| Our country is a nation with rich water conservancy resources and it provides a reliable guarantee for the rapid development of water resources and hydropower construction. Some rivers carry large amounts of sediment, especially, for the middle and lower reaches of the Yellow River, the sediment concentration can reach hundreds of kilograms per cubic meter. Sometimes it is even higher that it becomes high-sandiness flow. About the hydraulic characteristics of water, many scholars conducted a lot of research and obtained some research results. For high-sandiness flow, most of research is the characteristics of fluctuating pressures that are different positions along the depth of the flow section of river which conveys sediment. In the high dam discharge engineering, hydrostatic pressure, average pressure and fluctuating pressure of cushion basin are the practical problems in engineering.In this paper, high-sandiness flow is regarded as the research object, a model is used to analyze the hydrostatic pressure. In addition, the average pressure and fluctuating pressure of cushion basin are analyzed by the table hole model test of one engineering project with the scale of 1:100. The main research results and conclusions are as follow:(1)Base on the independent design test apparatus, hydrostatic pressures of different sediment concentration flows are measured. It is concluded that hydrostatic pressure of sediment-laden water is nonlinear along the depth of water. The sediment concentration is higher and the depth of water is more shallow, the hydrostatic pressure coefficient of high-sandiness water is smaller. Compared with the clean water, the minimum value that is 0.8671 reduced by 13.29%.(2)The average pressures of cushion basin become higher as the increase of sediment concentration. Under different water conditions, the shock pressure trends along with the increase of sediment concentration are different. When the water flow condition is strong, the shock pressure along with the increase of the sediment concentration shows a trend of linear growth. When the water flow condition is weak, the shock pressure along with the increase of the sediment concentration shows a trend of decrease after the first increase. The maximum value of sediment-laden water is 3.17 times of water.(3)The characteristics of fluctuating pressure in cushion basin are analyzed. Under different water conditions, the characteristics of fluctuating pressure along with the increase of sediment concentration are different. When the water flow condition is strong, the fluctuating pressure along with the increase of the sediment concentration shows a trend of increase after the first decrease. Compared with the water, the maximum value decrease 51.92%.When the water flow condition is weak, the fluctuating pressure along with the increase of the sediment concentration shows a trend of decrease after the first increase. Compared with the water, the maximum value increase 78.82%. |
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