TUG - Institute of Hydraulic Engineering and Water Resources Management 1

Transcription

1 Large Dams Design, Construction and Performance Gerald Zenz Graz - University of Technology 1 Dam Structures & Geotechnique Design Construction / Observation Operation / Monitoring Cooperation & Transfer of Know How Improving / Upgrading 2 and Water Resources Management 1

2 Large Dams Design, Construction, Operation and Rehabilitation Gravity Dams System of Load Transfer Design Issues Sliding Stability Example HEPP Birecik Fill and Gravity Dam Structure Double Curved Arch Dams Bearing Behaviour Design Aspects Abutment Stability Example Schlegeis Dam / Austria Example HEPP Tzankov Kamak / Bulgaria Example HEPP Ermenek / Turkey Pumped Storage Scheme Limberg II / Pressure Tunnel Rehabilitation Bottom Outlet of Salza Dam 3 Gravity Type - Dam Structures 4 and Water Resources Management 2

3 Loading Cases Dead Weight Water Loading, Uplift Temperature Silt pressure Ice Loading Wind and Wave Earthquake Loading Operating Earthquake OBE Maximum Credible Earthquake Structural Alterations 5 Design Control Measures Failure Mode Sliding in any plane in the Abutment -In the interface concrete to Rock -In any possible joint -In fault system in the Rock -Tensile- and Compression Usability System Performance -Layout -Material Parameters -Permeability 6 and Water Resources Management 3

4 Uplift Pressure Distribution 7 Earthquake Loading 8 and Water Resources Management 4

5 Required Safety Margin = σ n tan ϕ b + JRC log τ 10 JCS σ n φ b = 29,5 Residual Friction Angle / Laboratory JRC = 8,3 Comparison Publication / Field JCS = 27,2MPa Laboratory Measurements Correlation with Schmidt Hammer 9 Selected Hydro Power Plants in Turkey Muratli Borcka Deriner Ermenek Birecik Karkamis Const. Under Oper. Cons. 10 and Water Resources Management 5

6 Hydro Schemes at the Euphrat Birecik first large BOT Project in Turkey Start of Construction April 1996 Construction Time 66 Month River Diversion June 1999 Start of Impounding October 2000 Commercial Operation Since Oct Hydro Electric Powerplant - Birecik Fill Dam (2000m) Clay Core Height 62,5m Concrete Dam (500m) Gravity Dam Intake Structure Power House 6x112MW Francis Design Discharge 6x317m 3 /s ~ 1900m 3 /s Spillway 10 Sections 12,5m 17500m 3 /sec Design Flood 12 and Water Resources Management 6

7 Dam Cross Section 13 Dammquerschnitt Sliding Stability Earthquake Safety Soil Liquefaction Seepage Analysis Rapid Drawdown 14 and Water Resources Management 7

8 Excavation Spillway - Intake Geotechnical Investigations -Site Mapping -Drilling Campaign -Laboratory & In Situ - Tests -Geophysical Investigation 15 Joint System Clay Filled φ clay = 22,4 Clay Friction Angle / Laboratory 16 and Water Resources Management 8

9 Spillway - Section 17 Intake Section 18 and Water Resources Management 9

10 Additional Excavation Spillway - Intake 19 Additional Excavation 20 and Water Resources Management 10

11 Operation - Monitoring of Performance HPP Birecik Design Flow 1900m 3 /s Hydraulic Head 44m Capacity 672MW 6 Francis Units Annual Production 2500GWh Entire Length 2510m Reservoir Volume 1200Mio m 3 21 Operation Monitoring Performance Geodetic Measurements Seepage / Uplift Displacements Plump Line / Extensometers / Joint Meters Operation Reservoir Water Level / Downstream Water Level / Temperatures 22 and Water Resources Management 11

