ERDC/CHL CHETN-III-66
June 2003
slope and head were armored with 16,147.89-kg (17.8-ton) tribars. Subsequent repairs involved
9,979.03-kg (11-ton) dolos along the sea-side trunk and 20,865.25-kg (23-ton) dolos around the head
of the structure. The 5,896.70-kg (6.5-ton) tribars were used to repair a portion of the harbor-side
slope.
During the initial photogrammetric survey of September 1995, selected armor units 16,147.89-kg
(17.8-ton) tribars and 9,979.03- and 20,865.25-kg (11- and 23-ton) dolosse) were targeted (three
targets each) and precise positions of these units were obtained as well as centroid data and
orientations of the targeted armor units. The initial broken armor unit survey of the Nawiliwili
Harbor breakwater revealed a total of 70 broken or cracked armor units above the waterline. Of the
70 broken or cracked armor units, 39 were 9,979.03-kg (11-ton) dolos, 19 were 16,147.89-kg
(17.8-ton) tribars, 8 were 20,865.25-kg (23-ton) dolosse, and 4 were 16,147.89-kg (6.5-ton) tribars.
Considering the types of breaks, 54 percent of the 9,979.03-kg (11-ton) dolosse and 63 percent of the
20,865.25-kg (23-ton) dolosse were determined to be mid-shank breaks. Of all the dolos breaks
recorded, 77 percent were straight and 23 percent were angled. Of the 19 broken 16,147.89-kg
(17.8-ton) tribars, 74 percent consisted of one leg broken off through the center of the unit. The four
broken 6.5-ton tribars on the harbor-side of the breakwater appeared to have been placed in that
condition. They seemed to have been fitted on the crest adjacent to the rib cap. It was noted during
the inspection, that due to excessive wave action, broken/cracked armor units along the sea-side
water's edge may have been missed in the previous inspection, since that portion of the structure was
inaccessible by foot.
The September 2001 photogrammetric survey indicated negligible movement of the concrete armor
units on the breakwater relative to the 1995 survey. Maximum movement of the targets established
on the concrete armor units in the horizontal and vertical directions, respectively, was 0.1280 m
(0.42 ft) and 0.1381 m (0.45 ft); and the average movement of all horizontal and vertical targets was
0.0304 m (0.1 ft) and 0.0457 m (0.15 ft). Maximum movements of the targeted armor unit centroids
were 0.1036 m (0.34 ft) and 0.1127 m (0.37 ft) in the horizontal and vertical directions, respectively,
while average movements were 0.0274 m (0.09 ft) and 0.0426 m (0.14 ft) in the horizontal and
vertical directions. Changes in the rotation angles of the armor units varied from 0.0 to 10.2 deg
with an average of 0.8 deg. A broken armor unit survey conducted during August 2001 revealed
77 broken or cracked armor units above the waterline (versus 70 in 1995). Additional broken units
identified since the last survey included five 9,979.03-kg (11-ton) dolosse and two 16,147.89-kg
(17.8-ton) tribars. However, as stated previously, high wave action during the 1995 walking
inspection prevented a close examination of armor units on the sea-side water's edge. Of the seven
additional broken units identified in 2001, six were located along the water's edge and may have
been overlooked in 1995 due to the excessive wave action. Therefore, it appears that minimal armor
unit breakage occurred between 1995 and 2001. Overall, the structure appeared to be in good
condition.
KAHULUI HARBOR BREAKWATER, MAUI, HI: Kahului Harbor is located on the north shore
of the island of Maui. It is protected by two breakwaters. The breakwaters are rich in construction,
repair, and rehabilitation history. In 1931 the east and west breakwaters were extended to their
current lengths of 843.07 and 705.61 m (2,766 and 2,315 ft), respectively. The most recent
rehabilitation occurred in 1984. Base conditions were established in 1993 for the outer portions of
the breakwaters (Markle and Boc 1994) under the "Periodic Inspections" work unit of the MCNP
Program. The structure was revisited in 2001 (Bottin and Meyers 2002b).
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