Author Biographies 1 Introduction 1.1 Outline of the book 1.2 Types of embankment dams and their main features 1.3 Types of concrete dams and their main features 2 Key geological issues 2.1 Basic definitions 2.2 Types of anisotropic fabrics 2.3 Defects in rock masses 2.3.1 Joints 2.3.2 Sheared and crushed zones (faults) 2.3.3 Soil infill seams (or just infill seams) 2.3.4 Extremely weathered (or altered) seams 2.3.5 The importance of using the above terms to describe defects in rock 2.4 Defects in soil masses 2.5 Stresses in rock masses 2.5.1 Probable source of high horizontal stresses 2.5.2 Stress relief effects in natural rock exposures 2.5.3 Effects in claystones and shales 2.5.4 Special effects in valleys 2.5.5 Rock movements in excavations 2.6 Weathering of rocks 2.6.1 Mechanical weathering 2.6.2 Chemical decomposition 2.6.3 Chemical weathering 184.108.40.206 Susceptibility of common minerals to chemical weathering 220.127.116.11 Susceptibility of rock substances to chemical weathering 2.6.4 Weathered rock profiles and their development 18.104.22.168 Climate and vegetation 22.214.171.124 Rock substance types and defect types and pattern 126.96.36.199 Time and erosion 188.8.131.52 Groundwater and topography 184.108.40.206 Features of weathered profiles near valley floors 2.6.5 Complications due to cementation 2.7 Chemical alteration 2.8 Classification of weathered rock 2.8.1 Recommended system for classification of weathered rock substance 2.8.2 Limitations on classification systems for weathered rock 2.9 Rapid weathering 2.9.1 Slaking of mudrocks 2.9.2 Crystal growth in pores 2.9.3 Expansion of secondary minerals 2.9.4 Oxidation of sulphide minerals 220.127.116.11 Sulphide oxidation effects in rockfill dams - some examples 18.104.22.168 Possible effects of sulphide oxidation in rockfill dams 22.214.171.124 Sulphide oxidation - implications for site studies 2.9.5 Rapid solution 2.9.6 Surface fretting due to electro-static moisture absorption 2.10 Landsliding at dam sites 2.10.1 First-time and "reactivated'' slides 126.96.36.199 Reactivated slides 188.8.131.52 First-time slides 2.10.2 Importance of early recognition of evidence of past slope instability at dam sites 2.10.3 Dams and landslides: Some experiences 184.108.40.206 Talbingo Dam 220.127.116.11 Tooma Dam 18.104.22.168 Wungong Dam 22.214.171.124 Sugarloaf Dam 126.96.36.199 Thomson Dam 2.11 Stability of slopes around storages 2.11.1 Vital slope stability questions for the feasibility and site selection stages 188.8.131.52 Most vulnerable existing or proposed project features, and parts of storage area? - Question 1 184.108.40.206 Currently active or old dormant landslides? - Questions 2 and 4 to 7 220.127.116.11 Areas where first-time landsliding may be induced (Questions 3 to 7) 18.104.22.168 What is the likely post failure velocity and travel distance? 22.214.171.124 What is the size of impulse waves which may be created? 2.12 Watertightness of storages 2.12.1 Models for watertightness of storages in many areas of non-soluble rocks 2.12.2 Watertightness of storage areas formed by soluble rocks 2.12.3 Features which may form local zones of high leakage, from any storage area 2.12.4 Watertightness of storages underlain by soils 2.12.5 Assessment of watertightness 126.96.36.199 Storages in non-soluble rock areas - assessment of watertightness 188.8.131.52 Storages in soluble rock areas - assessment of watertightness 184.108.40.206 Storages formed in soils - assessment of watertightness 2.12.6 Methods used to prevent or limit leakages from storages 3 Geotechnical questions associated with various geological environments 3.1 Granitic rocks 3.1.1 Fresh granitic rocks, properties and uses 3.1.2 Weathered granitic rocks, properties, uses and profiles 3.1.3 Stability of slopes in granitic rocks 3.1.4 Granitic rocks: check list 3.2 Volcanic rocks (intrusive and flow) 3.2.1 Intrusive plugs, dykes and sills 3.2.2 Flows 220.127.116.11 Flows on land 18.104.22.168 Undersea flows 3.2.3 Alteration of volcanic rocks 3.2.4 Weathering of volcanic rocks 3.2.5 Landsliding on slopes underlain by weathered basalt 3.2.6 Alkali-aggregate reaction 3.2.7 Volcanic rocks (intrusive and flow) check list of questions 3.3 Pyroclastics 1 3.3.1 Variability of pyroclastic materials and masses 3.3.2 Particular construction issues in pyroclastics 3.3.3 Pyroclastic materials - check list of questions 3.4 Schistose rocks 3.4.1 Properties of fresh schistose rock substances 3.4.2 Weathered products and profiles developed in schistose rock 3.4.3 Suitability of schistose rocks for use as filter materials, concrete aggregates and pavement materials 3.4.4 Suitability of schistose rocks for use as rockfill 3.4.5 Structural defects of particular significance in schistose rocks 22.214.171.124 Minor faults developed parallel and at acute angles to the foliation 126.96.36.199 Kink bands 188.8.131.52 Mica-rich layers 3.4.6 Stability of slopes formed by schistose rocks 3.4.7 Schistose rocks - check list of questions 3.5 Mudrocks 3.5.1 Engineering properties of mudrocks 3.5.2 Bedding-surface faults in mudrocks 3.5.3 Slickensided joints or fissures 3.5.4 Weathered products and profiles in mudrocks 3.5.5 Stability of slopes underlain by mudrocks 3.5.6 Development of unusually high pore pressures 3.5.7 Suitability of mudrocks for use as construction materials 3.5.8 Mudrocks - check list of questions 3.6 Sandstones and related sedimentary rocks 3.6.1 Properties of the rock substances 3.6.2 Suitability for use as construction materials 3.6.3 Weathering products 3.6.4 Weathered profile and stability of slopes 3.6.5 Sandstones and similar rocks - list of questions 3.7 Carbonate rocks 3.7.1 Effects of solution 184.108.40.206 Rock masses composed of dense, fine grained rock substances comprising more than 90% of carbonate (usually Category O) 220.127.116.11 Rock masses composed of dense fine grained rock substance containing 10% to 90% of carbonate (usually Category O) 18.104.22.168 Rock masses composed of porous, low density carbonate rock substance (usually Category Y) 3.7.2 Watertightness of dam foundations 22.214.171.124 Dams which have experienced significant leakage problems 3.7.3 Potential for sinkholes to develop beneath a dam, reservoir or associated works 3.7.4 Potential for continuing dissolution of jointed carbonate rock in dam foundations 3.7.5 Potential for continuing dissolution of aggregates of carbonate rock particles and of permeable carbonate substances (Category O carbonate, in each case) 3.7.6 Discussion - potential for continuing dissolution of carbonate rocks in foundations 126.96.36.199 Category O carbonate rocks 188.8.131.52 Category Y carbonate rocks 3.7.7 Potential problems with filters' composed of carbonate rocks 184.108.40.206 Category O carbonate rocks 220.127.116.11 Category Y carbonate materials 3.7.8 Suitability of carbonate rocks for embankment materials 3.7.9 Suitability of carbonate rocks for concrete and pavement materials 