12 Uplift Pressure Measurements 23 Radial Deformation Measurements - Intake 24 and Water Resources Management 12

13 Arch Dam Bearing Behavior Foundation Uplift Seepage 25 Schlegeis Dam Crest length Height Thickness 725m 131m 34m / 9m Total Concrete Volume m 3 26 and Water Resources Management 13

14 Dam Excavation 27 Method of Construction Individual Columns Maximum Height Difference Placing Temperature Joint Grouting Monolithic Arch Structure Loading Conditions 28 and Water Resources Management 14

15 Method Dependent Results Influence Mesh Size Deformation Behavior 29 Situation at Central Cross Section 30 and Water Resources Management 15

16 Finite Element Cross Section Abutment Forces 31 Forces Along the abutment Dead Weight & Water Load & Uplift Dead Weight Dead Weight & Water Load 32 and Water Resources Management 16

17 Abutment Block Sliding Analysis Resultant Forces Vertical Horizontal Sliding Safety 33 Dynamic Analyses 34 and Water Resources Management 17

18 DYNAMIC BEHAVIOUR Measured Eigenfrequencies and Mode Shapes Water Level 7m below crest Measured Calculated 1,92 1,81 2,05 1,86 2,50 2,38 35 Added Mass Versus Fluid Structure Interaction 1782 müa; Stauziel z b H müa 36 and Water Resources Management 18

19 Added Mass Versus - FSI 37 Abutment Stability Failure Mode Sliding in any plane in the Abutment -In the interface concrete to Rock -In any possible joint / fault system in the Rock Compression / Tension Usability System Performance -Layout -Material Parameters -Permeability / Uplift Water Pressure 38 and Water Resources Management 19

20 Arch Dam Behavior ICOLD Benchmark measurements provided linear + nonlinear benchmark ICOLD Dam Analysis and Water Resources Management 20

21 Tsankov Kamak - Dam Concreting under Progress Double Curved Arch Dam Arch Dam Height 125 m Crest Length 457 m Concrete Volume m³ Reservoir: Max. Flood Level m Max. Op. Level m Min. Op. Level m Total Storage Volume 111 Mio.m³ Active Storage Volume 41 Mio.m³ 42 and Water Resources Management 21

22 Bottom Outlet 2 steel pipes through Dam Length 37 m Diameter 1.3 m Closing Device: 2 slide gates Spillway 4 Dam Crest Overflow Sections Radial Gates 4x 8.0/8.0 m Stilling Basin 106/66 m Capacity 1500 m³/s 43 Geotechnical Investigations 44 and Water Resources Management 22

23 45 Abutment Forces 46 and Water Resources Management 23

24 Horizontal - Geological Section 47 Grout- and Drainage Curtain 48 and Water Resources Management 24

25 Model for Dam Abutment Stability Calculation 49 Conservative Model - Keyblock Analysis Water Pressure 50 and Water Resources Management 25

26 Temperature Distribution End of Construction 51 Earthquake Excitation MCE - 0,41g for 10000year return period 52 and Water Resources Management 26

27 Model of Structure and Water Nonlinear Dynamic Analysis Joint at the Abutment Block Joints Construction Joints Implicit Direct Time Integration Massless Rock Reservoir Modeled FSI analysis Acceleration time history 53 Nonlinear Dynamic Analyses 54 and Water Resources Management 27

28 August 2008 Quality Assurance During Execution of Construction Rock Abutment (Geological Monitoring) Concrete Production / Surface / Core Grouting Temperature Distribution 55 August and Water Resources Management 28

29 August HPP Ermenek Arch Dam Design and Construction Reservoir Volume: 4600 Mio m 3 Gross Height: 361 m Capacity: 300 MW Annual Production: 1014 GWh Investment: 540 Mio Eur Concrete Volume: m 3 Dam Height: 218 m Crest Length: 120 m Dam Thickness: Crest 7m Base 25m 58 and Water Resources Management 29

30 59 Double curved Arch 218m Power House 300 MW 1,000 GWh Pressure Tunnel Length 8km Diameter 5.6m Grout Curtain m2 Erik Diversion Pressure Tunnel 60 and Water Resources Management 30

