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

Benchmark BM UCL 1

Université catholique de Louvain

Benoit Spinewine and Yves Zech

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

2

Benchmark BM UCL 1Benchmark BM UCL 1

• 1D dam-break flow in the near field– Uniform material– Same bed levels

National Taiwan University

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

3

Physical descriptionPhysical description

• t = 0.0 s

• t = 0.2 s

• t = 0.4 s

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

4

Physical descriptionPhysical description

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

5

Physical descriptionPhysical description

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

6

Analytical descriptionAnalytical description

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

7

ExperimentsExperiments

• Material– Uniform cylindrical PVC pellets– D = 3.2 mm - H = 2.8 mm– Equivalent spherical D = 3.5 mm– Density = 1540 kg/m³– Static granular packing

0.60

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

8L = 0.10 m

ExperimentsExperiments

• Initial conditions– h0 = 0.10 m; hs 0.05 m

– Downstream sediments saturated

h0

hs

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

9

MeasurementsMeasurements

• Layer boundaries

Visual observation

Velocity gradient

Automated detection

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

10

MeasurementsMeasurements

• Velocity: particle tracking (200 fps)• Tracking of tracers particles• Bed material tracking

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

11

xb (t) xf (t)

Expected resultsExpected results

• Wave propagation– Front wave xf (t)– Back wave xb (t)– t = 0.05 s

0.10 s ... 2.00 s

t = 0.05 s

x

t

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

12

Expected resultsExpected results

• Interface levels– zb (t)

zs (t)zw (t)

– x = - 0.50 m - 0.25 m 0.00 m 0.25 m 0.50 m 0.75 m

zw

zs zb

z

x

Mo-i-Rana - September 2002

Dam-break floods and sediment movement

13

IMPACT - WP4IMPACT - WP4

Dam-break inducedDam-break induced floodsfloodsand sediment movementand sediment movement

Benchmark BM UCL 1

Université catholique de Louvain

Benoit Spinewine and Yves Zech