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IMPACT - WP4 Dam-break induced floods and sediment movement Progress report. Université catholique de Louvain Yves Zech, Benoit Spinewine and Sandra Soares Frazão. Aims and objectives. Improve the prediction of the motion of sediments in association with catastrophic floods. Motivation.
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IMPACT - WP4Dam-break inducedfloodsand sediment movementProgress report Université catholique de Louvain Yves Zech, Benoit Spinewine and Sandra Soares Frazão Dam-break floods and sediment movement
Aims and objectives Improve the prediction of the motion of sediments in association with catastrophic floods Dam-break floods and sediment movement
Motivation • Dike breaching Bitterfeld River Elbe Germany August 2002 Dam-break floods and sediment movement
Motivation • Dike-breaching wave Glashütte Müglitz Germany August 2002 Dam-break floods and sediment movement
Motivation • Debris flow Weisenstein River Elbe Germany August 2002 Dam-break floods and sediment movement
Issues of IMPACT WP4 research • Extreme flows intense erosion and solid transport • Intense sediment transport affects flood-wave prediction • Arrival time • Maximum water level • Morphological changes Dam-break floods and sediment movement
Scope of the research • Near-field • Uniform debris flow • Severe transient debris flow • Far-field • Intense transport • Bank erosion and geomorphic changes Dam-break floods and sediment movement
Near field : problems to be solved • Initiation of movement • Acting forces • Vertical effects • Inertial effects • Sediments bulking • Propagation • Intense scouring • Debris-flow front Dam-break floods and sediment movement
Debris flow : research programme • Experiments : acting forces (UDT) • Uniform material • Months 1-18 • Graded material • Months 18-32 BM UDT ? Dam-break floods and sediment movement
Debris flow : research report • Uniform material experiments • Tilting flume (L = 6 m, S0 = 0° to 23°) • Uniform cylindrical PVC particles • Equivalent spherical D = 3.5 mm • Density = 1540 kg/m³ Dam-break floods and sediment movement
Debris flow : research report • Mature debris flow: collisional + frictional • Rigid-bed debris flowcollisional Dam-break floods and sediment movement
Debris flow : research report • Mature debris flow Dam-break floods and sediment movement
Debris flow : research report • Mathematical description (collisional) • Normal stress local equilibrium • Submerged weight overlying grains • Inter-granular collisional contacts (pressure related to granular temperature) • Tangential stress local equilibrium • Relation between externaland internal tangentialstress • Effect of added mass Dam-break floods and sediment movement
Debris flow : research report • Rigid bed debris flow • Concentration • Velocity profile Dam-break floods and sediment movement
BM UCL 2 Near-field dam break : programme • Experiments: uniform material (UCL) • Same bed levels • Months 1-9 • Initial step in bed levels • Months 1-9 BM UCL 1 Dam-break floods and sediment movement
Near-field dam break : research report • Experiments: uniform material (UCL) • Same bed levels Dam-break floods and sediment movement
BM UCL 3 Near-field dam break : programme • Mathematical modelling (UCL) • 1D model: months 1-6 • 2D-V model: months 21-32 Dam-break floods and sediment movement
z pure water mixture u Near-field dam break : research report • Mathematical modelling (UCL) • 1D model: • Velocity distribution • (Concentration distribution) Dam-break floods and sediment movement
Near-field : research programme • Validation of codes (UDT, UCL, Cem) • Uniform debris flow (to be clarified) • Months 11-12 BM UDT ? Dam-break floods and sediment movement
Near-field : research programme • Validation of codes (UDT, UCL, Cem) • 1D dam-break flow in the near field • Months 11-12 • 2D-V dam-break flow • Months 34-35 BM UCL 1 BM UCL 2 BM UCL 3 Dam-break floods and sediment movement
Far field : problems to be solved • Transition from near-field to far-field • Geomorphic changes • Bank erosion and failure • Tractive forces applied • Failure mechanism • Channel widening • Deposition of material • De-bulking • Distribution of sediments • Formation of secondary dams Dam-break floods and sediment movement
Far field : research programme • Laboratory experiments • Dam-break in an initially prismatic valley (UCL) • Uniform material • Graded material • Months 13-20 BM UCL 4 Dam-break floods and sediment movement
Far field : research programme • Laboratory experiments • Large-scale model (Châtelet) • Prismatic valley • Enlargement • Months 24-31 BM Chat Dam-break floods and sediment movement
Far field : research programme • Field experiments • Norwegian dam (SG) • Geomorphic survey (to be checked) • Months 9-12 and 19-21 BM Norway Dam-break floods and sediment movement
Far field : research programme • Numerical modelling • Extension of 2D-H model (UCL) • Bank erosion • Months 12-20 50° 85° V bank 37° Dam-break floods and sediment movement
Far field : research programme • Validation (UCL, UDT, Cemagref, IST) • Laboratory tests • Prismatic valley (UCL) • Enlargement (Châtelet) BM UCL 4 BM Chat Dam-break floods and sediment movement
Far field : research programme • Validation (UCL, UDT, Cemagref, IST) • Field tests • WP2 Norwegian dam ? • Lake Ha!Ha! • Months 33-35 BM Norway Brooks and Lawrence 1999 BM Ha!Ha! Dam-break floods and sediment movement
Benchmark summary • Near field • Far field BM UDT ? BM UCL 1 BM UCL 2 BM UCL 3 BM Chat BM Norway BM UCL 4 BM Ha!Ha! Dam-break floods and sediment movement
IMPACT - WP4Dam-break inducedfloodsand sediment movementProgress report Université catholique de Louvain Yves Zech, Benoit Spinewine and Sandra Soares Frazão Dam-break floods and sediment movement