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Bed topography in the bend
b) Lateral bed geometry
R [m]
6.5
0.0
6.3
6.1
5.9
5.7
5.5
0.2
Scour depth [m]
0.4
0.6
6.5
0.0
6.3
6.1
R [m]
5.9
5.7
5.5
0.8
Scour depth [m]
0.2
0.4
6.5
0.0
6.3
6.1
R [m]
5.9
5.7
5.5
0.6
0.8
Scour depth [m]
0.2
0.4
0.6
0.8
Upstream scour
Downstream scour
Bendegom
Engelund
Bridge
Kikkawa
Reindl
Zimmermann
Falcon
Odgaard
Peter
Figure 3.14: Comparison of different formulae with the measured bed topography (upstream, downstream)
with Q = 210 l/s and S 0 = 0.35%, 0.5%, 0.7%, (from left to right) R c = 6.0 m, B = 1.0 m
The shape of the predicted bed topography in radial direction (Fig. 3.14) fits in general quite well
with the measured one in the center region. Especially towards the outer bank, an important difference
between predicted and measured bed geometry can be observed. This is due to the fact
that most equations use an exponential cross-section profile, except ZIMMERMANN whose profile
is linear. The tests show that the lateral bed geometry is rather s-shaped.
EPFL Ph.D thesis 2632 - Daniel S. Hersberger November 9, 2002 / page 65