Fundamental study on management of groundwater drainage works for landslide mitigation
| Project/Area Number |
17580217
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | National Agriculture and Food Research Organization (2006)
National Institute for Rural Engineering (2005) |
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Principal Investigator |
OKUYAMA Takehiko National Institute for Rural Engineering, Department of Geotechnical and Hydraulic Engineering, Head of Laboratory, 農村工学研究所・施設資源部, 研究室長 (20343767)
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| Co-Investigator(Kenkyū-buntansha) |
ARIYOSHI Mitsuru National Institute for Rural Engineering, Department of Geotechnical and Hydraulic Engineering, Researcher, 農村工学研究所・施設資源部, 研究員 (10414442)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | landslide / groundwater drainage works / borehole / land disaster / 減災 / 防災 / 地下水排除 / 水抜きボーリング |
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| Research Abstract |
Observations of runoff from groundwater drainage works in relation to groundwater flow system were conducted on landslide slopes in the area of crystalline schist in Shizuoka Prefecture and pyroclastic flow deposit plateau in Miyagi Prefecture. Landslide mitigation measures had been completed mainly by groundwater drainage works for both areas. A borehole camera and a newly developed water sampler were used for partial water sampling in collecting pipes on the crystalline schist slope. A plenty of water of lower electric conductivity and higher dissolved oxygen flowed into the collecting pipe where the collecting pipe penetrated a groundwater vein stream detected by underground temperature survey method. Groundwater vein streams play a major role at the hydrological cycle. Groundwater drainage facilities should be planned after consideration of groundwater vein streams. Excess groundwater flowing beyond the drainage borings at the upper part of the slope was drained by the drainage borings at the middle part of the slope in a heavy rain. Water channels with high permeability were found to carry out sink function in the ground by measurement of water head at arbitrary depths using specially partitioned boreholes.
As a result of working rain analysis method for the landslide slope on a pyroclastic flow deposit plateau, groundwater head at the depth of 6 meters was lowered more than 1 meter than that before construction of the drainage facility and it brought the increase in safety factor from 1.12 to 1.23. Changes in groundwater head at the cultivation layer in farmland was not found.
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Report
(3 results)
Research Products
(7 results)
