The Study On The Hydraulic Layout Of Sediment-flushing Structure In Front Of Dam

The silt sedimentation in Reservoir caused the effective capacity reduction, life expectancy reduction and the water and sediment balance destruction in lower reaches of river and other issues which have become a major management problem about reservoirs, rivers and hydro-power station. Especially in the Yellow River Basin, the large quantities of silt cause the reservoir serious constraints on the use. Therefore, research about the building of discharging the silt suitably in the main current hydro-junction project of Yellow River is important and practically significance.This paper presents a new type of arrangement of sediment-flushing structure: by installation the pipeline extending the reservoir area through the sand bottom outlet or other holes make the upstream erosion funnel extend by the way of sub-opening to the pipeline to increase the erosion of funnel to get the purpose of scouring. And this arrangement is analyzed through the means of hydraulic model test and numerical simulation. The main contents and results including the following:(1) The establishment of two-dimensional, three-dimensional numerical model of the scouring funnel before the simulated flushing pipes calculated the scope and impact factors of the scour funnel under different hydraulic conditions and the relationship between the scouring scope and flow, water level.(2) The new layout of sediment-flushing structure is studied by model test. By analyzing of the experimental data, we can get the pipeline's load when running, as well as the erosion of the funnel. Besides the experimental data and numerical simulation results were compared, and which have a better consistency.(3) The layout of pipeline flushing of Xiaolangdi is also be simulated, and getting the funnel situation before the pipeline under different hydraulic conditions. The way of sediment building layout is initial developed, which is the discharging of silt reference to Xiaolangdi.