3.7.10 Stability of slopes underlain by carbonate rocks 3.7.11 Dewatering of excavations in carbonate rocks 3.7.12 Carbonate rocks - check list of questions 3.8 Evaporites 3.8.1 Performance of dams built on rocks containing evaporites 3.8.2 Guidelines for dam construction at sites which contain evaporites 3.8.3 Evaporites - checklist of questions 3.9 Alluvial soils 3.9.1 River channel deposits 3.9.2 Open-work gravels 3.9.3 Oxbow lake deposits 3.9.4 Flood plain, lacustrine and estuarine deposits 3.9.5 Use of alluvial soils for construction 3.9.6 Alluvial soils, list of questions 3.10 Colluvial soils 3.10.1 Occurrence and description 18.104.22.168 Scree and talus 22.214.171.124 Slopewash soils 126.96.36.199 Landslide debris 3.10.2 Properties of colluvial soils 188.8.131.52 Scree and talus 184.108.40.206 Slopewash 220.127.116.11 Landslide debris 3.10.3 Use as construction materials 3.10.4 Colluvial soil - list of questions 3.11 Laterites and lateritic weathering profiles 3.11.1 Composition, thicknesses and origin of lateritic weathering profiles 3.11.2 Properties of lateritic soils 3.11.3 Use of lateritic soils for construction 3.11.4 Karstic features developed in laterite terrain 3.11.5 Recognition and interpretation of silcrete layer 3.11.6 Lateritic soils and profiles - list of questions 3.12 Glacial deposits and landforms 3.12.1 Glaciated valleys 3.12.2 Materials deposited by glaciers 18.104.22.168 Properties of till materials 22.214.171.124 Disrupted bedrock surface beneath glaciers 3.12.3 Glaciofluvial deposits 3.12.4 Periglacial features 3.12.5 Glacial environment - list of questions 4 Planning, conducting and reporting of geotechnical investigations 4.1 The need to ask the right questions 4.1.1 Geotechnical engineering questions 4.1.2 Geological questions 126.96.36.199 Questions relating to rock and soil types, climate and topography 188.8.131.52 Questions relating to geological processes, i.e. to the history of development of the site 4.1.3 Geotechnical questions for investigations of existing dams 4.2 Geotechnical input at various stages of project development 4.3 An iterative approach to the investigations 4.4 Progression from regional to local studies 4.4.1 Broad regional studies 184.108.40.206 Objectives 220.127.116.11 Activities 4.4.2 Studies at intermediate and detailed scales 18.104.22.168 Objectives 22.214.171.124 Activities 4.5 Reporting 4.6 Funding of geotechnical studies 4.7 The site investigation team 5 Site investigation techniques 5.1 Topographic mapping and survey 5.2 Interpretation of satellite images aerial photographs and photographs taken during construction 5.2.1 Interpretation of satellite images 5.2.2 Interpretation of aerial photographs 126.96.36.199 Coverage 188.8.131.52 Interpretation 5.2.3 Photographs taken during construction 5.3 Geomorphological mapping 5.4 Geotechnical mapping 5.4.1 Use of existing maps and reports 5.4.2 Geotechnical mapping for the project 184.108.40.206 Regional mapping 220.127.116.11 Geotechnical mapping 5.5 Geophysical methods, surface and downhole 5.5.1 Surface geophysical methods 18.104.22.168 Seismic refraction 22.214.171.124 Self potential 126.96.36.199 Electrical resistivity 188.8.131.52 Electromagnetic conductivity 184.108.40.206 Magnetic 220.127.116.11 Microgravity 18.104.22.168 Ground penetrating radar 5.5.2 Down-hole logging of boreholes 5.5.3 Cross-hole and up-hole seismic 5.6 Test pits and trenches 5.6.1 Test pits 5.6.2 Trenches 5.7 Sluicing 5.8 Adits and shafts 5.9 Drill holes 5.9.1 Drilling objectives 5.9.2 Drilling techniques and their application 5.9.3 Auger drilling 5.9.4 Percussion drilling 5.9.5 Rotary drilling 5.9.6 Sonic drilling 5.10 Sampling 5.10.1 Soil samples 5.10.2 Rock samples 5.11 In situ testing 5.11.1 In situ testing in soils 5.11.2 In situ testing of rock 22.214.171.124 Borehole orientation 126.96.36.199 Borehole impression packer 188.8.131.52 Borehole imaging 5.12 Groundwater 5.13 In situ permeability tests on soil 5.14 In situ permeability tests in rock 5.14.1 Lugeon value and equivalent rock mass permeability 5.14.2 Test methods 5.14.3 Selection of test section 5.14.4 Test equipment 184.108.40.206 Packers 220.127.116.11 Water supply system 18.104.22.168 Selection of test pressures 5.14.5 Test procedure 22.214.171.124 Presentation and interpretation of results 5.15 Use of surface survey and borehole inclinometers 5.15.1 Surface survey 5.15.2 Borehole inclinometers 5.16 Common errors and deficiencies in geotechnical investigation 6 Shear strength, compressibility and permeability of embankment materials and soil foundations 6.1 Shear strength of soils 6.1.1 Drained strength - definitions 6.1.2 Development of drained residual strength R 6.1.3 Undrained strength conditions 6.1.4 Laboratory testing for drained strength parameters, and common errors 126.96.36.199 Triaxial test 188.8.131.52 Direct shear test 184.108.40.206 Ring shear test 220.127.116.11 Comparison of field residual with laboratory residual strength obtained from direct shear and ring shear 6.1.5 Laboratory testing for undrained strength 6.1.6 Estimation of the undrained strength from the Over-Consolidation Ratio (OCR), at rest earth pressure coefficient Ko, and effective stress strengths 18.104.22.168 Estimation of undrained strength from OCR 22.214.171.124 Estimation of undrained strength from effective stress shear parameters 6.1.7 Estimation of the undrained strength of cohesive soils from in situ tests 126.96.36.199 Cone Penetration and Piezocone Tests 188.8.131.52 Vane shear 184.108.40.206 Self Boring Pressuremeter 6.1.8 Shear strength of fissured soils 220.127.116.11 The nature of fissuring, and how to assess the shear strength 18.104.22.168 Triaxial testing of fissured soils 6.1.9 Estimation of the effective friction angle of granular soils 22.214.171.124 Methods usually adopted 126.96.36.199 In situ tests 188.8.131.52 Laboratory tests 184.108.40.206 Empirical estimation 6.1.10 Shear strength of partially saturated soils 6.2 Shear strength of rockfill 6.3 Compressibility of soils and embankment materials 6.3.1 General principles 220.127.116.11 Within the foundation 18.104.22.168 Within the embankment 6.3.2 Methods of estimating the compressibility of earthfill, filters and rockfill 22.214.171.124 Using data from the performance of other dams - earthfill 126.96.36.199 Using data from the performance of other dams - rockfill 188.8.131.52 In situ testing 184.108.40.206 Laboratory testing 220.127.116.11 Tensile properties of plastic soils 6.4 Permeability of soils 6.4.1 General principles 6.4.2 Laboratory test methods 6.4.3 Indirect test methods 18.104.22.168 Oedometer and triaxial consolidation test 22.214.171.124 Estimation of permeability of sands from particle size distribution 6.4.4 Effects of poor sampling on estimated permeability in the laboratory 6.4.5 In situ testing methods 7 Clay mineralogy, soil properties, and dispersive soils 7.1 Introduction 7.2 Clay minerals and their structure 7.2.1 Clay minerals 