Book Description

Tests of riprap stability under wave attack were conducted at prototype scale in the large wave tank at the U.S. Army Coastal Engineering Research Center (CERC). Wave heights ranging from 1.4 to 6 feet and wave periods ranging from 2.8 to 11.3 seconds, were used. Three embankment slopes, 1 on 1.5, 1 on 3.5, and 1 on 5, were tested. The riprap stone was a diorite placed on the embankments by dumping. The median stone weights of the riprap ranged from 27 to 120 pounds. The study showed that wave period, because of its influence on breaker characteristics, has a significant effect on riprap stability. Wave conditions which produce the lowest riprap stability are predictable and are associated with a collapsing-type breaker.