Dams and Appurtenant Hydraulic Structures

PREFACE XV

PART ONE: Dams and appurtenant hydraulic structures – general

1 UTILIZATION OF WATER RESOURCES BY MEANS OF HYDRAULIC STRUCTURES 3

• 1.1 Introduction 3
• 1.2 Hydraulic structures (definition, classification) 6
• 1.3 General features of hydraulic structures 7
• 1.4 Intent of dams. Elements of a dam and a reservoir 16
• 1.5 Short review of the historical development of hydraulic structures 18

2 FOUNDATIONS OF DAMS 19

• 2.1 On foundations for hydraulic structures in general 19
• 2.2 Requirements for the foundation 22
• 2.3 Investigation works regarding dam foundations 30
• 2.4 Improvement of foundations 32

3 SEEPAGE THROUGH DAMS 42

• 3.1 Action of seepage flow 42
• 3.2 Mechanical action of seepage flow on the earth skeleton 43
• 3.3 Seepage resistance of earth foundations and structures 46
• 3.4 Theoretical aspects of seepage 47
• 3.5 Practical solution of the problem of seepage 53
• 3.6 Seepage in anisotropic soil conditions 56
• 3.7 Seepage in nonhomogenous soil conditions 59
• 3.8 Seepage of water through rock foundations 60
• 3.9 Lateral seepage 63
• 3.10 Seepage through the body of concrete dams 64

4 FORCES AND LOADINGS ON DAMS 66

• 4.1 On forces and loadings on dams in general 66
• 4.2 Forces from hydrostatic and hydrodynamic pressure 68
• 4.3 Influence of cavitation and aeration on hydraulic structures 70
• 4.4 Influence from waves 72
• 4.5 Influence of ice and water sediment 78
• 4.6 Seismic forces 80
• 4.7 Temperature effects 84
• 4.7.1 Temperature effects on embankment dams 84
• 4.7.2 Temperature effects on concrete structures 86

5 DESIGNING HYDRAULIC STRUCTURES 87

• 5.1 Basic stages in the process of the creation and use of hydraulic structures 87
• 5.2 Investigation for design and construction of hydraulic structures 88
• 5.3 Contents of the hydraulic design and design phases 91
• 5.4 Project management and the role of legislation 96

PART TWO: Embankment dams

6 EMBANKMENT DAMS – GENERAL 101

• 6.1 Introduction. Terminology. Classification 101
• 6.2 Historical development of embankment dams 105
• 6.3 Dimensions of the basic elements of embankment dams 108
• 6.4 Choice of the dam site 113
• 6.5 Materials for construction of embankment dams 115
• 6.6 Choice of type of embankment dam 120
• 6.7 Tailings dams 123

7 SEEPAGE THROUGH EMBANKMENT DAMS 127

• 7.1 Kinds of seepage through the embankment dam body 127
• 7.2 Seepage line and hydrodynamic net in embankment dams 129
• 7.3 Measures against the harmful effect of seepage 134
• 7.3.1 Action against local seepage rising 134
• 7.3.2 Action against external suffosion 135
• 7.4 Calculations of the casual seepage strength of earthfill dams 141

8 STATIC STABILITY OF EMBANKMENT DAMS 144

• 8.1 Introduction 144
• 8.2 Classical methods 144
• 8.2.1 Method of Slices 145
• 8.2.2 Wedge Method 149
• 8.2.3 States in which stability of embankment dams is examined 150
• 8.2.4 Stability of rockfill dams 156
• 8.3 Contemporary methods 157
• 8.3.1 Application of the Finite Elements Method 157
• 8.3.2 Specific properties of the application of the Finite Element Method (FEM) for analysis of embankment dams 161
• 8.3.3 Choice of constitutive law 161
• 8.3.4 Simulation for dam construction in layers 170
• 8.3.5 Simulation for filling the reservoir and the effect of water 173
• 8.3.6 Simulation of behaviour at the interfaces of different materials 181
• 8.3.7 Analysis of consolidation 186
• 8.3.8 Creep of materials in the body of embankment dams 192
• 8.3.9 Three-dimensional analysis 195

9 DYNAMIC STABILITY OF EMBANKMENT DAMS 197

• 9.1 Effect of earthquakes on embankment dams 197
• 9.2 Assessment of design earthquake 199
• 9.2.1 Strength, attenuation and amplification of earthquakes 199
• 9.2.2 Design Earthquake 203
• 9.3 Liquefaction 205
• 9.4 Analysis of stability and deformations in embankment dams induced by earthquakes 207
• 9.4.1 Pseudo-Static Method 208
• 9.4.2 Pseudo-static methods with a non-uniform coefficient of acceleration 209
• 9.4.3 Equivalent linear method 215
• 9.4.4 Pure nonlinear method 216

