Fundamentals and methods presents basic principles for the safe design of constructed or natural earth slopes. Threedimensional slope stability problem with a surcharge load. 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. Fhwa nhi06088 6 slope stability soils and foundations volume i 6 3 december 2006 6. 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. Thus, the pseudostatic slope stability procedure is a potentially attractive design tool. To assess the stability of slopes under shortterm often during construction and longterm conditions.
In theory, the seismic coefficient values should depend on some measure of the amplitude of the inertial force i nduced in the slope by the dynamic forces generated dur ing an eart hquake. Application note slope stability analysis worked example. Slope stability analysis by the limit equilibrium method. A set of 5 basic slope stability problems, together with 5 variants, was distributed in the australian geomechanics profession and overseas as part of a survey sponsored by acads association for computer aided design, in 1988.
Slope stability analysis by finite elements colorado school of mines. The probabalistic sara stability analysis for road access program is still under development. This study was performed to evaluate the effect of shape and length of slope and soil depth for slope stability analysis and to compare infinite slope analysis with circular failure analysis. If you would like to participate, you can choose to edit this article, or visit the project page for more information.
Rs2 2d geotechnical finite element analysis rocscience. Rs2 formerly rs 2 or phase 2 is a powerful 2d finite element program for soil and rock applications. The cross sections used for our 2d slope stability analyses are based on cross section cc figure 4. 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. This type of analysis is also utilized to determine. Cheng et al threedimensional slope stability problem and wei et al. The term landslide refers to a situation of instability affecting natural slopes and involving large volumes of soil. An overall stability situation is where there is loss of overall stability of the ground and associated structures, i. Soil nailing is a common and effective method for improving the stability of earth or rock slopes. Stability analysis procedures determine a factor of safety for the slope given the distribution of static positive pressures along the slip surface.
For instance, merge the slope stability method stubs into this article. Slope stability analysis of an earth dam diyala journal of engineering sciences, vol. Gravity is the force that acts everywhere on the earths surface, pulling everything in a direction toward the center of the earth. Rock slope stability analysis utilization of advanced numerical techniques dr. Stability analysis geotechnical software geo5 fine. Use porewater pressures from seepw, seep3d, sigmaw, or quakew. Slope stability is part of wikiproject geology, an attempt at creating a standardized, informative, comprehensive and easytouse geology resource.
In this method, the only way to evaluate the influence of climatic conditions. The antislide pile program is used for design of pile walls stabilizing slope movement or increasing safety factor of the slope. Pdf the probabilistic seismic analysis provides a tool for considering the uncertainty of the soil parameters and earthquake characteristics. Slope stability, triggering events, mass movement hazards. It also adds to the aesthetic view of the earth structure. Fraction of failure strength of soil in janbu analysis. Numerical modeling of slope effect of water level on the slope stability to evaluate the effect of water level on the behavior and the safety factor of slopes, a slope with 10 meters. Application note slope stability analysis worked example 4. Evaluation of slope stability with topography and slope. Theory of slope stability kenneth m cruikshank portland state. Proceedings of the second international conference on geotechnique, construction materials and environment. 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.
Seismic coefficients for pseudostatic slope analysis. Chapter 10 slope stability analysis nysdot geotechnical page 106 january 21, 2014 design manual 10. The rock stability program is designated for analysis of rock slope stability for a specified type of failure, including a planar or polygonal slip surface or rock wedge. Using 2d or 3d finite element computed porewater pressures in slopew makes it possible to deal with highly irregular saturatedunsaturated conditions or transient porewater pressure conditions in a stability analysis. Slope stability analyses include static and dynamic, analytical or empirical methods to evaluate the stability of earth and rockfill dams, embankments. In existing researches connected with landslide, natural slope was regard as a parallel slope, but it was found that many landslides were occurred on the concave and convex slopes besides parallel slopes. European conference on stability of earth slopes sweden, 3, pp. Pdf stability analysis of embankments and slopes researchgate. Assessment of stability of slopes colorado school of mines. Slope stability, triggering events, mass movement hazards factors that influence slope stability gravity the main force responsible for mass movement is gravity. Slopes are required in the construction of highway and railway embankments, earth dams, levees, canals etc.
