Erosion control is intended to provide surface slope stability to protect the face of the slope and to strengthen portions of the slope below. Hill slope stability analysis using two and three dimensions analysis. Evaluation of minimum factor of safety in slope stability. The user interface and analysis options are almost identical to the generalised slope analys is module except for the ability to define a slip surface of any general shape. The most critical section ii was selected for this study. In this study, a finite element fe based stability analysis is adopted to assess the failure of an existing naturally stable stratified hillslope located in. Define the following a angle of repose, b sensitive soils, c hydrocompacting clays, d groundwater, e quick clays. Slope stability best slope stability analysis software. 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 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. Prior to receiving the assignment students have developed an understanding of hillslope processes and slope stability through lecture, class activities.
Geotechnical approaches for slope stabilization in. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. Slope stability policy and procedure for pipeline design, construction and right of way maintenance. Landslides are common in the mountainous terrain of virginia due to the presence of steep slopes and. Detailed pieziometric data at multiple locations and depths within and below the slope will likely be needed. Griffiths abstract a footing on the crest of a slope may be considered as either a slope stability or a bearing capacity problem. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. The effect of water on cut and fill slope stability is briefly discussed below. To assess the stability of slopes under shortterm often during construction and longterm conditions. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. Hillslope stability and land use agu publications wiley. This analysis of soil strength variations in hillslopes is expected to describe the evolution of slope stability without imposing a specific failure.
Pdf stability assessment of a hill slopean analytical and. Paper open access modelling the stability of the aleksotas. The system provides a means of fullyvegetating slope surfaces that otherwise could not support sustainable. Students consider the balance of forces on a hillslope using the factor of safety by calculating shear stress and shear strength for an example hillslope and formulating an expression for the factor of safety in an excel. Slope stability assessment using trigger parameters and sinmap. With the exception of the pile bearing capacity module, all modules can perform deterministic analyses as well as a probabilistic analyses. Among these uncoupled methods, the most common treatment of the slopestability subproblem is through a limit equilibrium approach.
Slope stability is an ageold issue of soil and rock mechanics. How do friction and cohesion work together to stabilize slopes. Methodology of slope stability analysis it is a method to expresses the relationship between resisting forces and driving forces driving forces forces which move earth materials downslope. Evaluation of minimum factor of safety in slope stability analysis zuyu chen and changming shao institute of water consetvanc and hydroelectric power research, p. In recognition of his years of guidance and support as a mentor and friend to geotechnical specialists in the northwest, we dedicate these volumes, a summary of what we have. Slope stability analysis was performed in terms of a total stress analysis.
Symbol parameter dimensions f factor of safety against sliding along sheet joint calculated. 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. Various types of slope failure have affected most parts of slopes and road sections in an around sonapur area along nh44 within jaintia hills. With a probabilistic analysis you can take into account variations in material. Designing a stable slope includes field investigation, laboratory investigation, and construction control. Chapter 10 slope stability analysis nysdot geotechnical page 106 january 21, 2014 design manual 10. Although vetiver alone cannot stabilize a hill slope but can protect the slopes from rain cut erosion which leads to failure. The prokon geotechnical analysis suite comprises a number of modules for analysis stability and determining capacity. An assessment of hill slope stability using the factor of. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes.
The stability of slopes may be evaluated by comparison of the forces resisting failure with those tending to cause rupture along the assumed slip surface. What kinds of rock structures can reduce the stability of slopes. In this homework assignment students are asked to consider the balance of forces on a hill slope using the factor of safety. Hillslope stability and landslide hazarda case study from.
This case history, together with the laboratory saturated and unsaturated strength test results and field suction measurements, demonstrates the dramatic effect of negative porewater pressures on nearsurface slope stability. 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. The charts presented here are based on the kinematic approach of limit analysis that leads to a strict lower bound on. Slope stability analysis consists of determining and comparing the shear stress developed along the potential rupture surface with the shear strength of the soil. Slope stability analysis of soil slopes using the nonvertical slice method proposed by sarma noncircular slip. Slope stability verification manual deep excavation llc page 3 a. You can also include faults and discontinuity planes in. The deformed, weathered and fragile rocks of the lesser himalaya are often vulnerable under natural or anthropogenic influences.
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. What is the factor of safety and how does it apply to slope stability. Overstressing of a slope or reduction in shear strength of the soil may cause rapid or progressive displacements. Slope stability is an extremely important consideration in the design and construction of embankments, earth dams, trenches and various other geotechnical structures. There may be sections along hill roads with the cross slope less than 25%, especially when the road follows a river route. We analyze the physical principles that underlie both the most frequently used computational methods and some less common but accurate methods.
