Copper Pit Mine In The Deep-hole Blasting Vibration Under The Pillar Stability Study

The study on the stability of ore pillar, which acts as a supporting structure for the mining system and recyclable material, is being paid more and more attention to. One of the main factors that influence the ore pillar's stability is blast vibration. Strong blast vibration is likely to cause the ore pillar rockmass to formate concentrated stress, bringing the security menace for the recovery of ore pillar and finally resulting in instability and convulsion. So it has profound theory and realistic meaning for the recovery of mineral resource and safety production of mines to study the effect of blasting vibration on the stability of ore pillar.Combined with the production practice of a Tong Keng Mine, the paper studies on the effect of underground middle-deep-hole blast vibration on the stability of ore pillar by blasting vibration monitoring, numerical simulation and dynamic stress evaluation. The main achievements of this paper are as follows:According to the mechanisms of the blasting seismic wave propagation,through monitoring underground deep-hole blasting on the spot and using linear regression to analyze the monitor data, it is obtained that the peak velocity attenuation rule of blasting vibration of Tong Keng Mine, which provides directions and references for the middle-depth-hole blast design.Based on analyzing and discussing the problem of determing the physical mechanical model, choosing the model parameters, inputting blast load and damping setting, according to the theory of response spectrum and the monitoring data on the blasting spot, the paper studies on the dynamic response rule of ore pillar under blasting load on the basis of using ANSYS finite element software for numerical simulation, and determines the explosive dosage to prevent the ore pillar from destroying.Through engineering-geological and ore pillar's rockmass quality investigation, the evaluation criterion of dynamic stress ratio, safety assessment for rock damage by blasting has been done in the paper. Furthermore, the paper also offeres the blast vibration peak value and the limiting value of maximum explosive dosage in middle-deep-hole blasting damage. And the results of numerical simulation and dynamic-stress-ratio evaluation are analyzed and compared.In addition testing on the optimization of blast parameters, the paper derives the optimal consumption of explosives and millisecond intervals, and puts forward the measures to reduce blast vibration in the mine.