Se ha denunciado esta presentación.
Se está descargando tu SlideShare. ×

using embankment dams for flash flood risk management

Próximo SlideShare
Hydraulics  structures
Hydraulics structures
Cargando en…3
×

Eche un vistazo a continuación

1 de 34
1 de 34

using embankment dams for flash flood risk management

Descargar para leer sin conexión

the presentation contains an overview on flash floods, common measures of flood protection, embankment dams, and shows the steps of designing the dam. also listing some useful software.

the presentation contains an overview on flash floods, common measures of flood protection, embankment dams, and shows the steps of designing the dam. also listing some useful software.

Más Contenido Relacionado

Audiolibros relacionados

Gratis con una prueba de 30 días de Scribd

Ver todo

using embankment dams for flash flood risk management

  1. 1. Hydraulic Analysis Embankment Dams Water Resources Research Institute Web: www.wrri.org.eg Eng. Ahmed Adel Saleh email: norahmed1@gmail.com
  2. 2. Outlines • Introduction • Conceptual model • Flash Flood in Egypt • Measures to eliminate the flash flood problem • Embankment dams • Applications from WRRI • Modeling and simulation tools
  3. 3. Conceptual model of flash flood protection system
  4. 4. Rainfall-Runoff Model Flood Hydrograph Design of Hydraulic Structures Structural measures Nonstructural measures The Design Flood Hazard Assessment Vulnerability Analysis Vulnerability Assessment Risk Assessment Flash flood risk management plan Hydrology No Need Hydraulics Engineering Cost benefit analysis Codes / Standards
  5. 5. Nonstructural FRM Measures Early Warning Elevation MovingFlood Proofing Preparedness
  6. 6. Structural FRM Measures Reservoirs Floodwalls Levees Ring wall Channels Straightening Clearing and snaggingClosure structures Bridge modifications Conveyance modifications Pumping Channel diversions Dams Beach Nourishment
  7. 7. Embankment dams Overview https://www.youtube.com/watch?v=fqceTkveWTo • Types of dams • Main characteristics of the embankment dams • Failure of Embankment Dams • Main steps of an embankment dams projects
  8. 8. TYPESOFDAMS Gravity Concrete, rubble masonry Arch Concrete Buttress Concrete timber steel Embankment Earth rock Simple Embankment (Homogeneous with low permeable upstream ) Impervious Foundation Impervious Core
  9. 9. Embankment dams • Rely on their weight to resist the flow of water. • Massive dams made of earth or rock. • Constructed where the foundation are weak to support the masonry dam or where the suitable competent rocks are at greater depth. Broader at the base Smaller in height
  10. 10. Main parts of an embankment dams • Dam body: Body forms the main part of a dam as an impervious barrier • Reservoir: It is the artificial lake behind a dam body • Spillway: is that part of a dam to evacuate the flood water from reservoir. • Water intake structures: is a facilityy to withdraw water from a reservoir. • Diversion facilities: To redirect the streamflow from construction area Mehmet Özger: Dams (Barajlar)
  11. 11. Choosing the location/type of a dam Choosing a suitable location of dam Topographic Requirement Geotechnical suitability Sedimentation possibilities Submergence costs Hydrologic adequacy Spillway site availability Selection of the type of dam Availability of construction material Environmental reasons (Quarrying) Availability of skilled workers Seismicity Hydrology (Overtopping) Budget Time available Earth-fill Buttress arch 15 • Small Dam 15-50 • Large Dam 50 • High Dam
  12. 12. Failure Causes of Embankment Dams
  13. 13. Dam axis • More loads are allowed • Easier in constructing • Better for small dams
  14. 14. Project design • Max. lake elevation • Spillway capacity • Crest elevation Hydrologic design • Static & dynamic loads • Spillway profile • Outlet dimensions Hydraulic design • Stress distribution • Required reinforcementStructural design • Sedimentation • Environmental • Social • … Other studies
  15. 15. Investigation&Data collecting Topographical investigations Rock classification Boring exploration • core drilling • sounding In-situ testing • Permeability • bearing capacity • compressibility Meteorological and hydrological surveys Design Stability of Dam Body •Stability against sliding failure of embankment (Pore-water pressure, shear strength) •Seismic stability •Stability at the contact face of dam body and base foundation Seepage Through Embankment and Foundation •pore-water pressure •leakage through foundation •critical velocity •Piping •critical hydraulic gradient Construction Planning for Construction •Construction equipment (roller, carrier, bulldozer, ...) •Foundation treatment (grouting, drainage) •Placement (execution management, field and laboratory testing) •Observation (pore-water pressure, settlement, earth pressure, deformation) Maintenance and Repair
  16. 16. Small earth-fill dams
  17. 17. Small earth-fill dams Advantages • Construction materials are easily available • Simple design criteria • Simple foundation preparation required • Resist settlement and movement Disadvantages • Not appropriate for rainy climates • Higher possibility to damage or slide • Lack of compaction of material leads to increased seepage • Continuous monitoring and assessment needed • Many of failures are caused by careless construction
  18. 18. Small rock-fill dams Typical Cross-section Best quality Larger bolderLess quality than D Well-graded, smaller rock and gravel Minimum of 4.5 to 6 m
  19. 19. Small rock-fill dams Advantages • Suitable when: • Short construction time is available • Little earth-fill materials Disadvantages • More costly
  20. 20. https://www.youtube.com/channel/UC6sqyiQ04kG9uXcsdJNFrwg
  21. 21. https://www.omsi.edu/exhibits/damsimulation/
  22. 22. HEC-Geo-RAS • Saving the time by reading the Geometric data from Arc-GIS https://www.youtube.com/watch?v=36wdta8JGbU

×