Elucidation of deposition dynamics focusing on stress wave propagation of collapsed soil mass and sophistication of its evaluation methodology

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14239
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Toyohashi University of Technology
• Principal Investigator: Naito Naoto 豊橋技術科学大学, 工学(系)研究科(研究院), 助教 (10816200)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 急傾斜地 / 斜面崩壊 / 崩壊土砂 / 到達距離 / 衝撃力 / 応力伝播 / 粒状体 / 個別要素法

Outline of Final Research Achievements

We developed a simplified unsaturated DEM model incorporating ground adhesion and validated it by comparing with results from large-scale debris flow experiments, including deposition shape, sediment flow velocity, and wall impact pressure distribution. Using systematic and numerical experiments, we investigated the effects of parameters such as slope gradient, flow length, collapse volume, sediment size, and initial deposition volume on debris runout distance. Our analysis of sediment behavior and flow stability revealed the deposition dynamics of slope collapse, encompassing flow, impact, and cessation, with a focus on impact force transmission and its relationship to energy dissipation. We also proposed a novel evaluation method for runout distance and impact force based on energy dissipation.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

本成果は，斜面防災工の新技術開発や既存ストックの戦略的維持管理に貢献するだけでなく，連続体解析に用いられる土の挙動を記述する構成則の低拘束圧環境下の衝撃挙動への拡張，地盤工学分野における様々な衝撃現象の理解に貢献する．今後は，土－構造物の衝撃相互作用を考慮した地盤・構造・衝撃分野を横断する学際的研究課題への発展が期待されることなどから学術的創造性も高い．地盤工学と構造工学が分野超えて連携することで種々の衝撃制御への土や地盤力学の利用を拡大し，新たな地盤工学のパラダイムに繋がることが期待される．さらに，地盤工学の知見を発展させることで，他の工学への貢献も十分期待できる．