Study On Overtopping Dam Failure Mechanism And Protection Measures Of Tailings Reservoir

Tailings reservoir is an important facility in mine production.With the continuous development of mining engineering,the characteristics of tailings reservoir such as large quantity,high potential energy and high risk are more obvious.In recent years,the frequent tailings dam failure accidents have caused huge casualties and property losses,and their safety and stability have attracted wide attention from society,enterprises and academia.Tailings reservoir is a dangerous source of artificial tailings sand flow.Once dam breaks,high potential tailings flow will affect the ecological environment and life and property of several kilometers downstream.There are many factors affecting the safety of tailings pond,among them,the collapse caused by flood overtopping is one of the main causes of tailings dam failure.Therefore,it is of great significance to study the mechanism of overtopping dam break for controlling the dam break process and predicting the dam break disaster.At the same time,the simulation study of dam-break tailings flow evolution process and protective measures is carried out to explore the protective effect of different protective measures,which can provide reference for disaster prevention.In this paper,mechanism analysis,physical model test and numerical simulation are used to systematically study the process mechanism of overtopping dam-break in tailings pond.The evolution mechanism of tailings flow in the flat downstream terrain is revealed.Finally,the comparison and selection of different types of protective measures are carried out.Specific work is as follows:(1)The failure mechanism of tailings dam is analyzed,and the ' scarp ' failure mode of dam failure is explored.From the perspective of mechanism analysis,combined with the process of overtopping dam failure of earth-rock dam and related experimental and theoretical research,the whole process of overtopping dam failure of tailing dam is studied in stages.The transport mechanism of tailings is analyzed,and the commonly used dam-break model and tailings flow model are discussed.(2)The calculation theory and calculation characteristics of CFD numerical simulation method are introduced,and the sediment erosion model and high concentration particle flow model commonly used in the study of tailings dam failure are pointed out.The calculation theory of each model and the calculation method of key parameters are explored to prepare for the subsequent numerical simulation.(3)The physical model test and numerical simulation study of overtopping dam break of tailings pond were carried out,and the influence of different particle sizes of tailing sand on the process of overtopping dam break of tailings pond were discussed.The two characteristics of surface scouring and under cutting erosion in the process of dam break were pointed out,which indicated the feasibility of numerical simulation method in the study of overtopping dam break..(4)The physical model test and particle flow numerical simulation model are used to analyze the evolution mechanism of dam-break sand flow in the flat open terrain downstream;The blocking and diversion protection mechanisms of different types of blocking dams are analyzed,and the protection effects are analyzed from the downstream impact range of dam-break sand flow and the siltation of tailings sand flow,which provides a reference for the dam-break protection of tailings pond engineering.