STUDY ON WAVE OVRTOPPING AT JOINT CORNER OF SEAWALLS BY HIGH TIDE AND HIGH WAVE

Abstract

 A slit caisson is one of the effective measures to reduce wave overtopping particularly if the height of a target seawall is limited, such as at airports. However, the performance of the slit caissons on the wave overtopping may not be sufficiently effective when the water chambers are submerged during high tides. And the quantitative evaluation of the effect has not been sufficiently studied. In particular, it is difficult to reduce the wave overtopping by only the slit caissons due to an increasing overtopping wave rate at the corner of the seawalls due to the convergence of waves. In this study, the height coefficient of the slit caisson is evaluated when its chamber is submerged in the water. And the variation tendency of the overtopping wave rate is investigated between the case of direct incidence and non-direct incidence of the waves against the corner. In addition, it is shown that the overtopping flow rate at the corner can be effectively suppressed by installing a simple wave return wall as an additional countermeasure to the slit caissons.