Construction and Rehabilitation History
of the 598 tribars placed were reinforced; and
of the trunk;
concrete cap with reinforced concrete posts was
crown
1959
in the repaired area. Hurricane Dot (1 August 1959) produced
(cont.
estimated wave heights approaching the 24-ft design wave height at
the structure which caused some minor damage. One reinforced con-
crete post was broken off, one tribar was displaced over the
crown, two tribars were broken, and some downslope slippage of
tribars (maximum of in.) was noted.
Detailed surveys of 1 8 tribars during this
4
period showed
settlements of up to 3 in., except for two tribars that had
1963
settled approximately 2
each.
After the storm of 8-13 April 1967 (maximum wave height of 15 ft
1967
at the structure), an inspection on 9 May 1967 revealed a total of
seven broken tribars--one displaced and one missing--and four
severed concrete posts. (cumulative damage since original con-
struction). The structure was still functioning very well.
After the storm of 1 June 1976, a field inspection and subsequent
6
underwater inspection revealed 98 tribars
in the
1976
area, 43 above water and 55 below water. Damage was
.
thought to be due possibly to slippage of
Model
tribar
tests of the tribar rehabilitation had recommended the use of
large buttressing stone, and there is no evidence of their
existence on the tribar toe.
The existing one-layer tribars and a 300-ft section of the sea-
1977
side slope shoreward of this area were repaired (model tested by
Davidson 1978). Two layers of 11-ton unreinforced dolosse (485
units) were placed from the toe to approximately
ft mllw
the one-layer tribar area. Two layers of the same size unit
(449 units) were placed from the toe to the crown on the sea-side
slope of the trunk for a distance 300 ft shoreward of the tribar
area. The design condition for the dolosse overlaying the tribar
19.4-ft breaking wave in an 18.5-ft water depth. On
was a
the other hand, the design condition for the dolosse overlaying
8.9-ft breaking wave in
the old existing armor stone was a
a 10-ft water depth. Portions of the sea-side slope shoreward of
this area (approximately 300 ft) were repaired with one layer of
7- to 12-ton stone. This armor stone repair was not model tested.
The total cost of repairs was approximately ,000,000. Typical
cross sections of the repair areas are shown in Figure 17.
(Continued)
(Sheet 2 of 3)
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