Slope w is the leading slope stability software for soil and rock slopes. The slip surface is considered as circular bishop, felleniuspetterson, janbu, morgensternprice or spencer methods or polygonal sarma, janbu, morgensternprice or. The study showed the values of factor of safety for upstream slope increase for a low rate of reservoir drawdown 3. The methods described are applicable to landslides in. The effect of water level on the stability of slopes. 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. The stability condition of slopes is a subject of study and research in soil mechanics, geotechnical engineering and engineering geology. Using 2d or 3d finite element computed porewater pressures in slope w makes it possible to deal with highly irregular saturatedunsaturated conditions or transient porewater pressure conditions in a stability analysis. B this article has been rated as bclass on the projects quality scale. Pdf dynamic reliability analysis of earth dams slope stability. It is essential that the engineering geologist be intimately familiar with all of these methods because they provide ways of. The limit equilibrium method is the most common approach for analyzing slope stability in both two and three dimensions. Gravitational force force due to seepage water erosion of the surface of slopes due to flowing water the sudden lowering of water adjacent to a slope.
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. Safety factor sf calculation for a slope a without tension crack b with a waterfilled tension crack. 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. Pdf in this paper the limit equilibrium method of stability analysis of embankments and slopes is. There seem to be many articles scattered as stubs related to larger ideas in the geotech categories. Soil bioengineering is a term that describes the use of living plant materials to build structures that provide slope support.
Stability analysis of a slope and finding critical slip surface. Global stability with relict slip surface in this scenario, the presence of the relict slip surface was assumed. 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. Factors affecting the stability analysis of earth dam. Bvs viswanadham, department of civil engineering, iit. Threedimensional slope stability problem with a surcharge. It is clear however that earthquakes do influence slope stability and can lead to slope failures on a catastrophic scale see, for example, seed. Seminar on slope stability and landslides, chinese institute of engineers. Attention has to be paid to geology, surface drainage, groundwater, and the shear strength of soils in assessing slope stability.
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. This is due to the removal of the balancing hydraulic forces acting on the dams and the undrained condition within the upstream slope soils. Stability of a mechanically stabilized earth wall geoslope international ltd. The slope stability calculated for bishop, janbu, spencer and gle is summarized in the graph below. Erik eberhardt university of british columbia geological engineeringearth and ocean sciences, ubc, 6339 stores rd. Currently used slope stability analyses assume the pore water pressures above the phreatic surface to be equal to zero. These analyses are often completed using slope stability charts and the dsara deterministic stability analysis for road access slope stability program. Instead of assuming a circular failure surface, the slope was analyzed for noncircular failure by optimizing surfaces in a path search. The drawdown of reservoirs can significantly affect the stability of upstream slopes of earth dams. Slopew is the leading slope stability software for soil and rock slopes. The slip surface is considered as circular bishop, felleniuspetterson, janbu, morgensternprice or spencer methods or polygonal sarma, janbu, morgensternprice or spencer methods. Factors affecting the stability analysis of earth dam slopes. The finiteelement program is for 2d, plane strain, slope stability analysis by finite elements using eightnode quadri lateral elements of elasticviscoplastic soil.
