2023 Fiscal Year Final Research Report
Evaluation of hydraulic conductivity considering non-uniformity and compression creep of non-woven drainage fabric used for landslide prevention
| Project/Area Number |
21K04250
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 22030:Geotechnical engineering-related
|
|---|
| Research Institution | Shinshu University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
梅崎 健夫 信州大学, 学術研究院工学系, 教授 (50193933)
|
|---|
| Project Period (FY) |
2021-04-01 – 2024-03-31
|
| Keywords | 地盤工学 / 土砂災害 / 排水材 / 不織布 / 不均一性 / 透水係数 / 間隙比 / クリープ |
|---|
| Outline of Final Research Achievements |
(1) Quantitative evaluation of the non-uniformity of initial conditions: The non-uniformity of 1,200 non-woven geotextile specimens was evaluated using the average value and standard deviation. (2) Quantitative evaluation of compression characteristics: The long-term compressive creep characteristics can be evaluated up to 24 hours as primary compression and from 24 hours onwards as secondary compression. In 24-hour incremental loading test, the compression characteristics are almost the same in the dry and saturated conditions. (3) Quantitative evaluation of permeability: Regardless of the non-uniformity of initial conditions, the permeability can be determined by the void ratio. As an example, the change and distribution of the coefficient of water permeability normal to plane of dry non-woven geotextile under vertical stress was determined and visualized. It is suggested that a similar method can also be applied to the saturated condition and the coefficient in the plane.
|
| Free Research Field |
地盤工学
|
| Academic Significance and Societal Importance of the Research Achievements |
近年の想定を越える豪雨における土砂災害を防止することは喫緊の課題である．盛土内への浸透雨水を速やかに排水するために，土木用不織布が水平排水材として敷設されている．得られた結果に基づけば，圧縮応力がp=8kN/m2からp=553kN/m2に増加すると，透水係数は1/10程度に減少する．各圧縮応力における垂直方向透水係数の最大値と最小値の比は，約2倍程度であることを示した．これらの結果は，盛土内に浸透する雨水の浸透解析に用いるパラメーター，適切な敷設間隔や配置を決定する設計法の確立や局所的な浸透破壊の対策に必要なものであり，土砂災害防止に繋がる．
|
