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The uncoated nylon material deteriorated after 1-year exposure to sunlight 

 and was torn by handling equipment during breakwater construction. Wet 

 material was slippery and trapped air. When filled with sand, the smooth, 

 rounded bags, sometimes cushioned by an air bubble, failed to interlock 

 adequately to prevent motion under the least severe wave condition. Bags were 

 accurately dropped into place during wave action to construct one of the 

 submerged breakwaters. 



During testing, the structures' configurations changed drastically, 

 primarily from movement of bags during the first wave attack of the least 

 severe wave condition and during the steepest wave condition. The two high- 

 est submerged breakwaters lost whole layers of bags from their crests, and 

 the seaward face of the emergent breakwater slumped from a slope of 1 on 3 

 to a slope of 1 on 5.3. As wave conditions changed, scour and accretion 

 occurred alternately at the breakwaters' toes, but caused no measurable 

 settlement. The emergent breakwater and the highest submerged breakwater, 

 the two producing greater than 30 percent wave attenuation, underwent the 

 most wave-induced damage. 



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