HYDRAULICS BEHAVIOR AND DESIGN CONCEPTUAL OF SPUR DIKE

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HYDRAULICS BEHAVIOR AND DESIGN CONCEPTUAL OF SPUR
DIKE
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Outlines
? Introduction ? Governing Equations ? CIP
Method ? Results ? Design Conceptual
Ushitsu River, Shikoku, Japan
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Introduction
Snow Festival, 2004
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Spur Dike
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Spur Dike
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Governing Equation
Snow Festival, 2004
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Cartesian coordinate system
Continuity eq.
Momentum eq.
where h water depth, u, v average velocity,
tbshear stress, rwater density, H water
surface elevation (zbh), zbbed elevation, n
eddy viscosity, ttime, and x, y spatial
coordinate in Cartesian coordinate system.
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Cartesian coordinate system
Bed shear stress
Eddy viscosity
Shear velocity
where Cfbed friction coefficient, kKarmans
constant, ushear velocity
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Cartesian coordinate system
Bedload eq.
KavacsParker eq.
Hasegawa eq.
where ?non-dimensional shear stress,
?ccritical shear stress,?ccritical
non-dimension shear stress, ?bbed slope,
?ssediment density, s(?s/?-1), NEngelunds
constant, and rradius of curvature.
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Cartesian coordinate system
Sediment transport eq.
where zbbed elevation, lporosity of bed
material.
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Moving boundary-fitted system
Transformed rule
where u?, v?average velocity components in the
of ?, ? direction, ?time, and JJacobian of
coordinate transformed.
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Moving boundary-fitted system
Continuity eq.
Momentum eq.
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Moving boundary-fitted system
Sediment transport eq.
where q?, q?sediment transport rate components
in the ?, ? direction, respectively.
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Bank erosion mechanisms
Fig. (a) bank erosion and migration, (b) bed
aggradation and bank deposition.
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Bank deformation
Fig. (c) bank deformation and renewal of the
computational grid.
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CIP Method
Snow Festival, 2004
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CIP method (Yabe et al., 1990)
CCubic, IInterpolated, PPsuedoparticle
Advection phase
Diffusion phase
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Results
Snow Festival, 2004
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JangShimizu, 2003
Conditions L 12.0 m, b 0.80 m, q 4.50 l/s,
i 1.0, q 40o d 1.25 mm
Experiment
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JangShimizu, 2003
Experiment Results
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JangShimizu, 2003
Conditions L 12.0 m, b 0.80 m, q 4.50 l/s,
i 1.0 nx 83, ny 26, Dx 0.1463 m, Dy
0.0038 m, Dt 0.005 s, d 1.25 mm
L 7.0 m
Initial grid
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Bed contour and bank deformation
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Flow vector and bank deformation
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Run3- Nagata et al., 2000
Conditions L 10.0 m, B 0.30 m, q 1.98 l/s,
i 1.0 d 1.42 mm
Experiment
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Run3- Nagata et al., 2000
Conditions L 10.0 m, B 0.30 m, q 1.98 l/s,
i 1.0 nx 83, ny 26, Dx 0.128 m, Dy
0.0054 m, Dt 0.005 s, d 1.42 mm
L 10.0 m
Initial grid
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Run2- Morita et al., 2005
Conditions L 6.30 m, B 0.80 m, q 8.25 l/s,
i 1/2000 d 0.88 mm
erosion
erosion
deposition
FLOW
Experiment
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Run2- Morita et al., 2005
Conditions L 6.30 m, B 0.80 m, q 8.25 l/s,
i 1/2000 nx 50, ny 20, Dx 0.126 m, Dy
0.04 m, Dt 0.002 s,
Bed elevation
Streamline
Velocity vector
Initial condition
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Run2- Morita et al., 2005
Bed elevation
Streamline
Velocity vector
t 120 min.
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Application 1
Conditions L 80.0 m, B 10.0 m, q 50 m3/s, i
1/2000, d 1.45 mm
Bed elevation
Streamline
Velocity vector
t 0 min.
Equilibrium
????????????????????????????? 2.0 ???? x ??? 0.3
???? ?????????????????? ??? 20.0 ????
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Application 2
Conditions L 80.0 m, B 10.0 m, q 50 m3/s, i
1/2000, d 1.45 mm
t 0 min.
Equilibrium
????????????????????????????? 2.0 ???? x ??? 0.3
???? ??????????????????????? ??? 20.0 ????
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New Conceptual Design of Spur Dike
Snow Festival, 2004
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Spur Dike
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Natural Diversities River Methods
After 2 years
Before
Before
After
Hokkaido, Japan
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Natural Diversities River Methods
Before
Before
After
After
Hokkaido, Japan
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Spur Dike Design
Straight Channel Section Length 0.10B Height 0.
2-0.3HWmax Distance 2-4Lsd, 10-30Hsd Side
Slope 1/20-1/100 Bend Channel Section Length 0.1
0B Height 0.5-1.0HWaver Distance gt2Lsd Side
Slope 1/20-1/100
B
Lsd
B Channel width Lsd Length of spur
dike HWaver Average water depth HWmax Maximum
water depth Hsd Height of spur dike
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THE END