height in a given depth since the figures
observed dependence of d^/H^ and
in Figure 2-66 are given by
take into
on beach
considération the
slope. The curves
db =
1
t
(2-91)
b -(aHfe/gT2)
where a and b are functions of the beach slope m, and may be approxi
mated by
a = 1.36g (1 -e-19m)
1.56
(l + e"19,5m)
(2-93)
Breaking waves hâve been classified as spilling, plunging or surging
depending on the way in which they break (Patrick and Wiegel, 1955), and
(Wiegel, 1964). Spilling breakers break gradually and are characterized
by white water at the crest. (See Figure '2-67.) Plunging breakers curl
over at the crest with a plunging forward of the mass of water at the
crest. (See Figure 2-68.) Surging breakers build up as if to form a
plunging breaker but the base of the wave surges up the beach before the
crest can plunge forward. (See Figure 2-69.) Further subdivision of
breaker types has also been proposed. The term collapsing breaker is
sometimes used (Galvin, 1968) to describe breakers in the transition from
plunging to surging. (See Figure 2-70.) In actuality, the transition
from one breaker type to another is graduai without distinct dividing
Unes; however, Patrick and Wiegel (1955) presented ranges of H^/L^ for
several beach slopes for which each type of breaker can be expected to
occur. This information is also presented in Figure 2-65 in the form of
three régions on the
vs. H^/Lo plane. An example illustrating the
estimation of breaker parameters follows.
************** EXAMPLE PROBLEM **************
GIVEN: A beach having a 1:20 slope; a wave with deepwater height of
= 5 feet and a period of T = 10 seconds. Assume that a refraction
analysis gives a refraction coefficient, Kr = (b^/b)1/2 = 1.05 at the
point where breaking is expected to occur.
F
• The breaker height H£> and the depth d£> at which breaking occurs
SOLUTION: The unrefracted deepwater height Ho can be found from
h;
Vf
b /
(See Section 2.32),
2-124
observed dependence of d^/H^ and
in Figure 2-66 are given by
take into
on beach
considération the
slope. The curves
db =
1
t
(2-91)
b -(aHfe/gT2)
where a and b are functions of the beach slope m, and may be approxi
mated by
a = 1.36g (1 -e-19m)
1.56
(l + e"19,5m)
(2-93)
Breaking waves hâve been classified as spilling, plunging or surging
depending on the way in which they break (Patrick and Wiegel, 1955), and
(Wiegel, 1964). Spilling breakers break gradually and are characterized
by white water at the crest. (See Figure '2-67.) Plunging breakers curl
over at the crest with a plunging forward of the mass of water at the
crest. (See Figure 2-68.) Surging breakers build up as if to form a
plunging breaker but the base of the wave surges up the beach before the
crest can plunge forward. (See Figure 2-69.) Further subdivision of
breaker types has also been proposed. The term collapsing breaker is
sometimes used (Galvin, 1968) to describe breakers in the transition from
plunging to surging. (See Figure 2-70.) In actuality, the transition
from one breaker type to another is graduai without distinct dividing
Unes; however, Patrick and Wiegel (1955) presented ranges of H^/L^ for
several beach slopes for which each type of breaker can be expected to
occur. This information is also presented in Figure 2-65 in the form of
three régions on the
vs. H^/Lo plane. An example illustrating the
estimation of breaker parameters follows.
************** EXAMPLE PROBLEM **************
GIVEN: A beach having a 1:20 slope; a wave with deepwater height of
= 5 feet and a period of T = 10 seconds. Assume that a refraction
analysis gives a refraction coefficient, Kr = (b^/b)1/2 = 1.05 at the
point where breaking is expected to occur.
F
• The breaker height H£> and the depth d£> at which breaking occurs
SOLUTION: The unrefracted deepwater height Ho can be found from
h;
Vf
b /
(See Section 2.32),
2-124