7.2.2 Bonding of clay minerals 126.96.36.199 Primary bonds 188.8.131.52 Secondary bonds 7.2.3 Bonding between layers of clay minerals 7.3 Interaction between water and clay minerals 7.3.1 Adsorbed water 7.3.2 Cation exchange 7.3.3 Formation of diffuse double layer 7.3.4 Mechanism of dispersion 7.4 Identification of clay minerals 7.4.1 X-ray diffraction 7.4.2 Differential Thermal Analysis (DTA) 7.4.3 Electron microscopy 7.4.4 Atterberg limits 7.4.5 The activity of the soil 7.5 Engineering properties of clay soils related to the types of clay minerals 7.5.1 Dispersivity 7.5.2 Shrink and swell characteristics 7.5.3 Shear strength 7.5.4 Erosion properties 7.6 Identification of dispersive soils 7.6.1 Laboratory tests 184.108.40.206 Emerson class number 220.127.116.11 Soil Conservation Service test 18.104.22.168 Pinhole dispersion classification 22.214.171.124 Chemical tests 126.96.36.199 Recommended approach 7.6.2 Field identification and other factors 7.7 Use of dispersive soils in embankment dams 7.7.1 Problems with dispersive soils 7.7.2 Construction with dispersive soils 188.8.131.52 Provide properly designed and constructed filters 184.108.40.206 Proper compaction of the soil 220.127.116.11 Careful detailing of pipes or conduits through the embankment 18.104.22.168 Lime or gypsum modification of the soil 22.214.171.124 Sealing of cracks in the abutment and cutoff trench 7.7.3 Turbidity of reservoir water 8 Internal erosion and piping of embankment dams and in dam foundations 8.1 The importance of internal erosion and piping to dam safety 8.2 Description of the internal erosion and piping process 8.2.1 The overall process leading to failure of a dam 8.2.2 Initiation of internal erosion 8.2.3 Continuation of erosion 8.2.4 Progression of erosion 8.2.5 Detection and intervention 8.2.6 Breach 8.3 Concentrated leak erosion 8.3.1 The overall process 8.3.2 Situations where cracking and low stress zones may be present in an embankment or the foundation 126.96.36.199 Cracking and hydraulic fracture due to cross valley differential settlement of the core 188.8.131.52 Cracking and hydraulic fracture due to cross valley arching 184.108.40.206 Cracking and hydraulic fracture due to differential settlement in the foundation under the core 220.127.116.11 Cracking and hydraulic fracture due to small scale irregularities in the foundation profile under the core 18.104.22.168 Cracking due to lack of support for the core by the shoulders of the embankment 22.214.171.124 Cracking and hydraulic fracture due to arching of the core onto the shoulders of the embankment 126.96.36.199 Crack or gap adjacent to a spillway or abutment walls and where concrete dams abut embankment dams 188.8.131.52 Crack or hydraulic fracture in poorly compacted layers in the embankment 184.108.40.206 Internal erosion associated with conduits embedded in the embankment 220.127.116.11 Cracking due to desiccation 18.104.22.168 Transverse cracking caused by settlement during earthquakes 22.214.171.124 Cracking or high permeability layers due to freezing 126.96.36.199 Internal erosion initiated by the effects animal burrows and vegetation 188.8.131.52 Relative importance of conduits, spillway walls cracking mechanisms, and poorly compacted zones 8.3.3 Estimation of crack width and depth of cracking 184.108.40.206 Cracking due to differential settlement, adjacent walls 220.127.116.11 Cracks formed by collapse settlement of poorly compacted soil 8.3.4 The mechanics of erosion in concentrated leaks 18.104.22.168 The procedure for assessing whether erosion will initiate 22.214.171.124 The estimation of hydraulic shear stresses in cracks and pipes 126.96.36.199 Erosion properties of soils in the core of embankment dams - basic principles 188.8.131.52 Effect of degree of saturation of the soil 184.108.40.206 Effect of the testing method on the critical shear stress to initiate erosion ( c) and the erosion rate index 220.127.116.11 Effect of dispersion, slaking, soil structure and shear strength on erosion properties 8.3.5 Comparison of the hydraulic shear stress in the crack ( ) to the critical shear stress which will initiate erosion for the soil in the core of the embankment ( c) 8.4 Backward erosion 8.4.1 General description of backward erosion 8.4.2 Experimental modelling of backward erosion piping 8.4.3 Methods for predicting whether backward erosion piping will initiate and progress 18.104.22.168 Empirical rules for estimating a factor of safety 22.214.171.124 Terzaghi and Peck (1948) 126.96.36.199 Sellmeijer and co-workers at Deltares method 188.8.131.52 Schmertmann method 8.4.4 Some field observations 8.4.5 Suggested approach to design for and assessing backward erosion piping 8.4.6 Guidance on whether the overlying soil will form a roof to the pipe 8.4.7 Methods for prediction of initiation and progression of global backward erosion 8.5 Suffusion of internally unstable soils 8.5.1 General description of suffusion 8.5.2 Methods of identifying soils which are internally unstable and potentially subject to suffusion 184.108.40.206 General requirements 220.127.116.11 Some methods for assessing whether a soil is internally unstable 18.104.22.168 Some general comments 8.5.3 Assessment of the gradation after suffusion 8.5.4 Assessment of the seepage gradient which will cause suffusion 8.5.5 Some general comments 22.214.171.124 Need for project specific laboratory tests 126.96.36.199 Do not use "average'' soil gradations 188.8.131.52 Allow for the effects of segregation when assessing suffusion 8.6 Contact erosion 8.6.1 General description of contact erosion 8.6.2 Methods for predicting initiation and progression of contact erosion 184.108.40.206 Non plastic sand below a coarse soil layer 220.127.116.11 Non plastic silt and clay (particles <75 m) below a coarse layer 18.104.22.168 Non-plastic silt above a coarse soil layer 22.214.171.124 General comment 8.6.3 Contact erosion or scour of the dam core into open joints in rock in the foundation 8.7 Continuation and filter action 8.8 Progression of erosion 8.8.1 General description 8.8.2 Overall approach for assessing progression for concentrated leak erosion 8.8.3 Assessing whether the soil will hold a roof to a developing pipe 8.8.4 Assessing whether crack filling action will occur 126.96.36.199 Internal erosion in the embankment 188.8.131.52 Internal erosion through the foundation 184.108.40.206 Internal erosion of the embankment into or at the foundation 8.8.5 Assessing whether upstream flow limitation will occur 8.8.6 Assessing the rate of development of the pipe 8.9 Detection of internal erosion and piping 8.9.1 General principles 8.9.2 Some information on the rate of internal erosion and piping 8.9.3 The likelihood of detection and intervention 8.10 Intervention and repair 8.11 Initiation of breach 8.11.1 General principles 8.11.2 Breach by gross enlargement 8.11.3 Breach by slope instability 8.11.4 Breach by unravelling or sloughing 8.11.5 Breach by sinkhole