| Project/Area Number |
14560115
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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 |
林学
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
SHUIN Yasuhiro The University of Tokyo, Graduate School of Agricultural and Life Sciences, lecturer, 大学院・農学生命科学研究科, 講師 (60221305)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Masakazu The University of Tokyo, Graduate School of Agricultural and Life Sciences, professor, 大学院・農学生命科学研究科, 教授 (10144346)
HOTTA Norifumi The University of Tokyo, Graduate School of Agricultural and Life Sciences, assistant, 大学院・農学生命科学研究科, 助手 (00323478)
TANAKA Nobuaki The University of Tokyo, Graduate School of Agricultural and Life Sciences, assistant, 大学院・農学生命科学研究科, 助手 (10323479)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | forest clear cutting / shallow slope failure / soil strength / finite elements method / slope safety factor / monitoring system / 森林皆伐斜面 / モニタリングシステム / 森林皆伐跡地斜面 / 飽和・不飽和浸透 / 気象・水文モニタリング / 画像モニタリング / インターネットカメラ |
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| Research Abstract |
The purpose of this research is to evaluate the influence of forest clear cutting on a occurrence of shallow slope failure with the monitoring system on actual natural sloe and numerical analysis. In addition to the real-time monitoring of slope condition at the moment of occurrence of slope failure, long term monitoring of change of soil strength and soil moisture with forest clear cutting is necessary to clarify the process of slope failure occurrence.
In this study, the forest clear cutting slope of the Tokyo University forest in Chiba is selected as the research object. This slope is installed monitoring system as follows
(A) Image monitoring system with web camera, (B) Monitoring system of incline of slope soil layer, (C) Weather and Hydrological monitoring system (rainfall, wind velocity, soil moisture, ground water level).
The results of application of monitoring system shows that the soil moisture condition level of lower part of the slope is going up comparison with the soil moisture condition of forest standing slope. Soil strength is evaluated with the direct shear test. The result of direct shear test shows that both of cohesion force and internal angle of the soil is reinforced by the root system.
With the results of application of monitoring system and shear test, Slope safety factor is calculated with the finite elements method Slope safety factor is rapidly decreasing with the increasing of ground water level, and Concentration of shear strain of the slope layer is emerging the foot part of slope.
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