Simulating Overtopping of seawall defences

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Simulating Overtopping of seawall defences B.D.
Rogers, M.V. McCabe, P.K. Stansby, D.A. Apsley
RCUK Research Fellow School of MACE
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Outline

• Introduction to Overtopping
• The need for numerical models
• Numerical Model 1
• Boussinesq-type model
• Modification for Seawall
• Numerical Model 2
• Smoothed Particle Hydrodynamics (SPH)
• Effect of the recurve wall
• Results
• Overtopping events and volumes

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Prediction of Wave Overtopping

• Physical Models

• Empirical Data

• Numerical Modelling?

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Nonlinear Shallow Water Equations
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Shallow Water and Boussinesq Equations with a
Vertical Wall
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Shallow Water And Boussinesq (SWAB) Model
Validation
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Wave Overtopping Volumes, Prototype Scale
H
3.41m,
H
/
L
0.04
m0
0
0
6
/m)
5
3
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Cumulative Volume (m
3
2
1
0
0
200
400
600
800
1000
1200
Time (s)
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ExampleOvertopping and Beach Level at Walcott
Link to Movie
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2007 Storm Overtopping Rates
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Detailed modelling requires SPH
Smoothed Particle Hydrodynamics (SPH)
Overtopping, flooding and inundation
Breaking waves on beaches
Very complex multi-phase multi-scale highly
nonlinear problems
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The Future (Multi) Hybrid Chips

• Dual-SPHysics (cpu gpu) SPEEDUPS of 100 for a
  Desktop machine Supercomputer of 1000s cores
• Crespo et al.

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SPH simulation
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SPH simulation
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SPH simulation
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SPH simulation
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SPH simulation
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SPH simulation
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3m
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Overtopping volumes from SPH Simulations

• Results
• With the same bathmetry from the Boussinesq
  simulations overtopping events of 2400 litres/m
• With the Recurve wall overtopping event of 540
  litres/m
• Comparison with Boussinesq Eurotop

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Thank you

• Acknowledgements
• Maurice McCabe
• Nicolas Chini
• Peter Stansby
• SeaZone bathymetry below the low water line
• Environment Agency (EA) beach profile above the
  low water line