development leading to loss of freeboard 8.12 Assessment of the likelihood of internal erosion and piping in existing dams 8.12.1 General procedure 8.12.2 The importance of having complete and reliable information upon which to make the assessment of internal erosion 220.127.116.11 Geometric model 18.104.22.168 Geological model of the foundation 22.214.171.124 Geotechnical model of the embankment and foundations 126.96.36.199 Hydraulic or seepage model 188.8.131.52 Stress state in the dam and its foundation 184.108.40.206 General comments 8.12.3 Loading conditions 220.127.116.11 Reservoir level loading 18.104.22.168 Earthquake loading 8.12.4 Potential Failure Modes Analysis (PFMA) 8.12.5 Screening of potential failure modes 22.214.171.124 Screening of PFM on the zoning of the dam and the properties of the core of the embankment 126.96.36.199 Screening of PFM on foundation geology and properties 188.8.131.52 Screening of PFM on details of the embankment foundation geometry, compaction of the core, and conduits and retaining walls 8.12.6 Estimation of likelihoods of failure for the Potential Failure Modes applicable to the dam 184.108.40.206 Some general principles 220.127.116.11 Summary of how to estimate conditional probabilities within the event tree 18.104.22.168 Ways in which the safety of the dam against internal erosion and piping can be considered 22.214.171.124 Quantitative risk analysis methods for internal erosion and piping 9 Design, specification and construction of filters 9.1 General requirements for design and the function of filters 9.1.1 Functional requirements 9.1.2 Flow conditions acting on filters 9.1.3 Critical and non critical filters 9.1.4 Filter design notation and concepts 126.96.36.199 Notation 188.8.131.52 Filtering concepts 184.108.40.206 Laboratory test equipment 9.2 Design of critical and non-critical filters 9.2.1 Particle size based methods for designing no erosion filters with flow normal to the filter 220.127.116.11 Original USBR method 18.104.22.168 Sherard and Dunnigan method 22.214.171.124 Foster and Fell method 126.96.36.199 Vaughan and Soares method 9.2.2 Methods based on constriction or opening size 9.2.3 Methods based on the permeability of the filter 188.8.131.52 Delgardo and co-workers 184.108.40.206 Vaughan and Soares, Vaughan and Bridle method 9.2.4 Recommended method for design of critical no erosion filters, with flow normal to the filter 9.2.5 Recommended method for design of less critical and non-critical filters 220.127.116.11 Filters upstream of the dam core 18.104.22.168 Filters under rip-rap 9.2.6 Review of available methods for designing filters with flow parallel to the filter 9.2.7 Design criteria for pipe drains and pressure relief well screens 22.214.171.124 Pipe drains 126.96.36.199 Pressure relief well screens 9.2.8 Other factors affecting filter design and performance 188.8.131.52 Criteria to assess internal instability or suffusion 184.108.40.206 Segregation 220.127.116.11 Ability of the filter to hold a crack 18.104.22.168 Permeability 22.214.171.124 "Blow-out'' or "heave'' of the filter 9.3 Assessing filters and transition zones in existing dams 9.3.1 Some general issues and concepts 9.3.2 Continuing and excessive erosion criteria 9.3.3 Discussion of continuation scenarios in existing dams 126.96.36.199 Internal erosion in the embankment, from the embankment into the foundation or into openings in conduits passing through the embankment 188.8.131.52 Internal erosion in the foundation 184.108.40.206 Internal erosion of the embankment at or into the foundation 9.3.4 Assessment of the likelihood of continuation where a filter/transition zone does not satisfy no-erosion filter criteria 220.127.116.11 General principles 18.104.22.168 Details of how to apply the Foster and Fell (1999a, 2001) method for assessing the likelihood of continuation of erosion for filters and transitions which do not meet modern filter design criteria 9.3.5 Assessment of the likelihood of continuation for internal erosion into an open defect, joint or crack in the foundation, in a wall or conduit 9.4 Specification of particle size and durability of filters 9.4.1 Particle size distribution 9.4.2 Durability 22.214.171.124 Standard tests for durability and particle shape 126.96.36.199 Possible effects if carbonate rocks are used as filter materials 188.8.131.52 Effects if rocks containing sulphide minerals are used as filter materials 184.108.40.206 Other investigations for filter materials 9.4.3 Contractual difficulties associated with gradation and durability of filters 220.127.116.11 Fines content 18.104.22.168 Use of crushed rock for fine filters 9.5 Dimensions, placement and compaction of filters 9.5.1 Dimensions and method of placement of filters 22.214.171.124 Some general principles 126.96.36.199 Placement methods 9.5.2 Sequence of placement of filters and control of placement width and thickness 9.5.3 Compaction of filters 9.6 Use of geotextiles as filters in dams 9.6.1 Types and properties of geotextiles 9.6.2 Geotextile filter design criteria 188.8.131.52 General requirements 184.108.40.206 Filtering requirement 220.127.116.11 Clogging and blinding resistance 18.104.22.168 Permeability requirement 22.214.171.124 Durability or "survivability'' requirement 126.96.36.199 Use of geotextile filters in dams 188.8.131.52 Construction factors 184.108.40.206 Sources of detailed information 10 Embankment dams, their zoning and design for control of seepage and internal erosion and piping 10.1 Historic performance of embankment dams and the lessons to be learned 10.2 Types of embankment dams, their advantages and limitations 10.2.1 The main types of embankment dams and zoning 10.2.2 The general principles of control of seepage pore pressures and internal erosion and piping 10.2.3 Taking account of the likelihood and consequences of failure in selecting the type of embankment 10.2.4 Types of embankment dams, their advantages, limitations and applicability 10.3 Zoning of embankment dams and typical construction materials 10.3.1 General principles 10.3.2 Examples of embankment designs 10.3.2.1 Zoned earthfill dams 10.3.2.2 Earthfill dams with horizontal and vertical drains 10.3.2.3 Central core earth and rockfill dams 10.3.2.4 Sloping upstream core earth and rockfill dam 10.3.2.5 Concrete face rockfill dams 10.4 Selection of embankment type 10.4.1 Availability of construction materials 10.4.1.1 Earthfill 10.4.1.2 Rockfill 10.4.1.3 Filters and filter drains 10.4.2 Foundation conditions 10.4.3 Climate 10.4.4 Topography and relation to other structures 10.4.5 Saddle dam 10.4.6 Staged construction 10.4.7 Time for construction 10.5 General requirements and methods of control of seepage and internal erosion and piping in embankment dams and their foundations 10.6 Some particular features of rock and soil foundations which affect seepage and internal erosion control 10.7 Details of some measures for pore pressure and seepage flow control 10.7.1 