Stability of berm breakwater with reduced armor stone weight

Abstract

The basic principle involved in the design of S-shaped breakwater is the provision of a wide berm at or around the water level with smaller size armor stones than that used in conventional design, which are allowed to reshape till an equilibrium slope is achieved. An attempt is made to assess the influence of wave height, wave period, and berm width on the stability of S-shaped breakwater with reduced (30% reduction in armor stone weight) armor unit weight. From the investigation, it is found that the berm breakwater with 30% reduced armor weight would be stable for the design wave height if the berm width is 60 cm and wave period 1.2 s. For higher wave periods studied, zero damage wave height reduces by 20-40% of the design wave height. Wave period has large influence on the stability of berm breakwaters. The runup increases with decrease in weight up to Wo/W=0.9. 2004 Elsevier Ltd. All rights reserved.