Experimental Study On The Law Of Water And Sediment Movement In Sediment Discharge Channel

In recent years,the problem of serious sediment deposition in irrigation channels is often encountered in the diversion of water from sandy rivers.The main measure to deal with this problem is to set up a sedimentation basin.However,the low-lying land suitable for the construction of a sedimentation basin has been used up,so it is urgent to find a new way to solve the problem of sediment deposition in the channel.In the previous research,a kind of sediment discharge facility called "sediment discharge channel" was developed by adding narrow slit and suspended plate to the curve device.The facility can effectively remove the coarse-grained sediment in the diversion channel and has a wide application prospect.In this paper,model tests are used to study the effects of narrow slits and suspension plates on water and sediment movement in curved channels,and to analyze the influence of different structural forms on the sedimentation effect of sedimentation channels.The main research contents and related conclusions are as follows:(1)According to the sediment deposition at the bottom of the channel after the model test,it can be found that the sedimentation in the inlet section is serious,while the curved section and the outlet section have only a small amount of sedimentation,which indicates that the sediment discharge channel can reduce the amount of sediment in the flow in the curve section and the concentration of sediment in the curve section and downstream flow.(2)Through the physical model tests,the influence of the height of the suspended plate,the magnitude of the flow,the water level,and the particle size of the sediment on the effect of sediment removal are studied successively.The experimental results show that:increasing the flow or adding suspension plates in this experiment can effectively optimize the device's sand removal effect;The effect of water level on improving the drainage efficiency of the sediment discharge channel is deeply affected by the factors of flow and the height of the suspension plate;In this experiment,when the range of sediment particle size is reduced,the rate of sediment discharge is significantly reduced.Therefore,fine-grained sediment is not easily discharged from the channel in this experimental device.(3)We optimize the structure of the sediment discharge channel by adding a swirling pool downstream of the sand conveying corridor.The experimental results show that the water consumption rate is reduced from about 32%to about 6%.The swirling pool has obvious optimization effect on the experimental device,and can play the role of secondary concentration and treatment of the sandy water flow coming out of the narrow slit.(4)Through the test of particle size distribution,the results show that 80%of the sediment with the particle size less than 0.08mm and 99%of the sediment with the particle size less than 1.0mm in the sediment flow which are treated by the sediment discharge channel.Figure 27 table 10 reference 92...