Sophistication of numerical simulation of Tsunami wave with granular solids such as sea ice floes and risk analysis using computational intelligence

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04630
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: Public Works Research Institute
• Principal Investigator: Kioka Shinji 国立研究開発法人土木研究所, 土木研究所(寒地土木研究所), 総括主任研究員 (20414154)
• Co-Investigator(Kenkyū-buntansha): 竹内 貴弘 八戸工業大学, 大学院工学研究科, 教授 (40305983)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 海氷 / 津波 / パイルアップ / アイスジャム / 人工知能 / 数値シミュレーション / 個別要素法 / 破壊

Outline of Final Research Achievements

Tsunamis with sea ice floes have been reported to cause serious damage to private houses and bridges from the impact of the ice floes (e.g., in the 1952 Tokachi-oki earthquake). In this study, we performed model experiments involving onshore run-up of a tsunami containing sea ice floes with a focus on ice jams and pile-up formations between structures, and on a large accumulation of sea ice on the road that plays important roles for relief activities. We developed an estimation method of the pile-up height, which could be useful in the estimation of safety evacuation levels and the elimination of lots of sea ice on the road. These experimental results were also learned by using neural network to incorporate in one of computation modules of our numerical simulation system of tsunami with ice floes, which is a part of very complicated mathematical model. We proposed one of tools which would be useful in the formulation of disaster mitigation plans including hazard maps.

Free Research Field

氷工学

Academic Significance and Societal Importance of the Research Achievements

流氷や沿岸結氷板を含む氷海域において，大量の海氷をともなった津波は，被害を拡大し，国民の生命・財産に甚大な損害を与える．過去に，津波とともに海氷が遡上し，建築物等が損壊した事例が幾つか報告されている．本研究成果は，海氷を伴う津波に対する，危険物や避難施設などの重要構造物の配置計画や避難行動計画等に役立つハザードマップ作成のほか，重要構造物に作用する津波と海氷による混相流の外力推定やその安定性・崩壊危険性等の照査といった安全性評価に役立つものである．さらに，救助や復旧・経済活動に重大な影響を及ぼす道路への海氷や漂流物の堆積メカニズムの把握や対策，道路啓開上の留意点等に資するものである．