Chanson H.“Embankment dam spillways and energy dissipators”
Transcript of Chanson H.“Embankment dam spillways and energy dissipators”
![Page 1: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/1.jpg)
Embankment dam spillways and energy dissipators
by Prof. Hubert CHANSONThe University of Queensland, School of Civil Engineering, Brisbane QLD 4072,
Australia, E-mail: [email protected]
Clermont MEL weir in 1993
Glashutte dam, 22 Aug. 2002
![Page 2: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/2.jpg)
Spillway Designs for Embankment Overtopping System and Earth Dams
CHANSON, H. (2014). "Embankment Dam Spillways and Energy Dissipators." in "Labyrinth and Piano Key Weirs II - PKW 2013." Proceedings of 2nd International Workshop on Labyrinth and Piano Key Weirs -PKW 2013, 20-22 Nov., Paris-Chatou, France, CRC Press, pp. 23-37 (ISBN 978-1-138-00085-8).
Introduction
Embankment failure & breach development
Minimum Energy Loss weirs
Embankment overflow stepped spillways
Precast concrete blocks
Gabions & Reno mattresses
Design considerations
![Page 3: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/3.jpg)
Introduction
Embankment = earthfill structures
ApplicationsDamsRiver training / Flood protectionCoastal protections
Tsunami barrierStorm surge barrier
Natural lakes & Landslide damsMan-made flooding (during wars)
Kyoto, Japan
Sorpe dam, Germany
New Orleans, USA in 2005 (Hurricane Katrina)
![Page 4: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/4.jpg)
EmbankmentsEarthfill structures � Erodible systems when overtoppedLevees, Dykes
![Page 5: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/5.jpg)
Dale Dyke dam (UK)Construction: 1863Failure: 11 March 1864(piping, poor construction)150 lives lost
![Page 6: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/6.jpg)
South Fork dam (USA)Construction: 1838-1853Failure: 31 May 1889(spillway capacity
& construction)2,209 lives lost
![Page 7: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/7.jpg)
Lake Ha! Ha! (Canada)Failure: July 1996(spillway capacity)
![Page 8: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/8.jpg)
Opuha Dam Failure on 5 February 1997
Opuha dam (NZ)Construction: 1996-1999Failure: 5 February 1997(outlet capacity)
![Page 9: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/9.jpg)
Glashutte dam (Germany)Construction: 1953Failure: 12 August 2002(spillway capacity)
![Page 10: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/10.jpg)
Downstream flooding and damageImages courtesy of Dr Bornschein
![Page 11: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/11.jpg)
Embankment failure & breach development
Relatively slow failure processTeton dam (USA, 100 m high) 12 h to drain reservoir (1976)
Zeyzoun dam (Syria) breach opening = 3 ½ h (2002)
Glashutte dam (Germany) 4 hours overtopping +breach opening = 30 min (2002)
Zeyzoun Dam Failure on 4 June 2002
Embankment failure = dam break but ….
![Page 12: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/12.jpg)
Embankment breach development & inlet shape
Sequence of 8 shots within 20 s – Non-cohesive embankment overtopping model
![Page 13: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/13.jpg)
![Page 14: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/14.jpg)
Natural scour = similarity with MEL inlet(McKAY 1970, CHANSON 2003 JHE)
Merriespruit tailings dam failure in 1994 (Courtesy of Pr A. FOURIE)
Saaiplaas tailings failure in 1993
Island of Capri canal
![Page 15: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/15.jpg)
CHANSON, H. (2004). "Overtopping Breaching of Noncohesive Homogeneous Embankments. Discussion." Journal of Hydraulic Engineering, ASCE, Vol. 130, No. 4, pp. 371-374.CHANSON, H. (2005). "The 1786 Earthquake-Triggered Landslide Dam and Subsequent Dam-Break Flood on the DaduRiver, Southwestern China. Comment." Geomorphology, Vol. 71, pp.437-440.
Analogy with Minimum Energy Loss (MEL) culvert inlet
MEL culvert at Redcliffe (Australia)
![Page 16: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/16.jpg)
Brazil
Irago peninsula, Japan
Crotty dam, Australia, 1991
Brushes Clough dam, UK in 1993
Choctaw 8A auxiliary spillway (USA) in 2002
Overflow protection systemsReinforced grassMacro-roughness elementsMinimum Energy Loss weir & spillwayConcrete stepped spillwayPrecast concrete blocksGabion (& Reno mattress) structures
![Page 17: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/17.jpg)
Overtopping protection - Minimum Energy Loss weirs
Developments in 1950s in Queensland (Australia)by late Prof Gordon McKay (1913-1989)
Developed to pass large flood flows with minimum affluxin tropical catchments with very-flat bed slope
Chinchilla MEL weir (1973), Q = 850 m3/s, zero afflux
![Page 18: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/18.jpg)
A
A
Earthfill
Concreteslab
Bank top
Section AA
Chinchilla MEL weir (1973), Qdes = 850 m3/s, zero afflux,ICOLD register listed
View from downstream(400 m3/s)
U/s water level
D/s water level
Basic design featuresSmooth flow contraction towards the crestCritical flow conditions at crestConverging chute wallsEnergy dissipation in channel centreline
![Page 19: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/19.jpg)
Clermont weir (1962/63), Qdes = 850 m3/s
![Page 20: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/20.jpg)
MEL spillway inlet designsSwanbank power house (1965)Lake Kurwongbah (850 m3/s, 1958-69)
MEL inlet design allowed extra 0.457 m of water storage
Lake Kurwongbah, Q = 850 m3/s
Swanbank
![Page 21: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/21.jpg)
Prototype experienceOperation for more than 60 years (incl. Q > design flow)
Soundness of design + Little maintenance
There is no better proof of design soundness than successfulprototype experience
Key issue: expert design (Hydraulics expert & Physical modelling)
Major structures1- Sandy Creek MEL weir (Clermont)
1962/63, 850 m3/s, zero afflux2- Chinchilla MEL weir
1973, 860 m3/s, zero affluxlarge dam with international exposure (ICOLD)
3- Lake Kurwongbah (850 m3/s, 1958-69)MEL inlet design allowed extra 0.457 m of water storage
CHANSON, H. (2003). "Minimum Energy Loss Structures in Australia : Historical Development and Experience." Proc. 12th Nat. Eng. Heritage Conf., IEAust., Toowoomba Qld, Australia, N. Sheridan Ed., pp. 22-28 (ISBN 0-646-42775-X).
