2013 Fiscal Year Final Research Report

Proposal for prevention strategies against the enlarged turbidity currents

Research Project

Project/Area Number	23651181
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Natural disaster science
Research Institution	Osaka Prefecture University
Principal Investigator	BABA Nobuhiro 大阪府立大学, 工学(系)研究科(研究院), 教授 (10198947)
Project Period (FY)	2011 – 2013
Keywords	土砂災害 / 防災 / 乱泥流 / 重力流 / 計算流体力学
Research Abstract	This study proposes the practical methods of controlling the turbidity currents and the strategies to protect human properties in the serious disasters which have been more frequently brought about by heavy precipitation extraordinarily concentrated in some local mountainous areas due to global warming. We carried out the experiments using a small inclined tank and the computations based on the finite volume solution of the Navier-Stokes equations for such enlarged turbidity currents. The results indicate that the interaction of the currents with the obstacles certainly reduces the rate of energy supply to the head from the latter part of the current by dividing the powerful head with a large amount of the mass and energy into the upper and lower parts. It is found that as a result even the system of horizontal flat structures away from the bottom has considerable effects to depress the destructive impact force without any burden on the environment.