Horizontal and vertical drains in the embankment 10.7.2 Treatment of the sides of the cutoff trench 10.7.3 Prevention of critical seepage gradients and heave of the foundation 10.7.4 Design of pressure relief wells 10.8 Control of foundation seepage and internal erosion and piping by cutoffs 10.8.1 General effectiveness of cutoffs 10.8.2 Cutoff trench 10.8.3 Slurry trench cutoff backfilled with bentonite-sand-gravel 10.8.4 Grout diaphragm wall 10.8.5 Diaphragm wall using rigid or plastic concrete 10.8.6 Methods of excavation of diaphragm walls 10.8.7 Permeability and performance of cutoff walls 10.8.8 We live in a three dimensional world 10.9 Examples of dam upgrades to address deficiencies in internal erosion and piping control 10.9.1 Upgrades to reduce the likelihood of continuation of erosion by providing filters and cutoffs 10.9.2 Upgrades to reduce the likelihood of breach 11 Analysis of stability and deformations 11.1 Analysis of stability and deformations methods of analysis 11.2 Limit equilibrium analysis methods 11.2.1 General characteristics 11.2.2 Some common problems 11.2.3 Three dimensional analysis 11.2.4 Shear strength of partially saturated soils 11.3 Selection of shear strength for design 11.3.1 Drained, effective stress parameters 220.127.116.11 Peak, residual or fully softened strength in clay soils? 18.104.22.168 Selection of design parameters in clay soils 22.214.171.124 Selection of design parameters - granular soils and rockfill 11.3.2 Undrained, total stress parameters 126.96.36.199 Triaxial compression, extension or direct simple shear strength 188.8.131.52 Selection of design parameters 11.3.3 Inherent soil variability 11.4 Estimation of pore pressures and selection of strengths for steady state, construction and drawdown conditions 11.4.1 Steady state seepage condition 184.108.40.206 Steady state pore pressures 220.127.116.11 Pore pressures under flood conditions 11.4.2 Pore pressures during construction and analysis of stability at the end of construction 18.104.22.168 Some general principles 22.214.171.124 Estimation of construction pore pressures by Skempton (1954) method 126.96.36.199 Estimation of construction pore pressures from drained and specified undrained strengths 188.8.131.52 Estimation of pore pressures using advanced theory of partially saturated soil 184.108.40.206 Undrained strength analysis 220.127.116.11 Summing up 11.4.3 Drawdown pore pressures and the analysis of stability under drawdown conditions 18.104.22.168 Some general issues 22.214.171.124 Estimation of drawdown pore pressures, excluding the effects of shear-induced pore pressures 126.96.36.199 Methods for assessment of the stability under drawdown conditions 188.8.131.52 Some detailed issues for drawdown analyses 11.5 Design acceptance criteria 11.5.1 Acceptable factors of safety 11.5.2 Post failure deformation assessment 11.6 Examples of unusual issues in analysis of stability 11.6.1 Hume No. 1 Embankment 11.6.2 Eppalock Dam 11.6.3 The lessons learnt 11.7 Analysis of deformations 11.7.1 Analyses of embankment cross sections 11.7.2 Cross valley deformation analyses 11.8 Probabilistic analysis of the stability of slopes 12 Design of embankment dams to withstand earthquakes 12.1 Effect of earthquake on embankment dams 12.2 Earthquakes and their characteristics 12.2.1 Earthquake mechanisms and ground motion 12.2.2 Earthquake magnitude and intensity 12.2.3 Attenuation and amplification of ground motion 12.2.4 Earthquakes induced by the reservoir 12.3 Evaluation of seismic hazard 12.3.1 Terminology 12.3.2 General principles of seismic hazard assessment 184.108.40.206 Probabilistic approach 220.127.116.11 Seismic hazard from known active or capable faults 12.3.3 Other forms of expression of seismic hazard 12.3.4 Selection of design seismic loading 18.104.22.168 Deterministic approach 22.214.171.124 Risk based approach 126.96.36.199 Which approach to use? 12.3.5 Modelling vertical ground motions 12.3.6 The need to get good seismological advice 12.4 Principles of risk based analyses for earthquake loads 12.4.1 General principles 12.4.2 Failure by loss of freeboard and overtopping 12.4.3 Failure by cracking and internal erosion and piping 12.5 Liquefaction of dam embankments and foundations 12.5.1 Definitions and the mechanics of liquefaction 188.8.131.52 Definitions 184.108.40.206 Some consideration of the mechanics of liquefaction of granular soils 220.127.116.11 Suggested flow chart for evaluation of soil liquefaction 12.5.2 Soils susceptible to liquefaction 18.104.22.168 Methods based on soil classification and in situ moisture content 22.214.171.124 Discussion and recommended approach 126.96.36.199 Methods based on geology and age of the deposit 12.5.3 The "simplified procedure'' for assessing liquefaction resistance of a soil 188.8.131.52 Background to the simplified method 184.108.40.206 Discussion of differences between the Youd et al. (2001), Seed et al. (2003) and Idriss and Boulanger (2008) methods 220.127.116.11 The simplified method - outline 18.104.22.168 Evaluation of Cyclic Stress Ratio (CSR) 22.214.171.124 Evaluation of Cyclic Resistance Ratio for M7.5 earthquakes (CRR7.5) from the Standard Penetration Tests using the Boulanger and Idriss (2012), Idriss and Boulanger (2008) method 126.96.36.199 Evaluation of the Cyclic Resistance Ratio for M7.5 earthquake (CRR7.5) from Cone Penetration Tests using the Idriss and Boulanger (2008) method 188.8.131.52 Evaluation of Cyclic Resistance Ratio for M7.5 earthquake (CRR7.5) from shear wave velocity using the Andrus and Stokoe (2000) method 184.108.40.206 Earthquake magnitude scaling factors and factor of safety against liquefaction 220.127.116.11 Corrections for overburden stress and static shear stress 18.104.22.168 Allowance for the age of the soil deposit 12.6 Liquefied undrained shear strength and post earthquake stability analysis 12.6.1 Some general principles 12.6.2 Background to the assessment of the liquefied shear strength Su(LIQ) 12.6.3 Some methods for assessing the strength of liquefied soils in the embankment and foundation 22.214.171.124 "Critical State'' based methods 126.96.36.199 Normalized strength ratio methods 188.8.131.52 Other methods 12.6.4 Some other factors to consider 12.6.5 Recommended approach to assessing the liquefied undrained strength soils of in the embankment and foundation 12.6.6 Methods for assessing the post earthquake strength of non-liquefied soils in the embankment and foundation 184.108.40.206 Saturated potentially liquefiable soils 220.127.116.11 Cyclic softening in clays and plastic silts 18.104.22.168 Compacted plastic and non-plastic soils 12.6.7 Liquefaction potential and limit equilibrium stability analysis 12.6.8 Site investigations requirements and development of geotechnical model of the foundation 12.7 Seismic deformation analysis of embankment dams 12.7.1 Preamble 12.7.2 Performance of embankment dams during earthquakes 12.7.3 The methods available and