Table 2 (Continued) 



Date(s) Construction and Rehabilitation History 



seaward end of the north jetty was completed in 1961 and within the 

 year was undermined by wave action resulting in part of the mono- 

 lith breaking off. The monolith was repaired by placing rocks 

 around the head section on 1V:2H side slopes and grouting the rocks 

 with concrete. The elevation of the concrete at the north jetty 

 was raised to +25 ft mllw and at the south jetty to +26 ft mllw at 

 the tip. The heads were protected with 12- ton stones with a cover 

 layer of 100-ton concrete blocks. 



1963- Winter storm waves washed away most of the newly placed 100- ton 

 1965 concrete blocks. 



1969- The concrete monolith at south jetty was undermined and broken. 

 1970 Heads of both jetties were totally destroyed. 



1971- Rehabilitation of both jetties was completed. Concrete monoliths 



1972 were reconstructed, and 42-ton dolosse were placed around the sea- 

 ward quadrant of both jetty heads. Four unreinforced, 1,271 steel- 

 reinforced, and 17 steel-fiber-reinforced dolosse were placed on 

 the north jetty; and 22 unreinforced and 1,423 steel-reinforced 

 dolosse were placed on the south jetty head. Dolosse (43-ton) also 

 were placed on the shoreward transition sections of both jetty 

 heads. Two layers of dolosse were placed using a concentration of 

 11 dolosse per 1,000 sq ft of slope. Cost of this work was 

 $10,108,764. Model testing was conducted prior to these repairs 

 (Davidson 1971). 



1973 South jetty repairs using concrete and stone were completed at a 

 cost of $20,400. 



1975 An earthquake of 5.2 magnitude on the Richter scale occurred near 

 the site. Inspection trips subsequent to the earthquake revealed 

 fresh cracks along the south jetty running along the edges of the 

 crest and slope for a distance of about 800 ft on the channel side 

 and 300 ft on the seaward side. Blowout holes also were observed 

 at several locations on the south jetty. On the north jetty, three 

 of the dolosse had moved about 50, 100, and 150 ft from the place- 

 ment area, respectively. Only minor settling of the remaining 

 dolosse had occurred, and no cracking or unraveling of the dolos 

 units was apparent. 



1977 South jetty repairs using concrete and rock were completed. Ap- 

 proximately 15,000 tons of stone ranging from 1 to 20 tons were 

 used for these repairs. 



1977- The jetties were subjected to severe storms combined with high 



1978 tides and winds. On occasion, waves covered both jetties over 

 their entire lengths. Waves also were observed breaking over the 

 dolosse and concrete monoliths of the jetty heads. North jetty 

 repairs using stone were completed at a cost of $450,000. 



(Continued) 

 19 