![Page 22: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/22.jpg)
Embankment overflow concrete stepped spillwaysChoctaw 8A auxiliary spillway in 2002
Salado Creek Dam Site 15R
Developments during 1990s
Numerous applications
Secondary & primary spillways
![Page 23: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/23.jpg)
RCC stepped spillway for a detention basin in west Las Vegas (USACE)
Tongue river dam (USA, 1997)
Ashton dam embankment overflow (USA,1989-1992) : h = 0.6 m, l = 0.9 m, Qmax = 690 m3/s (PMF)
![Page 24: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/24.jpg)
Opuha dam (NZ, 1995-1999) H = 50 m
Melton dam (Australia, 1916/1990s) Q ~ 2,800 m3/s (secondary spillway)
![Page 25: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/25.jpg)
ConstructionConcrete layers (RCC/rollcrete suitability)
Protection layer (in some cases)
Drainage layer beneath steps
Supplemented by drainage holes
Overflow hydraulicsAdequate discharge capacity
Skimming flow regime (Design flow)
Downstream dissipator
![Page 26: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/26.jpg)
Embankment with precast concrete block stepped spillways
Kolymia (or Kolyma) (Courtesy of Prof. Yuri PRAVDIVETS)
Sosnovsky dam (Photograph by Prof. Yuri PRAVDIVETS)Farm dam, 1978. H = 11 m. qw = 3.3 m2/s, So = 0.167. B = 12 m
Russian design under the leadership of P.I. GORDIENKO
Overlapping precast concrete bocks
Primary spillway applications
Klinbeldin
![Page 27: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/27.jpg)
Brushes Clough dam spillway (UK,1859-1991)- wedge shaped concrete blocks (120 kg each)- Chute slope : 18.4�, h = 0.19 m- Inclined downward steps (-5.6�)- Trapezoidal cross-section
(2-m bottom width, 1V:2H sideslope)- Design flow : 3.66 m3/s, Hdam = 26 m- Field tests in 1993
![Page 28: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/28.jpg)
Prototype experiencesSolid record (qw up to 60 m2/s)
High construction standards requiredImportance of drainage layer
Flexibility of spillway channel bed
Hydraulics considerations
* Skimming flow operation
* Straight prismatic cross-sectional channel
* Downstream stilling structure
Bolshevik farm dam (1980), H = 11.5 m. qw = 3.3 m2/s, So = 0.12-0.2, B = 12 m
Volymia experimental earth dam (H=20 m) in the Magadan region (Siberia)
![Page 29: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/29.jpg)
Gabion & Reno mattress protection
Duralie, NSW (Australia)Robina, QLD (Australia)
Porous materialno uplift pressureinteractions between seepage& overflow
Flexible stepped constructiondifferential settlement
Stacked vs lined placementGabion stepped chute
Limited lifetime (5-10 y)gabion resistance to damage by sediments and debris
![Page 30: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/30.jpg)
Design considerations – Overflow protection (all systems)ConstructionStability of earthfill structure is essential� Good construction quality & Simple sound design
Drainage of embankment during overflow
Hydraulic EngineeringDischarge capacity estimate
Downstream dissipation structure
Down-to-earth considerationsHuman interferences
Vandalism (Brushes Clough; Africa)
Prototype experiences: no better proof ofdesign soundness than successful prototype operationNo need to re-invent the ‘wheel’
![Page 31: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/31.jpg)
Summary and Conclusion
Embankments & Earthfill structures�Erodible systems when overtopped
Overtopping protection systemsMinimum Energy Loss weirs & spillwaysConcrete stepped spillwaysPrecast concrete blocksGabion stepped spillwaysMacro-roughness elements
Design and Construction must be soundNo better proof of design soundness than successful prototype operationLearn from successful designs !!!
![Page 32: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/32.jpg)
Look forward seeing you at the5th International Symposium on
Hydraulic Structures25-27June 2014
Full Paper submission deadline: 2 December 2013
![Page 33: Chanson H.“Embankment dam spillways and energy dissipators”](https://reader033.fdocuments.net/reader033/viewer/2022050722/58a03b4f1a28abae4a8c7021/html5/thumbnails/33.jpg)
THANK YOU
http://espace.library.uq.edu.au/list/author_id/193/