In recognition of his years of guidance and support as a mentor and friend to geotechnical specialists in the northwest. Downslope component of weight of material including vegetation, fill material, or. Geomorphological control on variably saturated hillslope hydrology. While computational tools have made most graphical methods and charts obsolete, stability charts for slopes are still routinely used in practice. Soil moisture storage and hillslope stability semantic scholar. This paper aims an overview on various methods of slope stability on. Continuum deformation and stability analyses of a steep. Slope stability and erosion control slope stability can be generally described as the inherent structural integrity of a slope to resist failure. 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. Pdf stability of a hill slope using le and fe analyses.
Safety factor sf calculation for a slope a without tension crack b with a waterfilled tension crack. Slope stability verification manual deep excavation llc page 11 e. 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. Deterministic and probabilistic analyses are possible. The presto geoweb slope and shoreline protection system is an economical solution to challenging slopesurface stability problems while meeting a wide range of performance and aesthetic requirements. Bali island is characterized by generally steep rolling hills in the. Attention has to be paid to geology, surface drainage, groundwater, and the. Slope instability is very common phenomenon, especially in tectonically active hills of the lesser himalaya. Various methods are available for slope stability analysis. Attention has to be paid to geology, surface drainage, groundwater, and the shear strength of soils in assessing slope stability.
Cdotdtdr200210 sponsored by the colorado department of transportation in cooperation with the u. 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. Slopew can effectively analyze both simple and complex problems for a variety of slip surface shapes, porewater pressure conditions, soil properties, and loading conditions. Slope stability assessment is a fundamental step in evaluating landslide hazard and for the safe design of structures and infrastructures. Evaluation of slope stabilization methods us 40 berthoud pass by michael banovich william skip outcalt report no. The slope stability assessment in this report is based on subsurface conditions in the boreholes, the observations during our site visits, and the slope profiles provided by the client. Box 366, beijing, peoples republic of chitla received september 1, 1987 accepted april 11, 1988. In what ways does water added to a slope affect its stability. An overview on methods for slope stability analysis. Traditional slope stability analysis delivers the safety factor with respect to. Introduction this document contains a series of verification slope stability problems that have been analyzed.
Tagasoft geotechnical software slope stability analysis. In this study, a finite element fe based stability analysis is adopted to assess the failure of an existing naturally stable stratified hill slope located in the umrangso region at dima hasao district of assam, india. The aim of the research was to perform gross slope stability analysis for the aleksotas hill the of original natural slope and excavated slope with constructed subsurface drainage. 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. Hillslope stability and landslide hazarda case study from longdendale. Box 366, beijing, peoples republic of chitla received september 1, 1987 accepted april 11, 1988 this paper explores the feasibility of using optimization methods to search for. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. Soil samples from a hill slope sections were collected viz. There were several cases of slope failure along highway sections in uttarakhand himalaya. Excessive rainfall, cutting of hill slopes, deforestation, steep slope and. Numerical investigation of hill slope instability due to.
To assess the possibility of landslides involving natural or existing engineered. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. An assessment of hill slope stability using the factor of safety. Effect of soil suction on slope stability at notch hill. Stability analyses of the slopes were carried out using the computer program slide 6 with the bishops method of analysis. Slope stability united states army corps of engineers. Slope stability analysis slope stability analysis stabilizing a slope using antislide piles stabilizing a slope using antislide piles inputting geometry by importing data from a dxf file inputting geometry by importing data from a dxf file using standards and analysis settings using standards and analysis settings importing data in txt format. Detailed pieziometric data at multiple locations and depths within and. A hill road may be defined as the one which passes through a terrain with a cross slope of 25% or more.
How does the slope angle play a role in slope stability. Slope stability is the best slope stability analysis software suite around providing complete supported slope analysis. Predict hillslope stability using the factor of safety fs. 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. Slope stability analysis slopew is the leading slope stability software for soil and rock slopes. A near vertical slope, more than 80 to the horizontal talus scree debris a slope with a constant angle, and is formed of eroded material from crest and freeface knickpoint the change in gradient at the base of the scree slope pediment a lowangle concave slope characteristics of slopes crest edge of the hill convex. Pdf landslide is a very common natural disaster in bangladesh.
Slope failures depend on the soil type, soil stratification, groundwater, seepage and slope geometry. Department of transportation federal highway administration july 2002 colorado department of transportation research branch. Mar 29, 2017 slope instability is very common phenomenon, especially in tectonically active hills of the lesser himalaya. The quiz will be based on chapter 8 of this fhwa publication. Hillslope hydrology and stability assets cambridge university. Draw freebody diagram of forces acting on this slice and then formulate equilibrium equations. Even then these sections are also referred to as hill roads. Failure can occur as slides, cracks and slope movement. 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. They are certainly major factors in cut slope stability and in the stability of fill slopes involving both internal and external slope failures. The study was carried out along a highway section of nh109. Third, finding the correct method of stability analysis solves only part of the design problem. Shalstab modeling approaches for slope stability analysis at shallow.
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