| 摘要 |
PURPOSE:To prevent the occurrence of noise as well as secure the sufficient effluence capacity of a gate by a method in which a siphon-type water channel is provided from the middle of the upstream side of the gate door to the downstream side through the upper end and water sucked up from the middle of the upstream side is discharged to the downstream side. CONSTITUTION:The door 1 of a falling gate is supported in a freely rising and manner on a bearing (not illustrated) provided to the river bed 2 by using a shaft 4, and a siphon-type water channel 5 of an angular cross section is provided bendwise from the middle of the upstream side of the door 1 to the downstream side through the upper end. When the water level on the upstream side rises under the condition that the door 1 is in maximumly risen state, water flows into the water channel 5 from an inlet 8, and the water level in the water channel 5 rises as the water level on the upstream side rises. When the water level exceeds the horizontal line L, overflow starts inside the water channel 5 and water coming from the inlet 8 is discharged from an outlet 6. When the water level is further raised, the water channel 5 also becomes filled with water from the lower side, a siphonic action starts, and effluent amount is abruptly increased. However, noise caused by falling of water does not occur because of small head. |