10 EARTHFILL DAMS 221

• 10.1 Classification and construction of earthfill dams 221
• 10.2 Structural details for earthfill dams 222
• 10.2.1 Slope protection. 223
• 10.2.2 Water-impermeable elements 228
• 10.2.3 Drainages 234
• 10.3 Preparation of the foundation and the joint between earthfill dams and the foundation 243
• 10.3.1 Preparation of the general foundation 243
• 10.3.2 Preparation of the foundation when using a dam cutoff trench 244
• 10.3.3 Joint of the earthfill dam and the foundation 244

11 EARTH-ROCK DAMS 249

• 11.1 Construction of earth-rock dams 249
• 11.2 Earth-rock dams with vertical core 252
• 11.3 Earth-rock dams with a sloping core 255
• 11.4 Earth-rock dams of "soft" rocks 261
• 11.5 Fissures in the core of earth-rock dams 263
• 11.5.1 Kinds of fissures and causes for their occurrence 263
• 11.5.2 Measures for preventing the occurrence of fissures 266
• 11.6 Designing earth-rock dams in seismically active areas 273

12 ROCKFILL DAMS WITH REINFORCED CONCRETE FACING 275

• 12.1 Definition, field of application and construction 275
• 12.2 Modern dams with reinforced concrete facing 281
• 12.3 Joints for reinforced concrete facings 290
• 12.4 Construction of reinforced concrete facings 295
• 12.5 Examples of modern dams with reinforced concrete facing 297

13 ROCKFILL DAMS WITH ASPHALTIC CONCRETE AND OTHER TYPES OF FACINGS 303

• 13.1 Rockfill dams with asphaltic concrete facing 303
• 13.1.1 General characteristics 303
• 13.1.2 Composition and characteristics of hydraulic asphaltic concrete 304
• 13.1.3 Construction of the asphaltic concrete facings 307
• 13.1.4 Joint of the lining with a gallery or concrete cutoff in dam’s toe 312
• 13.1.5 Joint of the facing with dam’s crest. 317
• 13.2 Rockfill dams with steel facing 318
• 13.3 Rockfill dams with facing of geomembrane 320

14 ROCKFILL DAMS WITH DIAPHRAGM WALL 327

• 14.1 Rockfill dams with asphaltic concrete diaphragm wall 327
• 14.1.1 Function, conditions of work and materials 327
• 14.1.2 Structure of the asphaltic concrete diaphragm walls. 329
• 14.1.3 Joint of diaphragm wall with the foundation and lateral concrete structures 336
• 14.2 Other types of diaphragm walls 340
• 14.2.1 Concrete diaphragm walls 340
• 14.2.2 Grout and plastic diaphragm walls 345
• 14.3 Stability of earth-rock dams with diaphragm wall 346

15 MONITORING AND SURVEILLANCE OF EMBANKMENT DAMS 351

• 15.1 Task and purpose of monitoring 351
• 15.2 Monitoring of pore pressure and seepage 352
• 15.2.1 Hydraulic piezometers. 352
• 15.2.2 Electric piezometers 356
• 15.2.3 Monitoring of seepage. 357
• 15.3 Monitoring of displacements 358
• 15.3.1 Measurement of displacements at the surface of the dam 358
• 15.3.2 Measuring displacements in the interior of the dam 359
• 15.4 Measurements of stresses 367
• 15.5 Seismic measurements 368
• 15.6 General principles on the selection and positioning layout of measuring instruments 369

PART THREE: Concrete dams

16 GRAVITY DAMS ON ROCK FOUNDATIONS 375

• 16.1 On gravity dams in general 375
• 16.2 Mass concrete for dams 376
• 16.2.1 General 376
• 16.2.2 Constituent elements of mass concrete 377
• 16.2.3 Parameters of concrete mixture 378
• 16.2.4 Fabrication and placing of concrete 379
• 16.3 Cross-section of gravity dams 379
• 16.3.1 On the cross-section in general 379
• 16.3.2 Theoretical cross-section 381
• 16.3.3 Practical cross-section 383
• 16.4 Dimensioning of concrete gravity dams 386
• 16.4.1 Elementary methods 387
• 16.4.2 Modern methods 388
• 16.5 Determination of stresses 391
• 16.5.1 Determination of stresses by the gravitational method 391
• 16.5.2 Calculation of stresses by using the theory of elasticity 394
• 16.5.3 Influence of temperature changes, shrinkage and expansion of concrete on stresses in dams 396
• 16.5.4 Permissible stresses and cracks 398
• 16.6 General structural features of gravity dams 398
• 16.7 Stability of gravity dams on rock foundation 409
• 16.7.1 Dam sliding and shearing across foundation 410
• 16.8 Hollow gravity dams 414

