| Project/Area Number |
10480094
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Natural disaster science
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
TAKAHASHI Tamotsu Disaster Prevention Research Institute, Kyoto University Professor, 防災研究所, 教授 (40027230)
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| Co-Investigator(Kenkyū-buntansha) |
SATOFUKA Yoshifumi Disaster Prevention Research Institute, Kyoto University Researh Associate, 防災研究所, 助手 (20215875)
NAKAGAWA Hajime Disaster Prevention Research Institute, Kyoto University Associate Professor, 防災研究所, 助教授 (80144393)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥10,200,000 (Direct Cost: ¥10,200,000)
Fiscal Year 2000: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1999: ¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 1998: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | landslide / slip / liquefaction / debris flow / scale prediction / experiment / numerical simulation |
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| Research Abstract |
Recently in Japan, large scale debris flow that is induced by landslide often occurs. But, the discharge and the hazardous area of that kind of debris flow cannot be predicted, because, at the moment, there is no predictive model. This investigation aims to present a predictive model of viscous debris flow generated by a landslide.
Whether the debris flow is induced in contractive soils or in dilative soils may require different way of water supply that is necessary to fill up the void space among particles in debris flow. Here, the landslide is assumed to occur in dilative soil block by the appearance of saturated soil layer near the slip surface.
A test piece of dilative soil that contains plenty of water was prepared in a steep experimental flume, and it was released to move down slope. The lower saturated layer was liquefied by shearing, and it was left behind the soil block as debris flow. The soil block becomes thinner and thinner with its advance down the slope, and the total volume of debris flow left behind increases.
The speed of liquefaction was given as a function of water content and shearing rate, and a system of equations that describes the motion of the soil block was obtained. The validity of the theory was proved by comparing the theoretical results with experiments. Another system of equations that is able to predict not only the motion of soil block but the motion of debris flow even after stoppage of the soil block is obtained. The Harihara River debris flow that is a typical landslide induced debris flow will be reproduced numerically using the newly developed theory.
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