| The common waste rock of the dumping in the mine and mineral discharge tailings in the concentrating mill belong to loose media accumulation deposit,and the slippage of these accumulation deposit will cause serious safety accidents,which will bring incalculable losses to the country and the society,so it is of great value and significance to predict the slippage of the dump and tailings.At present,the monitoring of the stability of the dump and tailings is mainly to monitor of the deformation and displacement of the surface and the inside,which cannot truly reflect interface slippage situation between the internal loose particles.The acoustic emission can reflect the damage mechanism of the internal monitored object,and the sliding friction of the loose media between the dump and the tailings will produce acoustic emission.Therefore,the acoustic emission is used to monitor the stability of the dump and tailings which has its possibility.In this paper,we study one of the dumplings of the loose media accumulation deposit,constructing the bulk slope model to carry out the acoustic emission test of the slippage damage of the bulk slope.Utilizing the combination of experimental study and theoretical analysis,we have carried out the study of the characteristics of acoustic emission signals during the process of the bulk slip dilapidation,and the following conclusions are obtained:Firstly,by designing a set of slanting model test device,we have constructed the slip surface which carries out the slippage damage of the bulk slope.At the same time,three acoustic emission signal monitoring points are arranged on the top of the slope,slope and slope bottom.The waveguide spreads the acoustic emission signal which is used to monitor the damage process of the bulk slope.The experimental results show that the slip damage of the bulk slope is a gradual and energy accumulation process,that is,before the large-scale destruction,there will occur several small-scale destruction,and the slope area can occur a waste rock rolling phenomenon in a large scale.This is an omen of large-scale slip destabilization.Secondly,combined with the size of the test process and the size of the damage scale,we divided the whole bulk slip damage process into several stages and analyzed the parameters of the acoustic emission signal in the whole process.The results showed that the acoustic emission activity of the bulk slope is along with the whole slippage damage process,the change of the acoustic emission characteristic parameters at each stage can reveal the evolution of the internal state of the bulk slope to a certain extent.Thirdly,there are significant differences in the acoustic emission characteristics at different positions,which is at the bottom of the 3 # points to receive the strongest acoustic emission signal,and the analysis of the three points is more reflective to the situation of the slippage damage.At the same time,according to the time of the sound emission signal at different positions,it is possible to predict the range of the occurrence of the damage.When all the monitoring points have the acoustic emission signals and the acoustic emission signals suddenly strengthen,it is indicated that there is the occurrence of large-scale slip damageFourthly,The change of the correlation dimension D and r of the slip damage process is closely related to the evolution of the internal state of the bulk,where the fractal dimension D will appear the maximum near the near slip phase and then suddenly the sudden drop phenomenon and will appear "cliff-type" phenomenon of accumulation near the slip damage to the r-value,which can be used as an omen to the damage of the bulk slope instability.Fifthly,using the wavelet packet band energy analysis method,we have emphatically focused the analysis of band energy distribution at the slippage destruction position of the slanting slope.When the dispersion slip is obtained,the main frequency of the acoustic emission is mainly located at 15.6 kHz ~ 77.1 kHz,corresponding the secondary frequency is mainly located at 77.1 k Hz to 140.6 kHz. |
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