Systematization of scientific principle and formulae for designing hydraulic structures constructed with natural materials

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K06588
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Hosei University
• Principal Investigator: Michioku Kohji 法政大学, デザイン工学部, 教授 (40127303)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: 河川構造物 / 流体力 / 流量制御 / 貯留機能 / 透過流 / 自然浄化機能 / エネギー減衰 / 河床せん断力

Outline of Final Research Achievements

Along the paradigm of near-nature river work, structure tend to be constructed with natural materials. The present research is to highlight such nature-friendly river works focusing on hydrodynamics of vegetation or rock-arranged structures. First, a hydrodynamic model was devised for analyzing flow in vegetated channels like flood protection forests. Secondly, hydrodynamics were discussed for rock-arranged structures. Hydrodynamics of rubble mound structures were examined and theoretical solutions for water surface profile and discharge rating curve were validated in comparison with experimental data. Performance of the rubble mound structure for dissipating flow energy and removing pollutants were also discussed by applying the proposed model. Thirdly, an analysis was conducted to investigate flow fields in gravel-bed channels with alluvially meandering thalweg or with alternating sandbars, which provides information on self-purification performance of such channel works.

Free Research Field

工学

Academic Significance and Societal Importance of the Research Achievements

順応的管理を原則とする多自然川づくりでは経験豊富な技術者人材と現場状況に応じた科学的知見が必要である．技術界・河川管理を取り巻く人材・経済資源の厳しい状況を勘案すると，今こそ多自然川づくりの基本理念を学理構築と公式化に向かってシフトさせるべき時期にあり，本研究は川づくりのパラダイムに新たなマイルストーンを築く端緒となり得る．全ての課題が本研究の対象として網羅されたわけではないが，ここで示した個別課題への取り組み方法と公式体系に向けた開発手順により多自然川づくりの具体化と実装を図るための道筋が提示され，より多くの研究主体を巻き込んだ活動が今後に展開されると期待される．