| Project/Area Number |
12650497
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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 |
Geotechnical engineering
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| Research Institution | Matsue National College of Technology |
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Principal Investigator |
KAWAHARA Soichiro Matsue National College of Technology, Associate Professor, 助教授 (50169752)
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| Co-Investigator(Kenkyū-buntansha) |
MURO Tatsuro Ehime University, Faculty of Engineering, Professor, 工学部, 教授 (00025967)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | rockfall / impact / rock shed / sand cushion / slope gradient / simulation / motion constants / ratio of residual velocity to free fall / 敷砂緩衡材 / 衝撃力 / まさ土 / 室内実験 / 衝撃加速度 / 衝撃力伝達率 |
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| Research Abstract |
The estimates of the impact force caused by a rock fall and the falling point are very important for the design of rock fall prevention covers. Sand cushions against the impact force are widely used for rock fall prevention covers.
1. Effect of Dry Density of Sandy Soil to Impact Response Due to Rockfall
The objective of this study is to investigate the relation between the dry density of a sandy soil and the impact responses due to a falling weight likened to a rockfall. A series of laboratory experiments for a decomposed granite soil was executed in the combination of weight masses and drop heights.
As a result, it was clarified that the impact acceleration, the earth pressure at the bottom of the mold and the propagation velocity of the impact wave increase with the increase in the dry density of the soil. However, the transmission ratio of the impact force does not depend on the dry density of the soil.
2. Simulation on Line Motion of Rockfall on Soil Slope
The objective of this study is to develop a new simulation on line motion of a cylindrical
rockfall on a flat slope made of a homogeneous soil. A terramechanics theory concerned in a rigid wheel was applied to the simulation considered the sinkage of the rockfall.
As a result, it was clarified that the line motion of the rock fall is greatly influenced by the compaction resistance expressed as the component parallel to the slope of the normal soil reaction. Qualitative agreement between the calculated results and the measured values was obtained.
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