when to use them 12.7.4 Suggested approach to estimation of deformations 12.7.5 Screening methods 22.214.171.124 USACE method 126.96.36.199 Hynes-Griffin and Franklin (1984) pseudo-static seismic coefficient method 12.7.6 Empirical database methods 188.8.131.52 Swaisgood (1998, 2003) empirical method for estimating crest settlements 184.108.40.206 Pells and Fell empirical method for estimating settlement, damage and cracking 12.7.7 Simplified methods of deformation analysis for dams where liquefaction and significant strain weakening do not occur 220.127.116.11 General principles 18.104.22.168 Makdisi and Seed (1978) method 22.214.171.124 Bray and Travasarou (2007) method 12.7.8 Advanced numerical methods for estimating deformations during and post earthquake for non-liquefied and liquefied conditions 126.96.36.199 Total stress codes 188.8.131.52 Effective stress codes 184.108.40.206 Summary 12.8 Defensive design principles for embankment dams 12.9 Methods for upgrading embankment dams for seismic loads 12.9.1 General approaches 12.9.2 Upgrading of embankment dams not subject to liquefaction 12.9.3 Embankment dams subject to liquefaction 13 Embankment dam details 13.1 Freeboard 13.1.1 Definitions and overall requirements 13.1.2 Examples of freeboard requirements 220.127.116.11 New embankment dams 18.104.22.168 Existing embankment dams 22.214.171.124 Suggested approach for determining freeboard 13.1.3 Estimation of wave run up freeboard for design of small dams and for feasibility and preliminary design 13.1.4 Estimation of wind setup and wave run-up for detailed design 126.96.36.199 Fetch 188.8.131.52 Design wind 184.108.40.206 Wave height 220.127.116.11 Wave length and wave period 18.104.22.168 Wave run-up 22.214.171.124 Wind set-up 13.2 Slope protection 13.2.1 Upstream slope protection 126.96.36.199 General requirements 188.8.131.52 Sizing and layer thickness 184.108.40.206 Selection of design wind speed and acceptable damage 220.127.116.11 Rock quality and quarrying 18.104.22.168 Design of filters under rip-rap 22.214.171.124 Use of soil cement and shotcrete for upstream slope protection 13.2.2 Downstream slope protection 126.96.36.199 General requirements 188.8.131.52 Grass and rockfill cover 13.3 Embankment crest details 13.3.1 Camber 13.3.2 Crest width 13.3.3 Curvature of crest in plan 13.4 Embankment dimensioning and tolerances 13.4.1 Dimensioning 13.4.2 Tolerances 13.5 Conduits through embankments 13.5.1 Piping into the conduit 13.5.2 Piping along and above the conduit 13.5.3 Flow out of the conduit 13.5.4 Conclusions 13.5.5 Recommendations 13.6 Interface between earthfill and concrete structures 13.6.1 Interface between retaining walls and embankment 13.6.2 Interface between concrete gravity dam and embankment 13.7 Flood control structures 13.8 Design of dams for overtopping during construction 13.8.1 General design concepts 13.8.2 Types of steel mesh reinforcement 13.8.3 Design of steel reinforcement 13.9 Design of rip rap for minor overtopping of levees or small dams during floods 13.10 Other overtopping protection methods for embankment dams 14 Specification and quality control of earthfill and rockfill 14.1 Specification of rockfill 14.2 Specification of earthfill 14.3 Specification of filters 14.4 Quality control 14.4.1 General 14.4.2 `Methods,' and `performance' criteria 14.4.3 Quality control 14.4.4 Influence of non technical factors on the quality of embankment dams 14.5 Testing of rockfill 14.5.1 Particle size, density and permeability 14.5.2 Field rolling trials 14.6 Testing of earthfill 14.6.1 Compaction-test methods 14.6.2 Compaction control - some common problems 14.6.3 Compaction control - some other methods 15 Concrete face rockfill dams 15.1 General arrangement and reasons for selecting this type of dam 15.1.1 Historic development of concrete face rockfill dams 15.1.2 General arrangement - modern practice 15.1.3 Site suitability, and advantages of concrete face rockfill dams 15.2 Rockfill zones and their properties 15.2.1 Zone 2D - Transition rockfill 15.2.2 Zones 2E, 3A and 3B - Fine rockfill, rockfill and coarse rockfill 184.108.40.206 General requirements 220.127.116.11 Layer thickness and compaction 18.104.22.168 Use of gravel as rockfill 15.2.3 Effect of rock properties, compaction and addition of water during compaction on modulus of rockfill 15.2.4 Estimation of the modulus of rockfill 22.214.171.124 Estimation of the secant modulus Erc 126.96.36.199 Estimation of the first filling `pseudo modulus' Erf 188.8.131.52 Effect of valley shape 15.2.5 Selection of side slopes and analysis of slope stability 15.3 Concrete face 15.3.1 Plinth 15.3.2 Face slab 184.108.40.206 Face slab thickness 220.127.116.11 Reinforcement 18.104.22.168 Vertical and horizontal joints 15.3.3 Perimetric joint 22.214.171.124 General requirements 126.96.36.199 Water stop details 15.3.4 Crest detail 15.4 Construction aspects 15.4.1 Plinth construction and special details 15.4.2 River diversion 15.4.3 Embankment construction 15.5 Some non-standard design features 15.5.1 Use of dirty rockfill 15.5.2 Dams on erodible foundation 15.5.3 Leaving alluvium in the dam foundation 15.5.4 Plinth gallery 15.5.5 Earthfill cover over the face slab 15.5.6 Spillway over the dam crest 15.6 Observed settlements, and displacements of the face slab, and joints 15.6.1 General behaviour 15.6.2 Post construction crest settlement 15.6.3 Face slab displacements and cracking 15.6.4 Cracks in CFRD dams 15.7 Observed leakage of CFRD 15.7.1 Modern CFRD 15.7.2 Early CFRD and other dams which experienced large leakage 15.8 Framework for assessing the likelihood of failure of CFRD 15.8.1 Overview of approach 15.8.2 Assessment of likelihood of initiation of a concentrated leak 15.8.3 Assessment of the likelihood of continuation of a concentrated leak 15.8.4 Assessment of the likelihood of progression to form a pipe 15.8.5 Assessment of the likelihood of a breach forming 15.8.6 Concluding remarks 15.9 Further reading 16 Concrete gravity dams and their foundations 16.1 Outline of this chapter 16.2 Analysis of the stability for normal operating and flood loads 16.2.1 Design loads 16.2.2 Load combinations 16.2.3 Kinematically feasible failure models 16.2.4 Analysis of stability 16.2.5 Acceptance criteria 16.3 Strength and compressibility of rock foundations 16.3.1 Some general principles 16.3.2 Assessment of rock shear strength 188.8.131.52 General requirements 184.108.40.206 Shear strength of clean discontinuities 220.127.116.11 Shear strength of infilled joints and seams showing evidence of previous displacement 18.104.22.168 Shear strength of thick infilled joints, seams or extremely weathered beds with no previous displacement 22.214.171.124 Shear strength of jointed rock masses with no persistent discontinuities 16.3.3 Tensile strength of rock foundations 16.3.4 Compressibility of jointed rock foundation 16.3.5 Ultimate bearing capacity of rock foundations 16.4 Strength of the concrete in the dam 16.4.1 What is recommended in guidelines 16.4.2 Measured concrete strengths from some USA dams 126.96.36.199 Background to the data 188.8.131.52 Tensile strength of concrete and lift joints 184.108.40.206 Shear strength of concrete 16.5 Strength of the concrete - rock contact 16.6 Uplift in the dam foundation and within the dam 16.6.1 What is recommended in guidelines? 