mo-i-rana - september 2002 dam-break floods and sediment movement 1 impact - wp4 dam-break induced...
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Mo-i-Rana - September 2002
Dam-break floods and sediment movement
1
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
2
Aims and objectivesAims and objectives
Improve the prediction
of the motion of sediments
in association with catastrophic floods
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
3
MotivationMotivation
• Dike breaching
BitterfeldRiver ElbeGermanyAugust 2002
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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MotivationMotivation
• Dike-breaching wave
GlashütteMüglitzGermanyAugust 2002
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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MotivationMotivation
• Debris flow
WeisensteinRiver ElbeGermanyAugust 2002
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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 ?
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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Debris flow : research reportDebris flow : research report
• Mature debris flow: collisional + frictional
• Rigid-bed debris flowcollisional
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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Debris flow : research reportDebris flow : research report
• Mature debris flow
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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Near-field dam break : research reportNear-field dam break : research report
• Experiments: uniform material (UCL)– Same bed levels
Mo-i-Rana - September 2002
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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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 ?
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
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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 ?
Mo-i-Rana - September 2002
Dam-break floods and sediment movement
29
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
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