1997 Fiscal Year Final Research Report Summary
A study on the prevention of bed material scouring with porous protection work
| Project/Area Number |
08680488
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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 |
Natural disaster science
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| Research Institution | Setsunan University |
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Principal Investigator |
SAWAI Kenji Setsunan University, Faculty of Engineering, Professor, 工学部, 教授 (70109073)
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| Project Period (FY) |
1996 – 1997
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| Keywords | gravel bed protection work / rich-in-nature river work / vane work mild slope bank / bend channel / 緩傾斜河岸 / 弯曲水路 |
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| Research Abstract |
There are some methods for river bed and bank protection. Recently, in view of ecological preservation, porous protection work is noticed. It is preferable to keep big pores in order to maintain the habitat. However, it is apt to be suffered from scouring.
In this study, it is tried to protect the stream bed with multi-layr gravel sheet, whose diameter reduces downwords. The total thickness of the gravel layrs can be reduced by selecting the suitable combination of gravel size and thickness of the respective layr.
On the other hand, it is also important to reduce the tractive force itself in order to prevent bed and bank scouring. In this study, it is tried to apply vane work for the protection of mild slope bank in a bend channel, where, bank erosion occurs without any protection.
In the experiment using the submerged vanes with the height, length, spacing and angle selected to min : mize the scouring in case of rectangular channel with non-erodible bank, bank erosion was not reduced. By increasing the vane height up to water surface and changing the angle from negative to positive, bank erosion was much reduced, but local scouring around vanes increased. By increasing the length and spacing of vanes, both of bank erosion and bed scouring were reduced.
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