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WINDAMb -e (Windows Dam Analysis Modules). WINDAM Technology Workshop Sept 1-3, 2009. WINDAM PROGRESSION. WINDAMb : Breach evaluation of homogeneous embankment Failure of the slope protection is beginning point for breach erosion computations Breach resulting from overtopping
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WINDAMb-e(Windows Dam Analysis Modules) WINDAM Technology Workshop Sept 1-3, 2009
WINDAM PROGRESSION • WINDAMb: Breach evaluation of homogeneous embankment • Failure of the slope protection is beginning point for breach erosion computations • Breach resulting from overtopping • Single breach evaluated • Four stage process • Option of two headcut migration models • Erosion and discharge stage dependent • Breach timing and outflow predicted
WINDAM PROGRESSION • WINDAMb: Breach evaluation of homogeneous embankment • Supporting Research and Development • Laboratory – physical modeling • Data Sets – Failure case histories • Algorithms – computational model development • Model Comparisons • Computational Model – Code & Interface Development & Testing
Steep Channel Studies Laboratory Laboratory Algorithms • Steep Channel • Phase 1 Failure • Steep Channel Flume Tests • Headcut Development • Embankment Flume Tests • Headcut Migration • Breach Widening • Embankment • Widening • Discharge Model • Discharge • Breach Widening • Erodibility • Discharge Model • Erodibility Data Sets Computer Models • ARS Lab Data Additional Data SIMBA • Case Studies WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
Laboratory Laboratory Algorithms Flume Tests • Steep Channel • Phase 1 Failure • Steep Channel Flume Tests • Headcut Development Flume Tests • Embankment • Headcut Migration • Breach Widening • Embankment • Widening • Discharge Model • Discharge • Breach Widening • Erodibility • Discharge Model • Erodibility Data Sets Computer Models • ARS Lab Data Additional Data SIMBA • Case Studies WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
Laboratory Laboratory Algorithms Overtopping Failure Studies • Steep Channel • Phase 1 Failure • Steep Channel Flume Tests • Headcut Development • Embankment Flume Tests • Headcut Migration • Breach Widening • Embankment • Widening • Discharge Model • Discharge • Breach Widening • Erodibility • Discharge Model • Erodibility Data Sets Computer Models • ARS Lab Data Additional Data SIMBA • Case Studies WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
Erodibility Measurement Laboratory Laboratory Algorithms • Steep Channel • Phase 1 Failure • Steep Channel Flume Tests • Headcut Development Flume Tests • Embankment • Headcut Migration • Breach Widening • Embankment • Widening • Discharge Model • Discharge • Breach Widening • Erodibility • Discharge Model • Erodibility Data Sets Computer Models • ARS Lab Data Additional Data SIMBA • Case Studies WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
Laboratory Algorithms • Steep Channel • Phase 1 Failure Flume Tests • Headcut Development • Embankment • Headcut Migration • Breach Widening • Widening • Discharge Model • Discharge • Erodibility Data Sets Data Sets Data Sets • ARS Lab Data Computer Models • ARS Lab Data • ARS Lab Data Additional Data Additional Data Additional Data SIMBA • Case Studies • Case Studies • Case Studies WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
Laboratory Algorithms Historical Case Study Data • Steep Channel • Phase 1 Failure Flume Tests • Headcut Development • Embankment • Headcut Migration • Breach Widening • Widening • Discharge Model • Discharge • Erodibility Data Sets Data Sets Data Sets • ARS Lab Data Computer Models • ARS Lab Data • ARS Lab Data Additional Data Additional Data Additional Data SIMBA • Case Studies • Case Studies • Case Studies WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
Algorithms Laboratory Headcut Migration Algorithms • Phase 1 Failure • Steep Channel • Phase 1 Failure • Headcut Development Flume Tests • Headcut Development • Headcut Migration • Embankment • Headcut Migration • Breach Widening • Widening • Widening • Discharge Model dX/dt • Discharge • Discharge • Erodibility Data Sets Computer Models • ARS Lab Data • Two Headcut Migration Models • Stress Based • dX/dt = Hkd(te – tc)/[2Ev] • Energy Based • dX/dt = C(qH)1/3 Additional Data SIMBA • Case Studies WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
Laboratory Algorithms • Steep Channel • Phase 1 Failure Flume Tests • Headcut Development • Embankment • Headcut Migration • Breach Widening • Widening • Discharge Model • Discharge • Erodibility SIMBA Data Sets Computer Models • ARS Lab Data Computer Models Additional Data SIMBA SIMBA • Case Studies WINDAM a) allowable overtopping b) breach WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
WHAT IS SIMBA? • Philosophy • Use fundamental relations to represent the dominant physical processes • Evaluate/validate and refine relations and algorithms as appropriate from laboratory tests and available data (Avoid calibration: focus on fundamental processes) • Formulate in terms of parameters available for field use (material parameters are key)
Laboratory Algorithms • Steep Channel • Phase 1 Failure Flume Tests • Headcut Development • Embankment • Headcut Migration • Breach Widening • Widening • Discharge Model • Discharge • Erodibility Data Sets Computer Models • ARS Lab Data Computer Models Additional Data SIMBA SIMBA • Case Studies WINDAM a) allowable overtopping b) breach WINDAM a) allowable overtopping b) breach Model Comparisons • NWS Breach, • HR Breach, • FireFox, & others
EROSION COMPUTATIONS • Four stage process • Development of a headcut on downstream slope • Advance of the headcut through the crest • Advance of the headcut into the reservoir • Widening during drawdown
1) HEADCUT FORMATION 2) HEADCUT ADVANCE (through crest) 4 STAGE Breach Erosion Model 3) HEADCUT ADVANCE (into reservoir) 4) BREACH WIDENING
Key Embankment Erosion Processes Impinging Jet Scour Surface Detachment dY/dt dY/dt Headcut Migration Widening dW/dt dX/dt
WINDAM DEVELOPMENT PLANS • WINDAMc: Breach evaluation of homogeneous embankment expanded. • Breach resulting from internal erosion. • Single breach evaluated • Erosion and discharge stage dependent • Breach timing and outflow predicted
Causes of Dam Failures Percentage Overtopping & Spillway 23 - 52% Piping/Seepage/Internal Erosion 25 - 44% Slides 2 - 15% Miscellaneous 9 - 40% (Vijay Singh - “Dam Breach Modeling Technology” 1993)
Internal Erosion Failure Studies
WINDAM DEVELOPMENT PLANS • WINDAMd: Breach evaluation expanded • Potential failure initiation at toe, berms, and groins. • Alternative embankment slope protection materials (i.e. blocks, reinforced vegetation)
WINDAM DEVELOPMENT PLANS • WINDAMe: Breach evaluation expanded • Breach evaluation of Multiple materials in zoned embankment due to overtopping/ internal erosion.
WINDAM TIMELINE • WINdowsDam Analysis Modules (WINDAM) is a modular software application, being developed for analysis of earth embankments. • The development is being carried out in stages: • WINDAMa (alpha spr. 2006, beta fall 2006) • WINDAMa+ (alpha fall 2007, beta spr. 2008) • WINDAMb (alpha smr. 2009, beta wntr. 2009) • WINDAMc (alpha smr. 2011, beta spr. 2012) • WINDAMd (alpha fall 2013, beta spr. 2014) • WINDAMe (alpha fall 2015, beta spr. 2016