16.6.2 Some additional information on uplift pressures 220.127.116.11 Effects of geological features and deformations on foundation uplift pressures 18.104.22.168 Analysis of EPRI (1992) uplift data 22.214.171.124 Design of drains 126.96.36.199 Hydro-dynamic forces 188.8.131.52 Aprons 184.108.40.206 `Contact' or `box' drains 16.7 Silt load 16.8 Ice load 16.9 The design and analysis of gravity dams for earthquake loading 16.9.1 Introduction 16.9.2 Gravity dams on soil foundations 16.9.3 Gravity dams on rock foundations 220.127.116.11 General 18.104.22.168 The Westergaard pseudo-static method 22.214.171.124 The Fenves-Chopra refined pseudo-static method 126.96.36.199 The US Corps of engineers method 188.8.131.52 Finite Element Method (FEM) 184.108.40.206 Design earthquake input motion 220.127.116.11 Should vertical ground motion be included? 18.104.22.168 Reservoir level variation 22.214.171.124 What do the results of analyses mean? 126.96.36.199 Post-earthquake analyses 188.8.131.52 Dams on rock foundations with potentially deep-seated failure mechanisms 184.108.40.206 Dams on foundations that could be subjected to ground displacement 16.9.4 Concluding remarks 17 Foundation preparation and cleanup for embankment and concrete dams 17.1 General requirements 17.1.1 Embankment dams 17.1.2 Concrete dams 17.1.3 Definition of foundation requirements in geotechnical terms 17.2 General foundation preparation for embankment dams 17.2.1 General foundation under earthfill 220.127.116.11 Rock foundation 18.104.22.168 Soil foundation 17.2.2 General foundation under rockfill 17.2.3 General foundation under horizontal filter drains 17.3 Cutoff foundation for embankment dams 17.3.1 The overall objectives 17.3.2 Cutoff in rock 17.3.3 Cutoff in soil 17.4 Width and batter slopes for cutoff in embankment dams 17.4.1 Cutoff width W 17.4.2 Batter slope 17.4.3 Setting out 17.5 Selection of cutoff foundation criteria for embankment dams 17.6 Slope modification and seam treatment for embankment dams 17.6.1 Slope modification 17.6.2 Seam treatment 17.6.3 Dental concrete, pneumatically applied mortar, and slush concrete 17.6.4 The need for good records of foundation treatment 17.7 Assessment of existing embankment dams 17.8 Foundation preparation for concrete gravity dams on rock foundations 17.8.1 The general requirements 17.8.2 Excavation to expose a suitable rock foundation 17.8.3 Treatment of particular features 17.8.4 Treatment at sites formed by highly stressed rock 18 Foundation grouting 18.1 General concepts of grouting dam foundations 18.2 Grouting design - cement grout 18.2.1 Staging of grouting 18.2.2 The principles of `closure' 18.2.3 The design and quality control of cement grouts 22.214.171.124 The cement and additives used for grouting 126.96.36.199 Water cement ratio 188.8.131.52 Rheological properties of grout 184.108.40.206 High, medium and low mobility grouts 220.127.116.11 Field quality control testing of grouts 18.104.22.168 Grout pressure 22.214.171.124 Recommended closure criteria for embankment and concrete dams 18.2.4 Effect of cement particle size, viscosity, fracture spacing and Lugeon value on the effectiveness of grouting 18.2.5 The effectiveness of a grout curtain in reducing seepage 18.2.6 The depth and lateral extent of grouting 18.2.7 Grout hole position and orientation 1 18.3 Some practical aspects of grouting with cement 18.3.1 Grout holes 18.3.2 Standpipes 18.3.3 Grout caps 18.3.4 Grout mixers, agitator pumps and other equipment 18.3.5 Monitoring of grouting program 18.3.6 Water pressure testing 18.4 Prediction of grout takes 18.5 Durability of cement grout curtains 18.6 Chemical grouts in dam engineering 18.6.1 Types of chemical grouts and their properties 18.6.2 Grout penetrability in soil and rock 18.6.3 Grouting technique 18.6.4 Applications to dam engineering 19 Mine and industrial tailings dams 19.1 General 19.2 Tailings and their properties 19.2.1 What are mine tailings? 19.2.2 Tailings terminology and definitions 19.2.3 Tailings properties 126.96.36.199 General 188.8.131.52 Particle size 184.108.40.206 Mineralogy 220.127.116.11 Dry density and void ratio 18.104.22.168 Permeability 22.214.171.124 Properties of water in tailings 19.3 Methods of tailings discharge and water recovery 19.3.1 Tailings discharge 19.3.2 Cyclones 19.3.3 Sub-aqueous vs sub-aerial deposition 19.3.4 Water Recovery 19.4 Prediction of tailings properties 19.4.1 Beach slopes and slopes below water 19.4.2 Particle sorting 19.4.3 Permeability 19.4.4 Dry density 19.4.5 The prediction of desiccation rates 19.4.6 Drained and undrained shear strength 1 126.96.36.199 Drained shear strength 188.8.131.52 Undrained shear strength 19.5 Methods of construction of tailings dams 19.5.1 General 19.5.2 Construction using tailings 184.108.40.206 Upstream method 220.127.116.11 Downstream method 18.104.22.168 Centreline method 19.5.3 Construction using conventional water dams 19.5.4 Selection of embankment construction method 19.5.5 Control of seepage by tailings placement, blanket drains and under-drains 22.214.171.124 Tailings placement 126.96.36.199 Drainage blankets and under-drains 19.5.6 Some factors affecting the potential for internal erosion and piping of tailings dams 19.5.7 Some factors to consider for seismic design of tailings dams 188.8.131.52 Conventional dams and downstream construction 184.108.40.206 Upstream construction 19.5.8 Storage layout 19.5.9 Other disposal methods 220.127.116.11 Thickened discharge or Robinsky method 18.104.22.168 Co-disposal 22.214.171.124 Paste disposal 126.96.36.199 Belt filtration 188.8.131.52 Disposal into open cut and underground mine workings 184.108.40.206 Discharge into rivers or the sea 19.6 Seepage from tailings dams and its control 19.6.1 General 19.6.2 Principles of seepage flow and estimation 19.6.3 Some common errors in seepage analysis 19.6.4 Seepage control measures 220.127.116.11 Controlled placement of tailings 18.104.22.168 Foundation grouting 22.214.171.124 Foundation cutoffs 126.96.36.199 Clay liners 188.8.131.52 Under-drains 184.108.40.206 Synthetic liners (geomembranes) 220.127.116.11 Geomembrane liners 19.6.5 Seepage collection and dilution measures 18.104.22.168 Toe drains 22.214.171.124 Pump wells 126.96.36.199 Seepage collection and dilution dams 19.6.6 Rehabilitation 188.8.131.52 Long term stability and settlement 184.108.40.206 Erosion control 220.127.116.11 Seepage control 18.104.22.168 Return of area to productive use 20 Monitoring and surveillance of embankment dams 20.1 What is monitoring and surveillance? 20.2 Why undertake monitoring and surveillance? 