EXPERIMENTAL STUDY ON WAVE OVERTOPPING REDUCTION PERFORMANCE OF BLOCK MASONRY SEAWALL

From the viewpoint of landscape and beach utilization, the crown height of seawalls should be as low as possible. Various types of low crown height seawall have been proposed. When there is a limit to expansion of seawalls to the front sea area, vertical block masonry seawalls are sometime applied. However, the shapes of wave-dissipating blocks vary, and comparisons of their overtopping characteristics have not been conducted. The purpose of this study is to clarify the effect of reducing wave overtopping on two types of block masonry seawalls comparing to vertical seawall. Results indicated that the wave-dissipating block masonry seawall with the diamond-shaped opening with the lid crown parapet can reduce wave overtopping under any conditions. In addition, calmness of the front sea area can be improved due to low wave reflection rate, and wave runup can be smaller than vertical seawall.