Table 12 (Continued)
Construction and Rehabilitation History
Date
1957-
The jetties were repaired at their seaward ends. New riprap, core,
and 14- to 18-ton cover stone were used. Existing cover stone was
1959
reset, and concrete was placed (similar to previous capping). A
total of 20,500 tons of stone and 600 cu yd of concrete were placed
at a total cost of 8,000.
Approximately 1,270
of stone
was placed along the
section of channel shoreline adjacent to the landward end of the
north jetty. The purpose of the embankment was to reduce shoreline
erosion which threatened to flank the jetty. A 3-ft-thick layer of
0.5-in. to 200-lb stone was placed at about the mlt contour. The
width of the layer was roughly 25 ft. Total cost of this shore pro-
tection was ,500. In September several sections of the jetties
were damaged during Hurricane Carla. The south jetty received the
of its seaward end was severely damaged,
most damage. About
and large holes developed under several sections of the concrete
cap. The holes were caused by displacement and settlement of cover
and core stone. Near its seaward end, about 200 ft of cap had
collapsed and an additional 70
was severely damaged. On the north
jetty major areas of damage occurred at its seaward end, with 1 0
9
destroyed and a 380-ft channel side section damaged by undermining
near the landward end. The magnitude of stone displacement and
undermining of the cap was much smaller on the north jetty. Damage
to the seaward ends of the jetties was believed to be due partly to
scour along the jetty toes and partly to the existing
side
slopes which were too steep for the existing cover stone and storm
waves
A 1,825-ft section of the south jetty was rehabilitated, and repairs
1965-
of the north jetty. Starting from its seaward end
were made to 580
1966
the south jetty repairs extended a distance of 625 ft along both side
slopes and continued for an additional 1,200 ft on its gulf side, The
ft
crown elevation,
a 20- to 30-ft crown width (seaward end widest),
side slopes on
on
the 200-ft-long head section, and side slopes of
and
remaining gulf and channel sections, respectively. A 3- to 5-ft-thick
bedding layer of 0.5-in. to 200-lb stone was placed, extending from 1
0
(The
layer
to 50 past the toe of the new cover stone.
was used on the
sections.) The core stone varied from a minimum
of 200 lb to maximums of 1,000 and 4,000 lb between landward and sea-
ward ends, respectively. To reduce sand transport through the jetty,
part of the gulf side core stone adjacent to the old cover stone was
combined with 0.5- to
filler stone. The cover stone varied from
2 to 4 tons on the landward gulf side, increasing in size in the sea-
ward direction to a maximum of 1 to 1 tons. The entire channel side
6
8
was 16 to 1 tons). A double layer of cover stone was used on the
8
side slopes of the head section. Additional repairs were made by
(Continued)
49
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