17 GRAVITY DAMS ON SOIL FOUNDATION 417

• 17.1 Fundamentals of gravity dams on soil foundation 417
• 17.2 Schemes for the underground contour of the dam 419
• 17.3 Determination of basic dimensions of underground contour 421
• 17.4 Construction of elements of the underground contour 423
• 17.5 Construction of dam’s body 427
• 17.6 Dimensioning and stability of gravity dams on soil foundation 435

18 ROLLER-COMPACTED CONCRETE GRAVITY DAMS 439

• 18.1 Introduction 439
• 18.2 Characteristics of roller-compacted concrete 441
• 18.3 Types of roller-compacted concrete 443
• 18.4 Trends in development of dams made of roller-compacted concrete 444
• 18.5 Improving the water-impermeability of dams made of roller-compacted concrete 446
• 18.6 Cost of dams made of roller-compacted concrete 448
• 18.7 Examples of dams made of roller-compacted concrete 450
• 18.8 Particularities of high dams of roller-compacted concrete 467

19 BUTTRESS DAMS 469

• 19.1 Definition, classification and general conceptions 469
• 19.2 Massive-head buttress dams 471
• 19.3 Flat-slab buttress dams 477
• 19.4 Multiple-arch buttress dams 482
• 19.5 Conditions for application of buttress dams 491

20 ARCH DAMS 493

• 20.1 In general on arch dams. Classification 493
• 20.2 Development of arch dams through the centuries 496
• 20.3 Methods of designing of arch dams 501
• 20.3.1 Basic Design 501
• 20.3.2 Arch dams with double curvature 508
• 20.3.3 Form of arches in plan and adaptation to ground conditions 516
• 20.4 Structural details of arch dams 520
• 20.5 Static analysis of arch dams 525
• 20.5.1 Method of independent arches. 526
• 20.5.2 Method of central cantilever 530
• 20.5.3 The Trial-Load Method 533
• 20.5.4 The Finite Element Method 534
• 20.5.5 The Experimental Method 535

21 DYNAMIC STABILITY OF CONCRETE DAMS 538

• 21.1 Earthquake effects on concrete dams 538
• 21.2 Methods for dynamic analysis of concrete dams 539
• 21.2.1 Linear analysis and response of the structure 541
• 21.2.2 Nonlinear analysis and the response of the dam 542
• 21.3 knowledge gained from practice and experiments 545

22 MONITORING AND SURVEILLANCE OF CONCRETE DAMS 548

• 22.1 On monitoring, surveillance and instrumentation of concrete dams in general 548
• 22.2 Monitoring by precise survey methods 548
• 22.3 Surveillance with embedded instruments 552
• 22.4 Automatization and computerization of monitoring 557

PART FOUR: Hydromechanical equipment and appurtenant

hydraulic structures

23 ON MECHANICAL EQUIPMENT AND APPURTENANT HYDRAULIC STRUCTURES IN GENERAL 563

• 23.1 On hydromechanical equipment in general 563
• 23.1.1 Introduction 563
• 23.1.2 Classification of gates and valves 563
• 23.1.3 Forces acting on gates and valves 564
• 23.2 Mechanisms for lifting and lowering of the gates and valves. Service bridges 565
• 23.3 Installation and service of gates and valves 567
• 23.4 Appurtenant hydraulic structures 569
• 23.4.1 Definition, function and capacity 569
• 23.4.2 Classification of spillways and bottom outlets 571
• 23.5 Evacuation of overflowing waters via a chute spillway 573
• 23.6 Energy dissipation of the spillway jet 577
• 23.7 Selection of type of spillway structure 585

24 SURFACE (CREST) GATES 587

• 24.1 Basic schemes of surface (crest) gates 587
• 24.2 Surface (crest) gates transferring water pressure to side walls or piers 590
• 24.2.1 Ordinary plain metal gates 590
• 24.2.2 Special plain gates 595
• 24.2.3 Stop-log gates. 597
• 24.2.4 Radial gates 597
• 24.2.5 Roller gates 603
• 24.3 Surface (crest) gates transferring the waterpressure to the gate sill 606
• 24.3.1 Sector (drum) gates 606
• 24.3.2 Flap gates 609
• 24.3.3 Bear-trap gates 610
• 24.3.4 Inflatable gates 612

