| 摘要 |
PURPOSE:To prevent or reduce noise caused by overflow water and also the vibration of the dam by preventing the warping of a rigid plate by the overflow water by providing a flexible film bag between the flexible film cover and the rigid plate fixed at the top of the flexible film cover. CONSTITUTION:One end of a plate 2 having a rigidity great enough not to be folded is fixed to near the position to be two-folded when fallen of a flexible film cover 1 over the whole length or partly in the direction of crossing the flow of river water. The other end is freely set without being fixed to the river bed by extending it in such a way that the slope formed by the plate toward the fixed portion to downstream side when rising the sam becomes a gentle slope. Also, a flexible film bag 3 is fixed in the direction of crossing the flow of river water on the river bed on the downstream side of the plate 2. When air (or water) is charged into the dam through air (or water) supply tubes 4 and 4', the flexible film cover 1 and the flexible film bag 3 are expanded and the bag 3 comes into contact with the lower face of the plate 2 to prevent the warping of the plate, whereby reducing noise due to the falling of overflow water. |
