EFFECTS OF BIMODAL ARTIFICIAL REEFS ON WAVE ATTENUTION AND BEACH STABILITY AT KIN-EICHO COAST, NIIGATA

Abstract

 This study on bimodal artificial reefs under construction at Kin-eicho coast of Niigata evaluated about wave attenuation by wave observation and beach stabilizing effect by bottom sounding.
 The comparison result suggests that wave height transmission coefficient of bimodal artificial reefs has higher tendency than the general artificial reef at Ariake coast because the crown width of bimodal artificial reefs at Kin-eicho coast are shorter. However, wave height transmission coefficient of bimodal artificial reefs satisfies a requirement of below coefficient of 0.6 required runup height against design wave.
 Effects of beach stability by bimodal artificial reefs have not been confirmed at the moment. The cause is due to the rapid flow offshore with sand from undeveloped section of bimodal artificial reefs.