Experimental Study On Dam - Break Mode Of Tailings Deposited By Rainfall

The tailings dam is not only an essential structure for the normal production of mines, but also a potential hazard of mine safety. In recent years, with the rapid development of the mine industry, the number and scale of the tailings reservoir is increasing and the dam break accident of tailings dam is also increasing. Tailings dam break not only caused the loss of tailings, the more important is to give the downstream ecological and people’s lives and property caused great losses. Overall, there are many factors that affect the safety of the tailings dam. and the water is the key to the stability of the tailings dam. Therefore, this paper is to study the dam break induced by rainfall, analysis of the causes and process of dam break, revealing the formation mechanism of the tailings dam break that under different rainfall conditions. The research results can not only improve the safety and management level, reduce the adverse factors of the operation of the tailings, but also it can provide a certain reference for the tailings reservoir flood control.This paper is based on the laboratory soil test of tailings, study on the tailings dam break experiment under the rainfall. This paper mainly carried out the research work in the following areas:(1)Make the tailings laboratory convention soil mechanics tests, determination the tailings particle size composition、compressibility、permeability and shear strength a series of tailings parameters. Thereby to provide parameters for numerical simulation.(2)Finished under different rainfall conditions that induced tailings dam break test. Test results show:Full and local rainfall tailings dam overtopping before the defeat. the saturation line height rise with increasing water level of library. In the course of dam break two kind of rainfall patterns all appear dam silt stream flow increased rapidly in a short time and form "head cut erosion", the breach broaden the width and depth over time., the dam settlement obvious. The two different rainfall pattern is that during the local rainfall before break, tailing dam appears sand and water seepage, the dam settlement less than general rainfall dam settlement. Dam have the trend of moved to the downstream. Dam slope gradient decreases obviously. The test of library local rainfall infiltration dam break, due to the long time of the dam seepage, Dam slope gradually settlement that is below the water level library. Early breach shallow and wide, the depth gradually deepened over time, sediment flow small, the process of dam break is slower than overtopping dam break, the displacement of the dam body is small.(3)On the basis of the indoor accumulation dam and the laboratory soil test, using the Side software to analyze the dam model indoor for different rainfall intensity conditions that the infiltration lines and stability, the results show:the greater the rainfall intensity, the higher the saturation line, and the safety factor is reduced until the tailings dam break.In this paper, the use of indoor model test and numerical simulation combined method, analysis and summary of the rainfall induced tailings dam break, the research results provide theoretical basis for the prevention and reduction of the tailings dam.