the pointandclick data input are also very good and makes the program very easy to use. Detailed pieziometric data at multiple locations and depths within and below the slope will likely be needed.
Pdf the slope failure is a dangerous phenomenon for natural or manmade slopes. Examples of slope failure 5 causes of slope failure 14 summary 17 chapter 3 soil mechanics principles 19 drained and undrained conditions 19 total and effective stresses 21 drained and undrained shear strengths 22 basic requirements for slope stability analyses 26 chapter 4 stability conditions for analyses 31 endofconstruction stability 31. Side slope stability analysis the primary aim of slope analysis is to compare the stability of selected 1. Focus is on the principles of limit equilibrium analysis and the appropriate use of computer programs. Michael duncan soil slope stability analysis analyses of slopes can be divided into two cat egories.
Designing a stable slope includes field investigation, laboratory investigation, and construction control. Determination of the critical slip surface in slope stability. Guidance on the collection, handling and storage of soil for the assessment o soil qualitysampling. Stability problems most often occur when the embankment is to be built over soft soils such as low strength clays, silts, or peats. Stability analysis is performed using slopew geostudio 2007. The failure plane here does not have a specific shape. The slope stability analysis is crucial in engineering practice to ensure the stability of structures and prevent loss of human life and money. The purpose of this manual is to provide engineers and geologists involved in highway design and construction with a common understanding and approach to slope stability analysis for highway projects. Although these methods define movements and stresses throughout the slope, they do not provide a direct measure of stability, such as the factor of safety calculated by limit equilibrium analyses. Part ii1 soil composition, index properties and soil classification pdf 1. Pdf soil strength and slope stability semantic scholar. Pdf stability analysis of slope with different soil types and its.
Slope stability is one of the most sophisticated and challenging problems for all mining and geotechnical engineeringdisciplines. Vegetation modifies the moisture content of the soil, influencing soil strength, and the presence of roots in the soil increases soil strength and, therefore, its stability. Stabilization techniques used in the present study are berming, soil nailing and. Department of transportation federal highway administration july 2002 colorado department of transportation research branch. Modeling the unsaturated soil zone in slope stability. Cdotdtdr200210 sponsored by the colorado department of transportation in cooperation with the u. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. The probabalistic sara stability analysis for road access program is still under development. In this study, a slope stability analysis method considering the nonuniform characteristics of rocks was proposed.
Failures translational type failure of slope along weak zone of soil. The software in general is very good and ties in well with the way we do things here. Slope stability and slope engineering geotechnical engineering. Evaluate the in situ soil properties and either reuse the material or use common borrow if native material has poor properties. Fhwa nhi06088 6 slope stability soils and foundations volume i 6 3 december 2006 6. Step 2 analyze the stability of the slope for different strength properties. The mass of soil or rock bounded by the failure surface should normally be treated as a rigid body or several rigid bodies moving simultaneously stability may be checked by limit analysis or by the finite element method 9 20. Pdf importance of slope stability problem is the reason why so many alternate methods have been developed for evaluating the safety of a slope. Soil rock slopes are widely distributed around the world, while the commonly adopted method by simplifying it as a uniform media tends to be excessively conservative. Stability analysis of soil slope, kaliyasaur village anand singh1, pankaj goswami. Mar 21, 2016 the aims of slope stability analyses are to understand the development and form of natural slopes and the processes responsible for different natural features. Soil strength and slope stability kindle edition by duncan, j.
Soil strength and slope stability deere and patton1971,slope stability in residual soil length slope factors for applying the revised universal soil loss soil qualitysampling. Such failures can be assess by different numerical or limit. Using clear, concise language and practical examples, the book explains the practical aspects of geotechnical engineering as. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes. Stability of slopes in open excavation in different soil condition along with the factors that control slope stability in open excavation are discussed.
Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. It is understood possibility approaching certain level of slope stability based on experimental. The failure of a mass of soil located beneath a slope is called as slide. Step 3 analyze the stability of the slope if a groundwater phreatic surface is specified in the slope. Slope stability united states army corps of engineers.
The aims of slope stability analyses are to understand the development and form of natural slopes and the processes responsible for different natural features. This chapter provides a basic outline of slope stability analysis. They are certainly major factors in cut slope stability and in. Slope stability causes of instability, analysis methods. In recent decades, substantial progress in the knowledge and practice concerning slope analysis has been made. Calculate the factor of safety f against sliding along the potential failure surface qs. Pond containment dike slope stability depends on construction materials as well as subsurface soil conditions below the embankments and ponds.
