and upper lakeside slope. Step 3 produced a slight increase in the severity 

 of in-place dolos rocking, but this was still only moderate in its severity. 

 Plan 1 was in good condition with only minor damage at the end of Hydrograph C 

 (Photos 17-19). All of the displaced dolosse had come from the harbor side of 

 the crown where, due to the random placement, some of the dolosse were not 

 interlocked with other dolos armor. 



20. Without rebuilding the dolos armor, the structure was exposed to 

 Hydrograph A. Mo additional dolos displacement occurred during Hydrograph A, 

 but the amount and severity of in-place dolos rocking showed a definite in- 

 crease on the crown and upper lakeside slope. The structure was in good con- 

 dition at the end of Hydrograph A (Photos 20-22), but the moderate to signifi- 

 cant in-place rocking observed during this test showed that there was a high 

 potential for possible dolos displacement and breakage. 



Plan 2, 2.3-ton Dolosse 



21. With the proposed 4- ton dolos design (Plan 1, Plate 1) proven to be 

 stable for the wave and swl conditions of Hydrograph C, NCB requested that 

 additional tests be initiated to determine the stable design wave height for 

 the existing 2-ton dolosse (Plan 2, Plate 2) on the east breakwater at Cleve- 

 land Harbor. 



22. The existing 2-ton dolosse on the east breakwater in Cleveland 

 Harbor could not be represented exactly in the model without changing the 

 existing model scale and recalibrating the test facility. At the existing 

 scale and with the available model dolosse, a 2.3-ton dolos with a specific 

 weight of 143 pcf could be represented. NCB thought this representation would 

 be the most cost-effective approach and results of these tests would provide 

 the information they required. 



23. The 2.3-ton dolos section (Plan 2) had a crown width of 13.0 ft at 

 an elevation of +10.3 ft lwd. Two layers of randomly placed dolosse extended 

 down to an elevation of -22.0 ft lwd on a 1V-on-2H slope. Plan 2 was exposed 

 to 8-sec nonbreaking wave heights of 8.5, 9.0, 10.0, 10.5, and 11.0 ft at an 

 swl of +4.9 ft lwd. Although no significant dolos displacement occurred, the 

 11.0-ft wave height produced significant amounts and degrees of in-place rock- 

 ing of the dolosse on the crown and upper lakeside slope. Wave heights below 

 this had caused only minor displacement and in-place rocking. The 2.3-ton 



14 