20.2.1 The objectives 20.2.2 Is it really necessary? 20.2.3 Some additional information on embankment dam failures and incidents 20.2.4 Time for development of internal erosion and piping failure of embankment dams and ease of detection 20.2.5 The ability of monitoring to detect slope instability 20.3 What inspections and monitoring is required? 20.3.1 General principles 20.3.2 Some examples of well instrumented embankment dams 20.3.3 Dam safety inspections 20.4 How is the monitoring done? 20.4.1 General principles 20.4.2 Seepage flow measurement and observation 20.4.3 Surface displacements 20.4.4 Pore pressures 22.214.171.124 Why and where are pore pressures measured? 20.4.5 Pore air and pore water pressure 126.96.36.199 Fluctuations of pore pressure with time and the lag in response of instruments 188.8.131.52 Types of instruments and their characteristics 20.4.6 Should piezometers be installed in the cores of earth and earth and rockfill dams? 20.4.7 Displacements and deformation 184.108.40.206 Vertical displacements and deformation 220.127.116.11 Horizontal displacements and deformations 20.4.8 Thermal monitoring of seepage 18.104.22.168 General 22.214.171.124 Distributed fibre optic temperature sensing 126.96.36.199 Thermotic sensors in stand pipes in the dam 188.8.131.52 Infra-red imaging of the downstream face of the dam and foundations 20.4.9 Use of geophysical methods to detect seepage 184.108.40.206 Self potential 220.127.116.11 Resistivity 18.104.22.168 Other methods References Appendix A: Methods for estimating the probability of failure by internal erosion and piping Subject index
Robin Fell is Emeritus Professor of Civil Engineering at the University of New South Wales, Australia, and also works as a consultant. He has more than 40 years of experience in geotechnical engineering of dams, landslides and civil and mining projects in Australia and Asia. He has worked on over 100 dams worldwide and has been involved in all aspects of planning, site investigation, design and construction of embankment dams. Patrick MacGregor is a Consulting Engineering Geologist with more than 40 years experience in the assessment of geological constraints for major civil engineering projects in a number of countries. He has been involved in dam investigation, design and construction, and particularly worked on hydroelectric developments at all stages from inception to operation. David Stapledon spent many years investigating large dam construction sites in various countries. He was a Professor of Engineering Geology at the University of South Australia (1964 -1993) and worked as a Consultant in Engineering Geology, contributing to major dam projects in Australia, New Zealand and South East Asia. He has more than 50 years of experience and was awarded the John Jaeger Memorial Medal for Contributions to Geomechanics in 1995. Graeme Bell has been a Consulting Dam Engineer since 1962. His role has varied from providing the full technical input, design management and construction advice for new dams to the preparation of complex structural analyses of existing dams. From 1979, he has acted as an independent reviewer on many dam projects, mainly in Australia, but also in several overseas locations. Mark Foster has 20 years of experience in dam engineering and geotechnical engineering. This has involved a wide variety of projects including dam safety reviews, design of dam upgrade projects and dam safety risk assessments for embankment and concrete dams. He has a particular interest in the assessment of piping and internal erosion of embankment dams which was the topic of his doctoral research studies at the University of New South Wales.
Eleven years after the publication of the first edition of the excellent book Geotechnical Engineering of Dams, the geotechnical and dam engineering community can enjoy reading and analyzing the second edition, completely revised, updated, enlarged and enriched. [...] All chapters are almost equally important and interesting for any dam and geotechnical engineer, but I especially like chapters 8 and 9, dealing with internal erosion, piping and filters at embankment dams and in foundation. Apparently, a great experience and original research knowledge of part of the authors of the book is embedded in these thoroughly executed chapters. I cannot also avoid mentioning chapter 12 - Design of embankment dams to withstand earthquakes - in which an up-to-date review and analysis of this sensitive aspect of embankment dam design is given, still under intensive development. Dam builders have always been aware of the fact that dams are firmly bonded to the foundation. But, with this extraordinary book, the bond seems even stronger! I am sure this book will be an unavoidable professional reference and guide in the libraries of all dam and geotechnical engineers. Also, I strongly recommend the book to advanced university students as a textbook, as well as a source of ideas for further research works. Ljubomir Tanchev, Professor on dams and hydraulic structures, University of Skopje, Macedonia This book fills a lacuna in the available comprehensive literature on Geotechnical Engineering of Dams. [...] It covers dimensions not seen in normally available and commonly prescribed textbooks. An intuitive sense of amalgamating both theory and practice is the distinguished and remarkable feature of the book. [...] A very important and useful aspect of the book is that it covers common errors in the five major aspects of safe dams and provides insight in these aspects by dealing with practical problems and case studies. The book very well covers all important geotechnical aspects of dam engineering for civil engineering students at undergraduate as well as at post graduate level and for practitioners. [...] Academicians & practicing engineers will be able to sharpen their knowledge with the help of input provided by the book. The book is useful to civil engineers [...] working in the area of geotechnical dam engineering and ground improvement. Prof. Gautam N. Gandhi, President, Indian Geotechnical Society, New Delhi, Formerly Principal, IDS, Nirma University, India The book is an excellent contribution in the area of dam engineering. Dam Engineering has become an important area in providing efficient infrastructure for water supply, power generation as well as resources generation and conservation. The revision of the previous edition is timely and up to date. [...] In summary, the treatise is comprehensive, up-to-date and needs to be studied by scientists and engineers, organizations, professional bodies, policy makers and builders connected with dam engineering. Prof. G.L. Sivakumar Babu, Chairman, International Technical Committee on Forensic Geotechnical Engineering ISSMGE / Governor, Region 10, American Society of Civil Engineers, USA / Editor-in Chief, Indian Geotechnical Journal, Department of Civil Engineering, Indian Institute of Science, Bangalore, India