Rc sop
1
Rb =
(8)
H s tan α γb γ h γ f γβ
where
Qb = dimensionless overtopping rate for breaking waves
q = average overtopping rate (in cfs per ft width)
Rb = dimensionless crest of beach profile with breaking waves
Rc = crest height of beach profile above still-water line
γb = reduction factor for influence of a berm
γh = reduction factor for influence of shallow foreshore
γf = reduction factor for influence of roughness
γ$ = reduction factor for influence of angle of wave attack
The relationship recommended by VJ for design is
Qb = 0.06e-4.7Rb
(9)
Similar relationships are available for nonbreaking wave conditions, as follows
q
Qn =
(10)
3
gH
s
Rc
1
Rn =
(11)
H s γb γ h γ f γβ
where
Qn = dimensionless overtopping rate for nonbreaking waves
Rn = dimensionless crest of beach profile with nonbreaking waves
and the recommended design relationship for nonbreaking waves is
Qn = 0.2e-2.3Rn
(12)
There are several constraints on the previous relationships given by VJ,
based on the range of conditions tested and the nature of the laboratory testing.
The product of all γ reduction factors is limited to a minimum value of 0.5. The
accepted range of application of the breaking wave relationship is for 0.3<Rb<2.
21
Chapter 3
Modeling Approach
Previous Page
