NUMERICAL ANALYSES OF HYDRAULIC CHARACTERISTICS FOR TSUNAMI OF THE FLARING SHAPED SEAWALL

Abstract

 Authors have advanced the research and development concerning the flaring shaped seawall. Hydraulic characteristics that the wave overtopping rate can be greatly decreased though this seawall is a low crown height have been clarified. The first local construction is executed the flaring shaped seawall as a shore protection works against storm surge and waves in 2004 and, up to now, has been constructed about ten seawalls. However, many seawalls had damaged by the 2011 Tohoku Earthquake off the Pacific coast and we had to evaluate hydraulic characteristics to tsunami of the flaring shaped seawall.
 In this study, we have verified hydraulic characteristics to tsunami of the flaring shaped seawall by using the numerical analysis and have compared with it of the upright seawall and the sloping seawall. As a result, the flaring shaped seawall is able to clarify that there is a possibility that the impact wave force given to the structure in seawalls back is able to be decreased greatly according to the condition of tsunami and others.