| Project/Area Number |
13660248
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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 | University of the Ryukyus |
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Principal Investigator |
KOMIYA Yasuaki University of the Ryukyus, Faculty of Agriculture, Lecturer, 農学部, 講師 (60101466)
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| Co-Investigator(Kenkyū-buntansha) |
SHINJO Toshiya University of the Ryukyus, Faculty of Agriculture, Professor, 農学部, 教授 (40045109)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2002: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 2001: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | mudstone / cutting slope / slope protection work / slope failure / weathering / discontinuous plane / shear strength / maintenance / せん断抵抗 |
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| Research Abstract |
It investigated actual condition on transformation state and slope failure on the cutting slopes in the Neocene Shimajiri mudstone zone in Okinawa Island. Main results are as follows.
1. Mudstone cutting slope created in the agriculture farming village is 20m height or less, and there are many results of protecting the slope surface using concrete block retaining wall and vegetation.
2. It tended to mainly generate the slope failure in the slope where a passed year from the construction was long, and in the slope with slope protection work of open type than closed type. As the result, it was indicated that the slope failure was related to the degradation of the slope.
3. The cutting slope becomes easy to failure when the rain falls over 100mm per a day and the generation number of slope failure increases, as connected amount of rainfall is more abounding. It was indicated that existence of discontinuous plane such as the small fault and infiltration of rainwater were related to the slope failure.
4. The slope failure which arose in construction post-17th was assumed that a potential discontinuous plane in mudstone layer loosened by the cutting and rainwater invaded there, and water pressure increased, and shear strength decreased in the discontinuous plane.
5. It seems to be possible to reduce the generation of the slope failure, if the slope is checked prior to Rainy season and typhoon, and the abnormal position are urgently restored, and prevention from entering of the rainfall to the slope and drainage promotion of spring water from the slope is carried out.
6. They may be able to predict the danger of the slope failure by automatically observing ground water level and displacement of the ground using the investigation borehole prior to the construction.
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