supply of dolosse and trilongs, and saw limestone units to simulate the 

 proposed 100-ton cubes. The jetty head and about 300 feet of the adja- 

 cent trunk section were reproduced, as accurately as possible, to scale. 

 An additional 1,000-foot reach of the shoreward trunk section was repro- 

 duced to ensure that the wave environment on the outer reaches of the 

 structure was reproduced properly. Since the stability of the 1,000-foot 

 reach was not in question, the reach was reproduced correctly only with 

 respect to its geometery and its wave reflective characteristics were 

 reproduced only approximately. The specific weight of the model water 

 was 62.4 pounds per cubic foot; the specific weight of the prototype 

 seawater was assumed to be 64 pounds per cubic foot. Also, the specific 

 weights of the model armor units were not the same as those of the pro- 

 posed prototype armor units. The relations between these variables, 

 model-to-prototype, were determined from equation (6-39). The weights 

 and specific weights of the armor units used in the model tests and the 

 corresponding prototype equivalents are given in Table 6-4. 



Table 6-4. Weights of armor units in model and prototype. 



Armor unit' 



Model 



Prototype 



Wa 



7a 



Wa 



Ta 





(lb) 



(Ib/ft^) 



(ton) 



(Ib/ft^) 



Cube 



1.62 



145.0 



100 



150 



Trilong 



0.50 



142.0 



28 



150 



Tetrapod 



0.49 



141.6 



28 



150 



Tribar 



0.43 



140.4 



23 



150 



Tribar 



0.62 



140.1 



33 



150 



Tribar 



0.80 



141.0 



44 



150 



Tribar 



1.13 



142.2 



65 



150 



Dolos 



0.58 



140.4 



32 



150 



Dolos 



0.90 



142.2 



51 



150 



Dolos 



0.90 



142.2 



45 



155 



Dolos 



1.00 



141.4 



56 



150 



Dolos 



1.00 



141.4 



43 



160 



' Details of the various types of armor units are described in Hudson (1974). 



The values of k^p and P in equations (6-40) and (6-41) , as determined 

 during the testing program, are shown in Table 6-5. 



(h) Test Procedures . The test sections were installed in 

 the flume so that the waves, which approached the structure with an angle 

 of incidence of about 45°, reflected from the test section and were dissi- 

 pated on the rubble wave absorber along the perimeter walls of the dif- 

 fraction basin. Average bottom slopes were used seaward of the jetty 

 head to approximate the prototype bottom contours. A Stillwater level 

 of +7 feet MLLW was used in all high water test conditions. This level 

 was selected based on MHHW level of +6.4 MLLW and a superimposed wind 

 setup of 0.6 foot. A Stillwater level of 0.0 foot MLLW was also used in 



390 



