magnitude of armor unit breakage, which could compromise the integrity 

 of the structure. It included the collection of aerial photography, wave 

 and water level data, survey data to determine armor unit movement 

 above the waterline, an inventory of broken dolos units, time-lapse pho- 

 tography, and underwater surveys using both side-scan sonar and diver in- 

 spections. As evidenced by significant movement and breakage during 

 the monitoring study, the 1,814-kg (2-ton) dolosse appeared to be under- 

 designed. A total of 692 broken units were observed above the waterline 

 at the conclusion of the study. Subsequent to the monitoring, in the 

 spring of 1987, it was noted that most of the dolosse around the head of 

 the eastern end of the structure were missing. The damage was repaired 

 in May 1987 with 3,628-kg (4-ton) dolos armor units as opposed to the 

 1,814-kg (2-ton) units previously used. Several 3,628-kg (4-ton) dolosse 

 were also placed in low areas along the trunk to bring it back to the cor- 

 rect elevation. The east breakwater was monitored from July through No- 

 vember 1993 under the "Periodic Inspections" work unit of the MCNP 

 program. Monitoring consisted of limited ground surveys, low-altitude 

 aerial photography, photogrammetric analysis, and a broken armor unit 

 survey (Bottin, Marcus, and Mohr 1995). Very accurate armor unit posi- 

 tions on the breakwater were obtained as well as detailed topography and 

 point plot maps on the above-water portion of the structure. A total of 

 782 broken armor units indicated that the rate of breakage on the breakwater 

 had drastically decreased compared with the period after initial construction. 



The Cleveland Harbor east breakwater (Figures 42 and 43) was in- 

 spected on 7 October 1997. The inspection revealed that the structure has 

 changed little since the 1993 survey. Comparison of armor unit positions 



» 



Figure 42. View of 3,628-kg (4-ton) dolosse at head of Cleveland Harbor 

 east breakwater 



38 Chapter 2 Project Descriptions and Inspection Results 