25 HIGH-HEAD GATES AND VALVES 613

• 25.1 General characteristics. Classification 613
• 25.2 High-head gates transferring pressure to the structure directly through their supports 615
• 25.2.1 Plain high-head gates 615
• 25.2.2 Radial (taintor) high-head gates 619
• 25.2.3 Diaphragm gate 623
• 25.3 Valves transferring the pressure through the shell encasing the valve 624
• 25.3.1 Waterworks valves type 624
• 25.3.2 Disc-like or butterfly valves 626
• 25.3.3 Cone dispersion valve 627
• 25.3.4 Needle valves and spherical valves 628
• 25.4 Cylindrical balanced high-head valves 629

26 SPILLWAYS PASSING THROUGH THE DAM’S BODY 631

• 26.1 Crest spillways 631
• 26.2 High-head spillway structures 639

27 SPILLWAYS OUTSIDE THE DAM’S BODY 647

• 27.1 Frontal (ogee) spillway structure 647
• 27.2 Side-channel spillway 656
• 27.3 Shaft (morning glory) spillway 663
• 27.4 Siphon spillways 675

28 BOTTOM OUTLET WORKS 679

• 28.1 Basic assumptions on designing bottom outlet works 679
• 28.2 Bottom outlet works in concrete dams 680
• 28.3 Bottom outlet works in embankment dams 682

29 SPECIAL HYDRAULIC STRUCTURES 691

• 29.1 Transport structures 691
• 29.2 Hydraulic structures for the admission and protection of fish 696

30 RIVER DIVERSION DURING THE CONSTRUCTION OF THE HYDRAULIC SCHEME 703

• 30.1 On river diversion during the construction of dams and appurtenant hydraulic structures in general 703
• 30.2 Construction of the structures without river diversion from the parent river channel 704
• 30.2.1 Method with damming of the construction (foundation) pit 704
• 30.2.2 Method without damming of the construction pit 708
• 30.3 Construction of the structures with river diversion from the river channel 710

PART FIVE: Hydraulic schemes

31 COMPOSING OF STRUCTURES IN RIVER HYDRAULIC SCHEMES 715

• 31.1 Definition and classification of hydraulic schemes 715
• 31.2 General conditions and principles for composing hydraulic schemes 716
• 31.3 Characteristics of river hydraulic schemes for different water economy branches 717
• 31.4 Aesthetic shaping of hydraulic schemes 720
• 31.5 River hydraulic schemes without pressure head 723
• 31.6 Low-head hydraulic schemes 724
• 31.7 Medium-head river hydraulic schemes 725

32 HIGH-HEAD RIVER HYDRAULIC SCHEME 729

• 32.1 High-head river hydraulic schemes on mountain rivers (Type I) 729
• 32.2 High-head hydraulic schemes on middle and low parts of rivers 742
• 32.3 Pumped-storage hydraulic scheme 747

33 RESERVOIRS 751

• 33.1 Introduction 751
• 33.2 Formation and safety of reservoirs 752
• 33.2.1 Stability of reservoir banks 752
• 33.2.2 Water-impermeability of the reservoir 756
• 33.2.3 Seismicity of the ground in the zone of the reservoir 759
• 33.2.4 Water absorption of the ground in the zone of the reservoir 761
• 33.2.5 Evaporation 761
• 33.2.6 Sediment accumulation 762
• 33.3 Resettlement of population and relocation of structures 765
• 33.4 Sports and recreational facilities 766

34 NEGATIVE EFFECTS OF HYDRAULIC SCHEMES AND ENVIRONMENTAL PROTECTION 769

• 34.1 Types of negative effects on the environment 769
• 34.1.1 Changing the land into the area of the reservoir 770
• 34.1.2 Change of the flow downstream of the dam 771
• 34.1.3 Damming the migration paths of fish and wild animals 774
• 34.1.4 Change in the surrounding landscape and the microclimate 774
• 34.2 Social and ecological monitoring 776
• 34.3 Environmental protection – selection of a solution with minimum negative effects on the environment 777

35 RESTORATION AND RECONSTRUCTION OF HYDRAULIC SCHEMES 781

• 35.1 Need for restoration and reconstruction 781
• 35.2 Restoration of dams and hydraulic schemes 782
• 35.3 Reconstruction of hydraulic schemes 789

REFERENCES 797

SUBJECT INDEX 817

INDEX OF DAMS 815