In order to evaluate the factor of safety, we need such strength parameters as cohesion and the internal friction angle. Rocksoil slope stability analysis by twophase random media and. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the. The survey discussed the plant groups relevant to slope stabilisation, the form.
Ward wilson d a center for marine geotechnical engineering, state key laboratory of ocean engineering, shanghai jiaotong university, 800 dongchuan road, shanghai, china. This broad definition encompasses many and varied applications. Sliding mass travel long distance before coming to rest. Slope stability is a critical element of geotechnical engineering, involved in virtually every civil engineering project, especially highway development. Part v1 introduction, pore pressure parameters and undrained shear. 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. Reinforced soil slopes and embankments for the purposes of this document, a reinforced slope is defined as a compacted fill embankment that incorporates the use of horizontally placed geosynthetic reinforcement to enhance the stability of the soil structure. Sayed mohamed elaraby 3 11 types of soil slope failures slip surface. Slope stability verification manual deep excavation llc page 11 e. This book describes the stateoftheart methodology for evaluating and analyzing soil strength and the design and stabilization of slopes in soil. Part v4 estimation of design s u in practice pdf 2. The definitive guide to the critical issue of slope stability and safety soil strength and slope stability, second edition presents the latest thinking and techniques in the assessment of natural and manmade slopes, and the factors that cause them to survive or crumble.
A slope is an inclined boundary surface between air and the body of an earthwork such as highways, cut or fill, railway cut or fill, earth dams, levees and river training work. Due to landslides, the himalayan region often faces geo environmental problems posing threats to, both, life and properties. Detailed pieziometric data at multiple locations and depths within and below the slope. Regrading and recompacting the slope properly will increase soil strength and slope stability. Evaluation of slope stabilization methods us 40 berthoud pass by michael banovich william skip outcalt report no. Soil bioengineering is a term that describes the use of living plant materials to build structures that provide slope support.
However, rocksoil slope stability has been rarely considered, despite the. For detailed design guidance and reference, geotechnical designers are directed to fhwanhi 05123 soil slope and embankment design. Effect of water on slope stability contd gfills on clays and siltssoil consolidates as water is squeezed out factor of safety increases with time gcuts in claysoil absorbs water when overburden pressure removed factor of safety decreases with time. Pdf slope stability analysis has to be done for the proper functioning of infrastructure in hilly areas. A slope is defined as a surface of which one end or side is. These ash landfillsponds need to be designed to prevent localized slope failures that weaken the embankment or global failure that causes the entire embankment to rupture. The analytical techniques allow comparison of various design alternatives, including effects of those alternatives on the stability of the slope and the economy of the solutions. These analyses are often completed using slope stability charts and the dsara deterministic stability analysis for road access slope stability program. The slope stability design procedures outlined in chapter 7 clearly involve a relation between available shear strength and applied shear stress within a soil mass.
Pdf back analysis method in soil slope stability behnam. Soils and foundations testing experience theory lesson 06 chapter 6 slope stability. Modeling the unsaturated soil zone in slope stability analysis 1. Slope stability of soils is one of the major problems since the ancient times. Example application 1 slope stability for a cohesive and.
It can take place in soil with high water content or in dry soils. The slope stability analysis of embankment and foundation soil was conducted using the slope w component of geostudio software geo slope. If slope stability is the potential of a slope to landslide, natural or manmade factors that provoke this movement of a mass of soil, rock or debris down a slope have to be well understood to predict or to prevent the problem. Abstract landslides are one of the important natural hazards of himalaya. Stability of slopes for excavations in different soil types. Please like and subscribe for an nguyens channel to watch the new videos. The failed soil mass can move very quickly over large distances. How does the slope angle play a role in slope stability. Sliding will occur if the shear stress developed exceeds the corresponding shear resistance of the soil. Stability modeling with slopew an engineering methodology september 2014 edition geoslope international ltd.
A slope failure adjacent to a roadway is shown in figure 16. Chapter 4 slope stability universiti teknologi malaysia. The soil parameters of this problem, the external loadings and the piezometric surface are shown in tables g. The following set of lecture notes cover every major topic discussed in class.
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