| Over these years, there are accidents frequently happened in a number of small andmedium sluices built in the eighties and ninety-century, mainly in energy dissipation structureof downstream of the sluices, especially in the ramp connecting section to the stilling basin.This paper takes the sluice whose floor was lifted in the ramp connecting section to thestilling basin for example, systematically analyze the force and draw the cause of the accident.The results show that in order to avoid this kind of instability accident in energy dissipationstructure of downstream of the sluices, this paper provide some suggestions for the sluicedesign and operation.Beside their own weight, the ramp connecting section and the floor to the stilling basindownstream of the sluices are under the pressure of the upward uplift and downward water.Only when we analyze exactly the uplift pressure and water pressure in the different situationwould it be figured out what kind of circumstances in which the pressure on the downstreamof the sluices causes most adverse impact.In order to calculate the uplift pressure more accurately, this paper uses the finite elementsoftware to simulate the seepage field of the downstream of the sluices. We can acknowledgethe osmotic pressure in different locations, which is helpful for calculate the uplift pressure.We compare the improved the drag coefficient method and the sluice uplift pressure, modelrationally, and calculate the accurate uplift pressure in different conditions.Calculation of hydraulic jump, especially slope water jump, is the difficulty of hydraulics.All kinds of formulas used now are the empirical formula which isn’t widelyacceptable. Thispaper uses the mainstream CFD software——FLOW-3D to do the simulation calculation inall types of conditions, and compares with the on-site water jump route. After optimize themodel, we get the relatively accurate calculations.After combining the results of uplift pressure and hydraulic jump, this paper comparesthe different situation of the brake energy dissipation structure under pressure in all types ofcondition, then obtains the most unfavorable conditions. Finally, we provide some advice on sluices design and operations. |
