A Flaring Shaped Seawall (FSS) can drastically reduce a crest height and waveovertopping quantity in comparison with a conventional upright one. In this study, systematic hydraulicexperiments by irregular waves were carried out using a two-dimensional flume. As a result, a diagram to estimatethe crest height and overtopping rate of the FSS was made, and it is found that the overtopping rate and reflectioncoefficient of the FSS are almost similar to those of an upright seawall covered with wave-dissipating blocks.Furthermore pressures by regular waves were compared with ones by irregular waves, and a wave force formula for theFSS in an extreme shallow sea was investigated.

A Flare Shaped Seawall (FSS), the shape of which is an overhanging circular arc, can drastically reduce the crest elevation and wave overtopping amount in comparison with a conventional vertical one. However, it is thought that impulsive wave pressures are more likely to act on the surface of the FSS in rough seas. In this paper, a wave dissipating structure which reduces wave pressures and maintains the ability to prevent wave overtopping is investigated experimentally using a water channel. It is found that a combination of slit type columns in the FSS and wave dissipating blocks, located a little away from the FSS and the height of which coincides with the water surface, is suitable.

A Flaring Shaped Seawall (FSS), a new type of one, can drastically reduce a crest height and wave overtopping quantity in comparison with a conventional upright one . The FSS will usually be set on a mound from the point of a cost of manufacturing and construction . Thus, in this paper, effects of the mound on hydraulic characteristics of the FSS (a wave overtopping rate , a wave run-up height and a reflection coefficient) are clarified from experiments using a two-dimensional flume . Furthermore a method for the FSS on the mound is proposed, and it is shown that the method is adequate under the condition of experiments in this paper.

A Flaring Shaped Seawall (FSS) can make reduce crest height rather than conventional seawall in rough sea. However, the FSS has not been sufficiently made a study of application for road seawall in the neighborhood of shoreline. In order to clarify the hydraulic characteristics of the FSS as road seawall in that sea, two-dimensional wave experiments were carried out, and wave run-up height, overtopping rate, pressure distribution and others were measured. It is confirmed that the characteristics of the FSS are more superior to the vertical wall, and that are almost similar to the vertical wall protected with block mounds. So it is found that the FSS is suited to road seawall without wave-dissipating blocks.