2019 年 25 巻 p. 469-474
In the past researches, the authors conducted a moving bed experiment on a block type groundsill with a flexible structure assuming that the downstream riverbed is decreasing. As a result, with the lowering of the water level downstream, the high flow velocity acts on the bed protection mattress at the downstream end, and the block is swept away and the deformation extends to the main body. In this study, the fixed bed hydraulic experiment was carried out using the structure under the same conditions, and the flow field was measured around the mattress at the downstream end, which is the sudden change current field. On the basis of this result, we will consider the method of setting the fracture limit external force in the design and maintenance of the same type groundsill under the condition of riverbed lowering.
