ERDC/CHL CHETN-III-66
June 2003
relative to the x, y, and z axes were obtained as well. No broken/cracked armor units were
documented during the walking inspection.
The September 2001 photogrammetric survey indicated minimal horizontal and vertical movement
of the targeted units relative to the previous survey. Maximum movements of the targets in the
horizontal and vertical directions, respectively, were 0.10 m and 0.13 m (0.34 ft and 0.43 ft). The
average movements of all horizontal and vertical targets, respectively were 0.03 and 0.05 m (0.1 and
0.16 ft). Maximum movements of the targeted armor unit centroids were 0.0914 and 0.085 m (0.3
and 0.28 ft) in the horizontal and vertical directions, respectively, while average movements were
0.0304 and 0.0335 m (0.1 ft and 0.11 ft) in the horizontal and vertical directions. Changes in the
rotation angle of the armor units varied from 0.01 to 0.36 deg with an average of 0.1 deg. No broken
or cracked armor units were observed during the walking inspection. The structure is considered to
be in excellent condition.
MANASQUAN INLET JETTIES, NJ: Manasquan Inlet is located on the Atlantic Coast of New
Jersey. It provides the northernmost connection between the ocean and the New Jersey Intracoastal
Waterway. The inlet is stabilized by two jetties, spaced 121.92 m (400 ft) apart. A major
rehabilitation of the jetties was completed in 1982. The north jetty is 374.90 m (1,230 ft) long, and
the south jetty is 313.94 m (1,030 ft) in length. The project was monitored under the MCNP
Program during the period June 1982 through October 1984 (Gebert and Hemsley 1991).
Photogrammetric analysis of armor unit movements and broken armor unit surveys of the outer
portions of the jetties were included in the initial monitoring effort. Base conditions were estab-
lished in 1982 with additional surveys through 1984. The structure was revisited under the "Periodic
Inspections" work unit in 1994 (Bottin and Gebert 1995) and 1998 (Bottin and Rothert 1999).
During the major rehabilitation of
1982, the outer 121.92 m (400 ft) of
the north jetty (Figure 5) and 76.2 m
(250 ft) of the south jetty were
armored with 14,514.96-kg (16-ton)
dolosse. The jetty crests were con-
crete caps with elevations of
+4.26 m (+14 ft). Side slopes for the
dolosse were 1V:2H. Additional
repairs were conducted in 1997 that
included the placement of 29 CORE-
LOCsTM on the north jetty and 16
CORE-LOCs on the south structure.
Also, some of the dolosse were
repositioned to improve interlocking
and allow space for the new CORE-
LOCs. Several broken dolosse were
removed. The CORE-LOCs used Figure 5. Manasquan north jetty
for the repairs were 17,236.51-kg
(19-ton) units.
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