EXPERIMENTAL STUDY ON THE INFLUENCE OF SUSPENDED SILT AND SAND ON TSUNAMI FORCE

Abstract

 When tsunami contains sediments, its wave force become strong due to increase of its density. This has a great influence on building damages. The sediment diameter collected from the tsunami at the time of the 2011 Tohoku-oki earthquake remained in Kesennuma City, Miyagi Prefecture was 6.74 µm, which is classified as silt. Tsunami wave force which contains sand sediments or silt has not been investigated. In this study, we conducted laboratory experiments on tsunami containing sediment. We then showed the tendency by investigating wave force, coefficient of wave pressure, angle of water surface, and its density. As a result, when density of tsunami was increased, it is likely that tsunami wave force become high and angle of wave front become variable when tsunami collides with vertical wall. We also showed that it is likely that wave pressure of tsunami is relatively increased when tsunami contains sediments even if Froude number is same.