Round gate water retaining structure of dam blow-off pipe

The utility model discloses a dam blow-off pipe circular gate water retaining structure which comprises a dam and a blow-off pipe embedded in a dam body of the dam, a vertical access door groove is formed from the position, where the blow-off pipe is arranged, in the dam to the top of the dam, and the blow-off pipe intersects with the access door groove; a round gate is arranged at the intersection of the access door groove and the water discharging pipe for water retaining; an annular rubber water stop is arranged on the downstream face of the circular gate 3-6 cm away from the edge, and a lifting lug is arranged on the top of the circular gate. According to the utility model, pipelines in the dam can be blocked under the condition that a reservoir has water, and the technical problem that a gate valve or a steel pipe behind a dam blow-off pipe of the dam cannot be maintained, replaced and constructed is solved. 本实用新型公开了一种大坝放水管圆形闸门挡水结构，包括大坝及在大坝的坝体内埋设的放水管，在大坝内布置放水管的位置至大坝坝顶设置竖向的检修门槽，放水管与检修门槽相交；在检修门槽与放水管相交处设有圆形