Applicability evaluation of water repellent soil to the sand layer of capillary barrier

• Project/Area Number: 16K18149
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Geotechnical engineering
• Research Institution: Okayama University
• Principal Investigator: Kim Byeongsu 岡山大学, 環境生命科学研究科, 助教 (90648601)
• Research Collaborator: TAKESHITA Yuji ; KATO Shoji
• Project Period (FY): 2016-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: キャピラリーバリア / 疎水性地盤材料 / 保水特性 / 室内模型実験 / 限界長 / 浸透流解析 / 非側方流動性 / 遮水特性 / キャピラリー・バリア / 連続加圧方式 / 水分特性曲線 / 親水性地盤材料 / 河川堤防 / ヒステリシス / 疎水材 / 不飽和土 / 斜面

Outline of Final Research Achievements

In recent years, ground disasters such as the collapse of soil structure due to rainfall infiltration have frequently occurred. Preventing the rainfall infiltration from the surface layer of the ground would lead to the safety of the soil structure. The capillary barrier (CB) system formed by a sand layer and a gravel layer at the lower part has an impermeable function. This study focused on the water repellent soil in order to improve the impermeable function of the CB. In order to evaluate the applicability of water repellent soils capable of preventing from the rainfall infiltration to the CB, the laboratory model tests and infiltration analysis of the CB were performed according to rainfall conditions. It was confirmed that the impermeable function of the CB against rainfall infiltration was greatly improved. Thus, it can be said that the application of water repellent soils to the CB would be helpful for the safety of the soil structure against rainfall infiltration.

Research Products

• [Presentation] Characterizing water retention capacity of non-wettable soils using continuous pressurization method (2018)
  • Author(s): Kim, B.S.
  • Organizer: 7th International Conference of Unsaturated Soils
  • Int'l Joint Research
• [Presentation] Applicability evaluation of water repellent soil to the sand layer of capillary barrier (2018)
  • Author(s): Kobayashi,H.
  • Organizer: 5th Japan-Korea Joint Workshop on Unsaturated Soils
  • Int'l Joint Research
• [Presentation] キャピラリーバリアの被覆層における疎水材の適用性の検討 －その1: 疎水材の物理・保水特性－ (2018)
  • Author(s): 金 秉洙
  • Organizer: 第53回地盤工学研究発表会，地盤工学会
• [Presentation] キャピラリーバリアの被覆層における疎水材の適用性の検討 －その2: 室内模型実験の実施－ (2018)
  • Author(s): 小林 弘昌
  • Organizer: 第53回地盤工学研究発表会，地盤工学会
• [Presentation] キャピラリーバリアの砂層における浸透水の非側方流動性を考慮した解析的研究 (2018)
  • Author(s): 金 秉洙
  • Organizer: 全国大会 第73回年次学術講演会，土木学会(III)