Experimental Study On Scour Funnel In Front Of Dam In The Sediment-laden River

There are serious sediment deposition problems in reservoirs built on sediment laden-laden rivers.The deposition of sediment not only reduce the reservoir’s capacity,but also gradually lose function of a reservoir.After the balance of the sedimentation,the scour funnel in front of the dam can keep the comprehensive benefits of the reservoir.the physical model of the reservoir is established in this experiment,which satisfies geometry resemblance,grain suspend resemblance,dynamic resemblance,grain kinetic resemblance and river bed transfiguration resemblance.According to the experiment of the scour funnel,the slope of the scour funnel in front of the dam in the sediment-laden river is studied.Several researches are carried out as follows:When the operating water level is 756 cm and the flow quantity is 3L/s,the scour funnel’s shape of different tunnels has been analyzed.Because of the limitation of the boundary,the slope of scour funnel formed by opening the deep drainage tunnel which near the the river is gentler than the slope of the scour funnel formed by opening the deep drainage tunnel which is far away from the river.When the operating water level is 756 cm and the flow quantity is 6L/s,the scour funnel’s shape of different tunnels has been analyzed.The test results show that the slope of scour funnel formed by opening two deep drainage tunnel is slightly gentler than the slope of the scour funnel formed by opening one deep drainage tunnel.When the flow quantity is 6L / s and the 1# tunnel is opened,the shape of scour funnel in different water level has been studied.When the operating water level is756 cm and the flow quantity is 6L/s,the shape of scour funnel when two bottom tunnels are opened has been studied.The test results show that the longitudinal slope of scour funnel is relatively gentle when the flow quantity is 6L/s.The slope of scour funnel formed by opening the deep drainage tunnel is slightly gentler than the slope of the scour funnel formed by opening one bottom drainage tunnel.When the 1# tunnel is opened and the water level is 756 cm,the shape of scour funnel in different flow quantity has been studied.The test results show that the slope of scour funnel when the water level was 756 cm is slightly gentler than the slope of the scour funnel formed when the water level was 768 cm.When the flow quantity is 3L/s,the vertical distribution of sedimentconcentration in different conditions at the power station has been studied.The test results show that the sediment concentration of the power station is less than the sediment concentration of the inflow.The sediment concentration at the surface is smaller than the sediment concentration at the bottom.Although the sediment concentration is different,the slope of the scour funnel which formed in front of the1# deep drainage tunnel is relatively steep.