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Coastal Engineering: Theory and Practice
Cw
métré run (m3/s/m) at the base of the return wall and is the same as that
at the crest of the slope for a smooth imperméable crest.
A and B are the same empirical coefficients given in Table 6.4. A dimensionless wall height is defined as,
IV. =
(6.26)
Where Wh is the height of the wave return wall and Rc is the freeboard
to the top of the wall as previously defined. From here on the procedure
for imperméable and imperméable structures differs. For an imperméable
structure, given the dimensions wall height, the seaward slope of the sea wall
and the set-back distance of the wave return wall, Table 6.5 provides values
of an adjustment factor Af which in terms used to define an “adjusted slope
freeboard” given by:
X* = AfRc
(6.27)
Figure 6.6 is then used to détermine a discharge factor (Df) for the
given conditions so that the mean discharge over the wall is:
Qw = QmDf
(6.28)
The overtopping discharge can both increase significantly and decrease
depending on the wave approach angle. The ratio of the discharge under
angled wave attack to perpendicular attack, Or in the case is given as:
Or = -1.18In(Df) - 0.40
(6.29)