Formation of Breaking Bores in Fukushima Prefecture Due to the 2011 Tohoku Tsunami

Abstract

Tsunami forces on critical coastal structures were reanalyzed by combining laboratory experiments and numerical tsunami simulation, focusing on the formation of breaking bores and their large force to structures. Laboratory experiments demonstrated that nearshore tsunami is likely to form a breaking bore when the slope of the incident tsunami front is steep and the nearshore bed slope is mild. The impulsive pressure to coastal structures was found to increase with the steepness of the tsunami front. Based on these results, together with numerical simulation of tsunami, the formation of bores was discussed in relation to coastal cliff topography in Fukushima Prefecture.