Research On Movement Process Of Flow Sediment Due To Dam And Levee Failure

Most natural rivers are winding with plane forms, resulting in extremely complex river water flow movement. Compared to straight channel rivers, the potential of water flow erosion and sediment transportation is strengthened in the bending regions of natural rivers. In such a strong-power process especially the dam-breaking process, the high velocity of water flow, the fierce variation of water level, and the high capacity of carrying sand might cause sudden blunt, flash river silt, and strong erosion on the river bank. Furthermore, the influence of natural channel bending has a significant effect on sediment transportation. However, most of the existing models associated with dam-breaking process are hard to simulate and evaluate the real consequences of water erosion on the river bank and capability of river sediment transportation. The study on the influence of river bending, therefore, will be really meaningful on the water flow, the sediment transportation, and the characteristics of the transportation in dam-breaking process.The main objectives of this paper are:(1) To deduce curvilinear coordinate system of suspended sediment motion equation, the sediment motion equation and goes on bed deformation equation, by combining with the spread characteristics of the dam-breaking wave.(2) To establish and compare the fixed bed model, with different conditions of the moving bed model, set up more reasonably moving bed model, using the sediment transport motion equation under the waves and constant water flow.(3) To analyze the wave propagation and sediment movement of natural rivers under different bending degree in the dam-breaking progress, though the numerical simulation of river bend to wave propagation speed, the water form, and the bed deformation.(4) To establish a two dimensional river bend moving bed model in dam-breaking progress.