Design method considering drainage for Embankment slope reinforced by gabions

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06495
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geotechnical engineering
• Research Institution: Nihon University
• Principal Investigator: Sento Noriaki 日本大学, 工学部, 教授 (40333835)
• Co-Investigator(Kenkyū-buntansha): 清原 雄康 八戸工業高等専門学校, その他部局等, 准教授 (20369911) ; 海野 寿康 宇都宮大学, 地域デザイン科学部, 准教授 (50570412)
• Research Collaborator: KUBO Mikio
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ふとんかご / 地盤 / 盛土 / 斜面 / 排水 / 補強

Outline of Final Research Achievements

Gabion, which is a wire mesh box filled with stones, is well known for practical engineers as the countermeasure for slope reinforcement of embankment. In this study, field tests for embankment with and without gabions were carried out to obtain basic data for rational design of countermeasures using gabions. Field measurement was conducted for 1 year to evaluate the effect of seepage due to rainfall. In the following test, reservoirs were constructed at the top of embankments to supply more water in the ground and lead to slope failure. Water contents in the embankment are measured and damages of slopes are observed in these tests.
Water content at the vicinity of lower gabion becomes smaller than that at the vicinity of foot of slope without gabions due to drainage. Failure occurred at the foot of slope in the embankment without gabions. On the other hand, no failure occurred in the embankment with gabions, it is found that reinforce effect of gabions for slopes.

Free Research Field

工学

Academic Significance and Societal Importance of the Research Achievements

斜面対策技術として古くから広く普及しているふとんかごについて、これまで実務者が暗黙知として認識していた対策効果を、実験結果に基づいてそのメカニズムを明らかにすることで形式知としたことに意義がある。具体的には、盛土崩壊の起点となる斜面下部において、排水と補強を両立できる合理的な対策方法であることが確認できた。さらに、今回の実験結果について数値解析によるケーススタディを重ねることで、対策効果を踏まえた合理的な設計方法の確立に寄与するものと期待される。