Table 7 (Continued) 



Date(s) Construction and Rehabilitation History 



1958- of the trunk; 351 of the 598 tribars placed were reinforced; and 

 1959 concrete cap with reinforced concrete posts was added to the crown 

 (cont.) in the repaired area. Hurricane Dot (1 August 1959) produced 



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 9 in.) was noted. 



1959- Detailed surveys of 148 tribars during this 4-year period showed 

 1963 settlements of up to 3 in., except for two tribars that had 



settled approximately 2 ft each. 



1967 After the storm of 8-13 April 1967 (maximum wave height of 15 ft 



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. 



1968- After the storm of 16 June 1976, a field inspection and subsequent 



1976 underwater inspection revealed 98 tribars broken in the one-layer 

 tribar area, 43 above water and 55 below water. Damage was 

 thought to be due possibly to slippage of the tribar toe. Model 

 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. 



1977 The existing one-layer tribars and a 300-ft section of the sea- 

 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 +5.0 ft mllw over 

 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 

 was a 12-sec, 19.4-ft breaking wave in an 18.5-ft water depth. On 

 the other hand, the design condition for the dolosse overlaying 

 the old existing armor stone was a 16-sec, 8.9-ft breaking wave in 

 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 $2,000,000. Typical 

 cross sections of the repair areas are shown in Figure 17. 



(Continued) 



(Sheet 2 of 3) 



32 



