Proposal of selection methods and compaction standards of levee body material suitable for river levee in cold regions

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06484
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geotechnical engineering
• Research Institution: Kitami Institute of Technology
• Principal Investigator: NAKAMURA dai 北見工業大学, 工学部, 准教授 (90301978)
• Co-Investigator(Kenkyū-buntansha): 川口 貴之 北見工業大学, 工学部, 准教授 (20310964) ; 川尻 峻三 北見工業大学, 工学部, 助教 (80621680)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 河川堤防 / 積雪寒冷地 / 凍上 / 融解 / 細粒分含有率 / 締固め / 植生工

Outline of Final Research Achievements

In this study, the effect of cold climate, especially frost heaving phenomenon, on river levees was investigated by field investigation, indoor test, and model experiment.
Field surveys confirmed that river levees were damaged by frost heaving in cold, low-snow areas. In addition, from the frost heave tests, it was found that the risk of levee damage on frost heaving increases when the fine fraction content of the levee body material increases. In addition, the model experiments revealed that increasing the degree of compaction of the levee body can increase the time until the levee breakage, but it was also clarified that the difference in water permeability of the supporting ground may accelerate the levee breakage. Finally, from the shear strength tests, it was confirmed that the vegetation works were effective as a means of reinforcing the levees in the cold regions.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

河川堤防の凍結深さおよび凍上量を計測した報告例はほとんどないことから，本研究の成果は河川堤防の凍上による脆弱化に関する基礎資料として貴重である。さらに，河川堤防の設計・管理基準は温暖な地域を対象として作成されたものがほとんどであり，寒冷地の堤防に必要な強度と遮水性，さらには耐凍上性を併せ持った寒冷地仕様の設計・管理基準を検討する場合に，本研究の成果は有用である。以上の成果は，寒冷地域の施工技術者からのニーズに応え，周辺地域の寒冷地河川防災に大きく貢献できると考えられる。