Study On The Influence Of Rainfall Factors On Tailings Dam Break And Its Safety Warning Technology

Tailings is the main control project and major hazard source of mine.Production practice shows that as the tailings dam body constitutes the loose characteristics of the media,resulting in external disturbances,such as rainfall,earthquake,liquefaction and other conditions easily lead to tailings dam accident,especially in the case of continuous rainfall can easily lead to tailings dam break.Therefore,it is necessary to carry out the research on the dam breaking mechanism and safety early warning technology of the tailings dam under the rainfall factor,which is important to improve the safe operation of the tailings dam under the rainfall conditions,to realize the prediction and forecasting of the dams of the tailings dam and to ensure the safety of the life and property of the downstream residents.This paper makes a detailed statistics on the rainfall situation of 14 tailings in Jiangxi Province since 1960.In this paper,the rainfall situation of tailings dam under rainfall condition is obtained.On the basis of dam example and according,physical simulation test and the numerical simulation test,the evolution rule of the tailings dam in the progressive dam and the instantaneous dam break and the flow characteristics of the flow water are analyzed.Then,the optimization experiment of tailings dam based on the acoustic signal of the wave guide is carried out.The acoustic characteristics of the different wave guide rod and the gravel and the acoustic characteristics of the dam Prediction Method of Dam Damage in Mine Dam are analyzed.On the basis of this,the dispersion equation of the elastic wave in the wave guide rod is established and the attenuation curve is calculated.Moreover,the attenuation law of the elastic wave propagating in the wave guide rod is analyzed.Then the wave rod diameter and the gravel particle size are optimized.Finally,a series of monitors were done in terms of vertical,horizontal directions and elastic waves for the tailings dam while the capabilities of the tailings dam is analyzed scientifically.The main research content based on a tailings reservoir include:(1)By analyzing the rainfall characteristics of 6 failure cases of tailings pits in Jiangxi Province,it is concluded that both the progressive dams and the instantaneous dam failures occur during the flood season.In the month of the accident,the tailings reservoirs have 3-day continuous rainfall.And on the day of cause instantaneous dam broken,there is 50mm precipitation of heavy rain.(2)The damage level of the break in the tailings dam highly depends on the invasion induced by overflow washing.In the case of progressive dam-break,the dam-break process shows a steep-type progressive failure mode.Under the instantaneous dam-break condition,the bottom slope of the dam body is opposite to the direction of the dam-break flow.Silt and fold water flow under the action of the formation of dam downstream counter-clockwise swirl;the left side of the dam section of the formation of left and right swirling flow.(3)The elastic fractal dimension of the elastic wave is increasing and then decreasing rapidly.The elastic wave frequency is located at 15kHz～77.8 kHz,which can be used as a precursor to the dam.(4)The attenuation of the elastic wave in the wave guide rod decreases with the increase of the diameter of the wave guide rod.When the wave guide is wrapped with 10-16mm particle size,the frequency of the elastic wave is in the range of 0～0.25MHz in the largest number of occurrences.Therefore,in engineering practice,the large diameter of the wave guide rod and 10-16mm particle size gravel combination should be used.(5)The logistic regression model is established according to the statistical analysis and the data of rainfall which is accumulated before the accidents of tailings dam.Additionally,quantity relationship between the precipitations of rainfall in a specific day and precipitations in a period is achieved.Since the safety level of the tailings dam is uncertain,the horizontal,vertical and the elastic waves are monitored.According to the monitoring results,the tailings dam is stable in general.