31 Pressure Tunnel Tunnel Boring Maschine Excav. Diameter 6,7m Geology Limestone Karst Flysh Water intrusion 61 Tunnel - Durchschlag Ausbruchsfortschritt Max. Tagesleistung 62m/Tag Max.Monatsleistung 1004m / Monat 62 and Water Resources Management 31

32 Tunnel Durchschlag 8100m Gesamtlänge Beginn 26 th July 2003 Durchschlag 2 nd April Power Station Switch Yard Power House Ermenek NQ ~15m 3 /s MQ ~43m 3 /s 64 and Water Resources Management 32

33 Switcht Yard Stability Design Reliefe Wells 65 Valve Chamber Surge Tank Erik Pressure Tunnel Erik Surge Tank Surge Tank Access Tunnel Vertical Pressure Shaft Ermenek Surge Tank Pressure Tunnel 8,1km Inclined Shaft 1km Erik Power Cavern Power Cavern Access Tunnel Valve Chamber Ermenek Pressure Tunnel Surge Tank Diameter 10m Height ~135m Access Tunnel Inclined Pressure Shaft 66 and Water Resources Management 33

34 Erik Diversion Ermenek Surge Tank Erik Addit Surge Tank - Ermenek 67 Dam Construction Site - Downstream Dam Left Abutment Galleries GL2 / GL3 68 and Water Resources Management 34

35 Canyon Depth 200m Broad 10 bis 25m Vertical partly Steep valley 69 Gorge 70 and Water Resources Management 35

36 Ermenek - Double Curved Arch Dam 71 Abutment Forces Block Winter and Summer loading condition Direction and Magnitude are calculated 72 and Water Resources Management 36

37 Hydration Heat Development C E,FA Specific heat c 0.92 kj/(kg K) Conductivity k 11.2 kj/(m h K) = kj/(m d K) Cement content z 210 kg/m³ Weight density ρ 2450 kg/m³ Hydration heat H 343 kj/kg adiabatic conditions concrete temperature [ C] analysis results 5.00 theoretic value time [d] and Water Resources Management 37

38 Concrete Temperature Distribution End of Construction April 2010 Concrete Temperature 17 C Partial impounding requires postcooling 75 Instrumentation Main Dam Cross Section 76 and Water Resources Management 38

39 Instrumentation Main Dam Horizontal Cross Section 77 Rock Abutment Right Bank 78 and Water Resources Management 39

40 How a Geologist Sees the Right Bank 79 Detailed Investigation at Right Abutment 80 and Water Resources Management 40

41 Abutment Stability = σ n tan ϕ b + JRC log τ 10 Possible Sliding Planes RJ5e and RJ5g RJ5g (320/80) φ i = 37 + f(jrc) c min = 0,2MPa JCS σ n 81 Dam Excavation Right Bank - D/S Key Blocks Rj5g 320/80 Rj5a285/65 G20 285/65 Dam Foot Print Rj5e 354/68 First Blasting El 695 DS Cave G24 Second Blasting El 685 US RJ3a 64/80 82 and Water Resources Management 41

42 D E S I G N E X E C U T I O N 83 Limited Working area at the berms 84 and Water Resources Management 42

43 Anchor drilling from the basket 85 Adaptation of Appropriate Blasting 86 and Water Resources Management 43

44 Blasting Result 87 Measurement During Execution Observational Method 88 and Water Resources Management 44

45 89 90 and Water Resources Management 45

46 Dam Concreting under Progress Drainage Curtain Grout Curtain Hydraulic Head 23bar 91 Status of Work September and Water Resources Management 46

47 Status of Work Elevation about 540m a.s.l Start of Impounding at ~610m a.s.l Partial Impounding Initial Large Increase in Hydraulic Head Grouting of Block Joints Temperature Distribution and Water Resources Management 47