Date(s) 
1977T- 
1979 
(cont. ) 
1980 
Table 12 (Concluded) 
Construction and Rehabilitation History 
the base of the existing jetty and extended 10 ft beyond the end of 
the new cover layer. The seaward end repair was identical to the 
1971-1972 work, except that 1V:3H side slopes were used throughout. 
Displaced cover stone was reset on the adjacent 100 ft of jetty. The 
north jetty shore protection was extended 1,470 ft along the channel 
shoreline; this included 150 ft of the existing shore protection 
which was salvaged and rebuilt, and repairs were made to the existing 
section. The design was nearly identical to that used in 1968 on the 
existing shore protection. (Toe protection was 200 to 1,000 lb and 
placed with a top width of 5 ft.) The jetty design was based on 
Hudson's equation with a maximum wave height of 26.5 ft (trunk) and a 
maximum surge level of +10 ft mlt. Similar to previous improvements, 
the selected jetty design was chosen for economic and practical 
considerations in lieu of a "no damage" design. Total cost of the 
jetty repairs and shore protection was $5,905,000 using approximately 
140,000 tons of stone. 
In August, storm waves from Hurricane Allen caused significant damage 
to the jetty heads and a section of the north jetty trunk had been 
breached. The breached section was about 50 ft long and located 
350 ft from the head. 
There are several places along the jetties where the foundation has 
settled, resulting in the cover stone lying be*ow mlt. 
CHANNEL SIDE GULF SIDE 
30° COVER STONE 
16 TO 18 TON 
TYPICAL SECTION 
SHOWING CAVITY IN JETTY 
TYPICAL SECTION 
AFTER RELEASE OF COVER STONE 
TYPICAL TRUNK SECTION 
STA 2+850 TO STA 3+900 
1965-66 SOUTH JETTY SECTIONS 
GULF SIDE TYPICAL SECTION 
tee SHOWING REPAIRED JETTY 
TYPICAL CONCRETE CAP REPAIRS 
(SOUTH JETTY-1965, NORTH JETTY-1979° 
CHANNEL SIDE 
COVER STONE 
16 TO 18 TON 
COVER STONE 
16 TO 18 TON 
Figure 15. Typical repair sections of the Brazos Island jetties 
52 
