WAVE SCOUR AROUND THE PILE-SUPPORTED WAVE ABSORBING BREAKWATER WITH LOW CROWN HEIGHT BY MOVABLE-BED MODELS

Abstract

  The study follows the investigation of the structure of the pile-supported wave absorbing breakwater with a low crown height, reported in 2009. In the present paper, wave scour around the structure is studied. The investigation was performed by movable-bed models. The equilibrium scour depth was larger than that of piles and the maximum scour was generated at offshore pile near the gap of the structure where the velocity of fluid was very high due to the contraction. Normalized maximum scour depth by incident wave height was in inverse proportion to Shields number. Also, the morphology in front of the structure showed as N-type scour which occurs in standing waves region. Moreover, a countermeasure against local scour was proposed and the validity was verified by hydraulic tests.