2 Monitoring Plan and Data 
The objective of the monitoring effort in the Periodic Inspections work unit 
was to establish base level data upon which long-term stability response of the 
Ofu Harbor breakwater could be defined through periodic inspections. The con- 
crete armor units on the outer 130-m-long (425-ft-long) portion of the breakwater 
were monitored. The monitoring plan consisted of targeting and ground surveys, 
aerial photography, photogrammetric analysis of armor units above the water- 
line, and ground-based broken armor unit surveys. 
Armor Unit Survey 
On 16 October 1996, a walking survey of armor units above the waterline 
was conducted on the outer 130-m (425-ft) portion of the Ofu Harbor break- 
water. The survey of the structure revealed no broken tribars. One sea-side 
tribar was slightly separated from the rib cap (Figure 11) at sta 3+05. On the 
Figure 11. Separation between tribar and rib cap 
Chapter 2 Monitoring Plan and Data 
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