Figure 10.9. Proposed fifth alternative.
Table 10.1. Summary of Computer Hydraulic Conditions.
∆z
A
V
F
H
Ys
T
Q
Yn
rc
Vo
yo
A4
ft
ft
fps
ft
yrs
cfs
ft
ft
ft
fps
ft
1
950
4.24
12.40
17.37
50
51,600
8.17
5,904
8.74
0.72
1.05
8.82
2
1,900
2.12
10.28
15.30
3
2,650
1.52
9.69
14.70
1
950
4.82
13.65
18.50
100
62,000
8.84
6,660
9.31
0.74
1.18
9.63
2
1,900
2.41
11.20
16.20
3
2,650
1.73
10.57
15.60
1
950
5.36
14.82
19.50
200
72,500
9.46
7,379
9.82
0.75
1.32
10.33
2
1,900
2.68
12.14
17.11
3
2,650
1.92
11.38
16.40
Note:
T is the return period, Q is the design discharge, yn is the normal depth from the thalweg level, A is the cross-sectional
area of flow, V is the mean flow velocity, F is the Froude number, H is the antidune height, ys is the scour depth at the
leading portion of riprap bank protection, A4 is the alternative of designs, rc is the radius at the center of a bend, ∆z is the
superelevation, and yo and Vo are the depth and velocity, respectively, for designing riprap sizes.
For design floods with return periods of 50, 100 and 200 years, the normal depths from thalweg
level are determined. Then the cross sectional area and the wetted perimeter can be
computed. Finally, the mean flow velocity, the hydraulic radius, and the Froude number are
calculated.
10.8
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