2019 Fiscal Year Final Research Report
A Study on establishment of landslide early warning system considering stress history of slopes in Indochina Countries
| Project/Area Number |
17H04584
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 海外学術 |
|---|
| Research Field |
Geotechnical engineering
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
立川 康人 京都大学, 工学研究科, 教授 (40227088)
北岡 貴文 京都大学, 工学研究科, 助教 (40741583)
小林 晃 関西大学, 環境都市工学部, 教授 (80261460)
|
|---|
| Project Period (FY) |
2017-04-01 – 2020-03-31
|
| Keywords | 地盤工学 |
|---|
| Outline of Final Research Achievements |
It was revealed that the in-situ SWCC, which shows the correlation between suction and volumetric water content, is divided into three portions, the macro-pore flow dominant portion, the transition portion, and the matrix flow dominant portion, with the pore-water pressure as the threshold value. Among these, the in situ SWCC of the matrix flow predominant portion is similar to the conventional theory of unsaturated soil because it is corresponding to the behavior in a quasi-equilibrium condition. On the other hand, since the in-situ SWCCs in the other two portions, which are in the low suction state, are corresponding to behaviors in a non-equilibrium condition so that there is no unique relationship between the suction and the volumetric water content, they could not be explained by conventional theory. Then, it was clarified that the macro-pore flow may accelerate the formation of the pseudo-saturation region so that the macro-pore flow may induce the shallow landslide.
|
| Free Research Field |
地盤工学
|
| Academic Significance and Societal Importance of the Research Achievements |
当該斜面における物理探査結果により得られた知見として、高密度電気探査結果での比抵抗分布より浅層部（深度1.0m程度）の地盤構造を解明するためには、電極間隔を短くすることに加えて、比抵抗値の主要パラメータが飽和度であることから、乾季と雨季における探査結果での比抵抗分布の差分を用いることが有効であることを明らかにした。
次に、原位置計測結果において、本研究では、高強度降雨に対する間隙圧・体積含水率が急変する現象を選択流の概念に準じて，土中水の移動をマトリックス部とマクロポア部の流れに分離して検討を加えた結果、同現象は、マクロポア流に起因することを明らかにした．
|
