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Introduction:
• Slopes either occur naturally or are engineered by humans.
• An understanding of geology, hydrology, and soil properties is
central to applying slope stability principles properly.
• Analyses must be based upon a model that accurately
represents site surface conditions, ground behavior, and
applied loads.
• Type of Analysis
Aim of slope
• Assess the stability of slopes under short-term
• Assess the possibility of slope failure / satbility
• Understand failure mechanisms and the influence
• Enable the redesign of failed slopes and the planning and design
• The effect of seismic loadings on slopes
• Safe and economic design of excavations, embankments, earth
dams, landfills, and spoil heaps .
FACTORS AFFECTING SLOPE FAILURE
Introduction
Geological discontinuities
Effect of Water
Geotechnical Properties of Material
Mining Methods
State of stress
Geometry slope:
Temperature
Erosion
Seismic effect
Vegetation
TYPES OF ROCK SLOPE FAILURE
Introduction
Plane failure
Wedge Failure:
Toppling failure
Rockfalls
Rotational Failure
Rock Slope Stability Analysis: Limit Equilibrium Method
Planar Failure Analysis Sliding analysis of a block Plane failure analysis along a discontinuity Water is filled in discontinuitiesTension crack present in the upper slope surface Tension crack present in the slope surface The tension crack is filled with water with upper slope angle Effect of rock bolts
Wedge Failure Analysis Analysis of wedge failure considering only frictional resistance Analysis of wedge failure with cohesion and friction angle
Toppling Failure Analysis Kinematics of block toppling failure Limit equilibrium analysis for toppling failure Stability analysis of flexural toppling
CIRCULAR FAILURE ANALYSIS
Introduction
Stability analysis of slope
Stability analysis for Cohesionless Soil
Total Stress Analysis (Swedish slip circle
method)
Ordinary slip circle method
Bishop’s Simplified Method of Slices
General Method of slices
SLOPE STABILITY ANALYSIS BY NUMERICAL MODELLING
Introduction Continuum modelingDiscontinuum ModelingHybrid approach
Important considerationsContinuum versus discontinuum modelsSelecting appropriate zone size Initial conditionsBoundary conditionsWater pressureExcavation sequence
Important failure indicators in slope analysisFactor of SafetyUnbalanced ForceGridpoint VelocitiesPlastic IndicatorsDisplacement Failure Surface
STABILITY ANALYSIS IN PRESENCE OF WATER
Introduction Common terms used in simulation of water Important Geotechnical properties related to water
Permeability Hydraulic Conductivity Factor affecting soil permeability and hydraulic conductivity Matrix suction Consistency of soil
Pore PressuresInfiltrationRainfall Infiltration Model.Simulation of water
SEISMIC ANALYSIS
Introduction
Types of seismic wave
Dynamic Soil Properties
Field Measurements of Dynamic Modulus
Ground Motion Estimates
Factors Affecting Ground Motion:
Simulation of seismic effect
Pseudo-static approach
Wedge Method
Method of Slices
Inertia Slope Stability – Newmark Method
SLOPE STABILIZATION
Introduction Removal And Repair Excavation & repair Catchment & Wire NettingGrading & SerratingBenchingResloping and unloadingLightweight FillCounterbermsTrimmingShear KeysScaling
Drainage and Water ControlSurface DrainageSubsurface Drainage
Stabilization Through Support Steel reinforcement Rock anchorRock Bolts Rock DowelsSoil NailingPilesGeosynthetic Reinforcement
Retaining Walls Gravity Walls Cantilever Retaining Walls Sheet Piling Retaining WallsAnchored retaining wall Gabions
Other Methods For Stabilization Grouting and ShotcreteVegetation
SLOPE MONITORING: TECHNIQUES AND INSTRUMENTS
Introduction Slope failure mechanism
Types of Slope Movement Initial responseRegressive and progressive movementLong-term creep
Sub-Surface Monitoring Methods
Borehole probesTime–domain reflectometryInclinometers Extensometers
Measurement of water level and pressure Standpipe Piezometer Pneumatic Piezometer Vibrating Wire Piezometer
Surface Monitoring MethodsCrack MonitorsSurveyingPhotographic Image AnalysisTotal Station Global positioning system (GPS)Acoustic emission technique Laser image scanning systemSlope Stability Radar system Synthetic aperture radar
landslides
IntroductionSlope Failure
Slumps Rock Falls and Debris Falls Rock and Debris Slides
Sediment Flows Solifluction Debris FlowsMudflows Creeps Earthflows
Debris Avalanches
Historical landslides (wiki )
Major factors affecting landslides
Mine Waste Dump
Introduction Method of Construction in lift sectionMethods of Stability CalculationShear Strength of dump material
Particle shape, roundness and grain surface texture Effect of moisture condition on shear strength
Factors Affecting Dump StabilityDump Configuration Foundation ConditionsDump Material PropertiesDumping method Dumping RateSeismicity and Dynamic StabilityTopographyDump drainage
Material properties and testing Bulk Gradation Plasticity of Fines Index Properties and Classification Hydraulic Conductivity Consolidation Strength Mineralogy and Soil Chemistry In Situ Density Compaction
Tailing Dam
Failure Modes in tailing dams Rotational SlidingFoundation FailureOvertoppingErosionPipingTailings Impoundment Design Mill Location Topography Geology and Ground Water Tailings impoundmentsTailings storage facilities
Methods for Tailings DisposalUpstream MethodDownstream Method Centerline Method
Sensitivity, probability and reliability analysis
Sensitivity AnalysisProbabilistic Design MethodsReliability Analysis
Classification systems in slope stability analysis
GeneralSlope Mass Rating (SMR)Chinese Slope Mass Rating System (CSMR)Rock slope rating (RSR)Slope stability rating (SSR) classification systemDump mass rating
Introduction of softcomputing approach in slope stability
Artificial Neural NetworkFuzzy Inference System