Middle Breakwater Comprehensive Condition Assessment

The second comprehensive condition assessment of the Middle Breakwater was performed between 2010 and 2014 to provide the U.S. Army Corps of Engineers a basis for the planning of future repairs, maintenance, and improvements. The assessment indicated that the breakwater did not settle since construction and that the breakwater is vulnerable to the combined effects of waves, high water levels, and earthquakes. For the 12-foot (3.7 m) 100-year significant wave height, the 10-ton (9.1 metric ton) armor stone appears correctly sized. In a seismic event, the breakwater's clay and sand core could be susceptible to liquefaction and deformation. The breakwater provides adequate short wave protection to ships at berths anywhere in the port, except for service boats at Pier F. With a median annual frequency of failure of 0.0309, which translates to a return period of approximately 32 years, the wave hazard is the dominant hazard.