Elucidation of levee breach generation mechanism and flood flow behavior considering sediment concentration

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K04958
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 25030:Disaster prevention engineering-related
• Research Institution: National Institute of Technology, Toyota College
• Principal Investigator: Tanaka Takayuki 豊田工業高等専門学校, 環境都市工学科, 准教授 (70548437)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 河道湾曲流 / 破堤解析 / 高濃度流 / 開水路流

Outline of Final Research Achievements

Due to frequent heavy rain disasters, floods due to levee breaches are occurring frequently. Since it is difficult to predict where a levee will break, many studies have been conducted on levee breakage using various methods. The purpose of this study is to clarify the flow structure and occurrence of levee breaches in river channels with overflows, such as Shimizu flow and high-concentration sediment flow. As a result of the research, for curved flows with overflow, the tendency of the overflow start point is affected by the difference in the curvature radius, the larger the tangential angle, the larger the overflow range, was found to occur mainly. We also clarified the flow structure in fresh water and high-concentration flow with various boundary conditions such as piers and vegetation.

Free Research Field

河川防災学

Academic Significance and Societal Importance of the Research Achievements

湾曲部を伴う河道の流れ構造や破堤発生メカニズムを明らかにすることで，破堤箇所の想定がより容易となり，河道整備の優先順位を決定する上で重要な知見を得ることができる．
また，様々な流体粘性における流動機構を明らかにすることで，洪水時の実河川の流れ構造を予測するための知見を得ることができる．さらに，橋脚や植生などの境界条件を有する開水路流れの流れ構造を知ることで，洪水流の挙動についても予見することが可能となる．