Study On Numerical Simulation Of Tailing Sand Advancing After Dam Collapse

Used for storage of metal or non-metal mine tailings, the tailings reservoir is also a potential dangerous source. Over the years, tailings dam failure events are occurring sometimes both at home and abroad, which have serious impact on the surrounding environment and the citizens living at downstream. The process of the tailing sand advancing after dam collapse is a very complex problem. The relative research about it is very lack, and it is still using the calculation method of reservoir dam to solve the problem of tailings dam. Therefore, it is necessary to strengthen the study of tailings dam-break.According to the existing research on the calculation methods of tailings sand advancing after dam collapse, it is still necessary to study the rheological characteristic of tailings slurry, flow control equations, numerical calculation method, parameter determination method and so on. In this paper, in order to analyze the theological characteristic of tailings slurry and determine its parameter values, three different kinds of tailings sand is used to compound as saturated slurry for the rheological tests. Taking a tailings reservoir calculation as an example, study on the numerical simulation of tailings sand advancing after dam collapse by using fluid dynamics analysis software ANSYS CFX. Then, through a variety of simulations, analyze the submerged area and depth of tailings slurry, which is effected by rheological characteristic of slurry, total quantity of the tailing sand collapsed, and channel slope at downstream. In the end, we try to set a detention dam in different location at the downstream, then discuss its impact to the advancing of tailings slurry. The research mainly received following understanding:(1) The rheological characteristic of tailings slurry is in accordance with the change of Bingham fluid, so the Bingham model can be used to simulate the tailings slurry. However, the rheological properties under different kinds of tailings slurry are very different, and concentration has a significant impact on the rheological properties for the same tailings slurry.(2) The empirical formula method, based on the reservoir dam, has little correlation to the tailing dam. It can’t consider the rheological properties of tailings slurry and the influence of terrain at downstream. So its applicability has yet to be studied and improved. However, numerical simulation method is different with the empirical formula method. It can not only consider the effect of terrain and slurry flow characteristics, but also simulate the dynamic process of slurry and confirm the region effected by slurry. With the appropriate calculation parameters, it can get reasonable results.(3) Slurry’s rheological characteristic, total collapse of tailing sand, and channel slope at downstream have remarkable effect on the advancing of tailings slurry. The smaller slurry rheological parameter is, the farther submerged distance becomes. While the larger total quantity of the tailing sand collapsed is, the farther submerged distance becomes. Also, the steeper channel slope leads to farther submerged distance. Besides, the blocking effect of detention dam on the evolution of tailing slurry is very obvious. The setting of detention dam can effectively reduce submerged area of tailing slurry.