Table 26 

 Arecibo Harbor Breakwater 

 Arecibo, Puerto Rico, SAJ 



Date(s) Construction and Rehabilitation History 



1944 A 1,200-ft armor stone breakwater was completed, providing protec- 

 tion for the harbor and its 25-ft-deep access channel (Figure 41) . 

 The breakwater cross section (Figure 41, inset) was comprised of 

 25-lb to 10-ton core stone protected with one layer of armor stone, 

 10-ton minimum weight. A recent (1983) visual examination indicated 

 that most of the armor units were 10 to 18 tons) . The side slopes 

 were 1V:1.5H on the ocean side and IV: IH on the harbor side. The 

 crest width and elevation were 20 ft and +15 ft mlw, respectively. 

 The breakwater was constructed along a reef with a depth varying 

 from -20 ft mlw at its seaward end to mlw at its landward end. 



1951- Repair work consisted of resetting armor stone and placing about 

 1952 8,300 tons of new granite stone at an estimated cost of $66,400. 



The structure was rebuilt to its original design geometry and stone 

 sizes, except for the outer 50 ft which was not repaired. Damage 

 resulted from wave action which caused dislodgement of stone and 

 settlement of portions of the breakwater. A subsequent Chief of 

 Engineers report indicated that the armor stone along the slope of 

 the structure showed signs of "sliding." 



1983 A field inspection and a condition survey were made to identify dam- 

 aged areas for rehabilitation purposes. The general damage (Fig- 

 ure 42) was above mlw, and the ocean-side slope of the submerged 

 part of the structure had increased to IV: 2H or greater. In partic- 

 ular, about 160 ft of the seaward end had subsided to approximately 

 mlw. Several areas on the trunk section had unprotected core stone 

 on either side of the structure. 



1984 Rehabilitation of the breakwater consisted of rebuilding the outer 

 end of the breakwater and restoring damaged sections by placing 

 about 42,000 tons of armor stone, ranging in size from 11 to 29 tons 

 (Figure 42) . A double layer of armor stones was provided on the 

 seaward side of the structure along a reach beginning about 350 ft 

 from the shore end of the breakwater and extended toward the outer 

 end, a distance of 450 ft. A double layer of armor stone was placed 

 on both sides of the structure for the next 265 ft. The remaining 

 155 ft, at the seaward end of the structure, was rebuilt to +15 ft 

 mlw, as were the other sections. The crest of the damaged sections 

 was restored to a width of about 26 ft for the first 800-ft reach. 

 The crest of the outer 420-ft section was widened to about 36 ft, 

 flaring out to about 50 ft at the extreme outer end. Armor stone 

 slopes for the ocean and harbor sides were 1V:2.3H and 1V:1.5H, 

 respectively. Based on utilizing local stone, the cost of the work 

 was estimated to be $3,900,000. The design analysis used was the 



(Continued) 

 75 