The aims of slope stability analyses are to understand the development and form of natural slopes and the processes responsible for different natural features. Accordingly, an important objective of this course is to apply the theory of earth pressures and use the calculated lateral pressures to design earth retaining structures. Gravity is the force that acts everywhere on the earth s surface, pulling everything in a direction toward the center of the earth. Slope w can effectively analyze both simple and complex problems for a variety of slip surface shapes, porewater pressure conditions, soil properties, and loading conditions. Combining subsidence theory and slope stability analysis method for building damage. Mid this article has been rated as midimportance on the. We can see that the shear strength of a soil plays a critical role in the evaluation of stability for earth slopes and retaining structures. Slope stability analysis consists of determining and comparing the shear stress developed along the potential rupture surface with the shear strength of the soil. A simple but accurate method of stability analysis of embankments and slopes is developed to determine the critical earthquake acceleration that is required to bring a mass of soil, bounded by a. Slopes in mountainous regions require cohesion 8 undrained short term slope failure in clay.
Modelling the stability of natural slopes adelaide research. Current practices in slope stability analysis and computer programs application to slope stability analysis for existing embankment dams guidance papers for static slope stability analysis minor corrections and editorial changes. Rock slope stability analysis utilization of advanced. Embankone dimensional compression due to embankment loads users manual 1992. Trevor orr trinity college dublin convenor tc250sc7eg3. The term slope means a portion of the natural slope whose original profile has been modified by artificial interventions relevant with respect to stability. We analyzed seismic displacements using simplified spreadsheetbased methods developed by bray and travasarou 2007. When the earth slope is provided with vegetation with small grassy plants, the roots of the plants penetrate into the earth slope and give the effect of reinforced earth. It also highlights some of the differences in approach to that adopted by the limit equilibrium method of slices.
Jan 28, 2011 in existing researches connected with landslide, natural slope was regard as a parallel slope, but it was found that many landslides were occurred on the concave and convex slopes besides parallel slopes. Slope stability verification manual deep excavation llc page 11 e. How does the slope angle play a role in slope stability. Tons of earth and vegetation washed away from clearcut hillsides into stillman creek, a tributary of the south fork of the chehalis river. Most of the analytical work concerned with the stability of slopes subjected to earthquakes has been performed in connection with earth and rockfill dams where there is great potential for damage. However, its use must be calibrated with observations from case histories or with reliable results from more advanced analyses. Slope stability refers to the condition of inclined soil or rock slopes to withstand or undergo movement. Ce 375 earth slopes and retaining structures unique no 15635. Symbol parameter dimensions f factor of safety against sliding along sheet joint calculated. Chapter 10 slope stability analysis nysdot geotechnical page 104 january 21, 2014 design manual 10. This program is used to perform slope stability analysis embankments, earth cuts, anchored retaining structures, mse walls, etc. Slope failure can often be catastrophic, involving the loss of considerable property and many lives. The focus in this chapter is on soil slopes and mechanisms involving shear failure within the soil mass.
This was applied in the model by selecting all the boundary lines between the mudstone and weathered mudstone unshow the water table, to facilitate. 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. A wide variety of slope stability software use the limit equilibrium concept with automatic critical slip surface determination. In the lecture part of this course we will discuss a variety of methods of analysis of slope stability and instability. Typical slope stability software can analyze the stability of generally layered soil slopes, embankments, earth cuts, and anchored sheeting structures. 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 is an exposed ground surface that stands at an angle with the horizontal. On a flat surface the force of gravity acts downward. They are certainly major factors in cut slope stability and in. How do friction and cohesion work together to stabilize slopes. Attention has to be paid to geology, surface drainage, groundwater, and the. They are certainly major factors in cut slope stability and in the stability of fill slopes involving both internal and external slope failures. Slope stability slope stability slope stability, triggering events, mass wasting hazards gravity the main force responsible for mass wasting is gravity.
Rs2 can be used for a wide range of engineering projects including excavation design, slope stability, groundwater seepage, probabilistic analysis, consolidation, and dynamic analysis capabilities complex, multistage models can be easily created and quickly analyzed tunnels in weak or. The slope stability analysis of complex earth structures such as heap leach operations, waste rock piles, or tailings dams is becoming more common. B ecause soil slopes are not rigid and the peak acceleration generated during an earthquake last fo r only a very short period. Methods for analysis of slope stability are described and are illustrated by examples in the appendixes.
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