Abstract
Trapping mechanism of floating objects during tsunami due to aligned trees was investigated through field surveys and hydraulic experiments. From the hydraulic experiment, the physical factors related to roadside trees and explaining the capture of floating objects were obtained. In addition, we show the maximum momentum limit at which trees fall when floating objects were trapped. Using the floating objects capture evaluation method of the trees that considered falling of trees, a verification case was performed knowing the specifications of the trees and floating objects in Tagajo city in case of the 2011 Tohoku earthquake and tsunami. We proved that the trees in Tagajo city did not fall even if it trapped floating objects during tsunami, generally agreeing on the quantity of the trapping ratio.
