impact - wp4 dam-break induced floods and sediment movement progress report
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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. - PowerPoint PPT PresentationTRANSCRIPT
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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IMPACT - WP4IMPACT - WP4
Dam-break inducedDam-break induced floodsfloodsand sediment movementand sediment movement
Progress report
Université catholique de Louvain
Yves Zech, Benoit Spinewine and Sandra Soares Frazão
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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Aims and objectivesAims and objectives
Improve the prediction
of the motion of sediments
in association with catastrophic floods
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Dam-break floods and sediment movement
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MotivationMotivation
• Dike breaching
BitterfeldRiver ElbeGermanyAugust 2002
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MotivationMotivation
• Dike-breaching wave
GlashütteMüglitzGermanyAugust 2002
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MotivationMotivation
• Debris flow
WeisensteinRiver ElbeGermanyAugust 2002
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Issues of IMPACT WP4 researchIssues 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
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Scope of the researchScope of the research
• Near-field – Uniform debris flow– Severe transient debris flow
• Far-field – Intense transport– Bank erosion and geomorphic changes
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Near field : problems to be solvedNear field : problems to be solved
• Initiation of movement– Acting forces– Vertical effects– Inertial effects– Sediments bulking
• Propagation– Intense scouring– Debris-flow front
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Debris flow : research programmeDebris flow : research programme
• Experiments : acting forces (UDT)– Uniform material
• Months 1-18
– Graded material• Months 18-32
BM UDT ?
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Debris flow : research reportDebris 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
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Debris flow : research reportDebris flow : research report
• Mature debris flow: collisional + frictional
• Rigid-bed debris flowcollisional
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Dam-break floods and sediment movement
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Debris flow : research reportDebris flow : research report
• Mature debris flow
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Debris flow : research reportDebris 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 external
and internal tangentialstress
• Effect of added mass
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Debris flow : research reportDebris flow : research report
• Rigid bed debris flow– Concentration
– Velocity profile
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.000 0.100 0.200 0.300 0.400 0.500 0.600 0.700 0.800
c [-]
z [
m]
c-theoreticalprofile
c-exsperimentalprofile
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.000 0.500 1.000 1.500 2.000
u [m /s]
z [
m]
u-theoreticalprofile
u-exsperimentalprofile
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Near-field dam break : programmeNear-field dam break : programme
• Experiments: uniform material (UCL)– Same bed levels
• Months 1-9
– Initial step in bed levels• Months 1-9
BM UCL 2
BM UCL 1
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Near-field dam break : research reportNear-field dam break : research report
• Experiments: uniform material (UCL)– Same bed levels
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Dam-break floods and sediment movement
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Near-field dam break : programmeNear-field dam break : programme
• Mathematical modelling (UCL)– 1D model: months 1-6
– 2D-V model: months 21-32BM UCL 3
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• Mathematical modelling (UCL)– 1D model:
• Velocity distribution• (Concentration distribution)
Near-field dam break : research reportNear-field dam break : research report
pure water
mixture
u
z
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Near-field : research programmeNear-field : research programme
• Validation of codes (UDT, UCL, Cem)– Uniform debris flow (to be clarified)
• Months 11-12
BM UDT ?
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Near-field : research programmeNear-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 2BM UCL 1
BM UCL 3
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Far field : problems to be solvedFar 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
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Far field : research programmeFar field : research programme
• Laboratory experiments– Dam-break in an initially prismatic valley
(UCL)• Uniform material• Graded material
• Months 13-20
BM UCL 4
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Far field : research programmeFar field : research programme
• Laboratory experiments– Large-scale model (Châtelet)
• Prismatic valley• Enlargement
• Months 24-31
BM Chat
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Far field : research programmeFar field : research programme
• Field experiments– Norwegian dam (SG)
• Geomorphic survey (to be checked)
• Months 9-12 and 19-21
BM Norway
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Far field : research programmeFar field : research programme
• Numerical modelling– Extension of 2D-H model (UCL)
• Bank erosion
• Months 12-20 50°
37°
85°
Vbank
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Far field : research programmeFar field : research programme
• Validation (UCL, UDT, Cemagref, IST)– Laboratory tests
• Prismatic valley (UCL)• Enlargement (Châtelet)
BM UCL 4 BM Chat
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Far field : research programmeFar field : research programme
• Validation (UCL, UDT, Cemagref, IST)– Field tests
• WP2 Norwegian dam ?• Lake Ha!Ha!
• Months 33-35
BM Ha!Ha!
BM Norway
Brooks and Lawrence1999
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Benchmark summaryBenchmark summary
• Near field
• Far field
BM Ha!Ha!
BM Norway
BM UCL 4
BM Chat
BM UCL 3BM UCL 2BM UCL 1
BM UDT ?
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Dam-break floods and sediment movement
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IMPACT - WP4IMPACT - WP4
Dam-break inducedDam-break induced floodsfloodsand sediment movementand sediment movement
Progress report
Université catholique de Louvain
Yves Zech, Benoit Spinewine and Sandra Soares Frazão