某露天钨矿爆破振动对采区主溜井稳定性影响

The Influence of Blasting Vibration on Stability of Main Chute in an Open-pit Tungsten Mine

某钨矿主溜井服务年限已达16年,溜井整体稳定性降低,且目前存在溜井降段的需要,随着爆心距的减小,主溜井存在失稳风险。本文通过爆破振动监测、爆破信号分析对采场主溜井稳定性进行研究。分析结果表明:在现有最大单段药量低于150 kg、爆心距大于100 m的情况下,位于溜井附近的测点振动速度最大为2.54 cm/s,低于爆破振动安全标准;爆破振动主要能量集中在0 Hz~20 Hz,主要分布频带较窄,各测点信号的边际能量谱峰值所对应的频率在5 Hz~10 Hz,随着爆心距的增大,其边际能量幅值减小;拟合确定适合该矿山萨道夫斯基公式,同时爆破振动强度预测结果表明,在与溜井距离小于20 m时,建议单段最大起爆药量低于50 kg。

The service life of the main chute of a tungsten mine has reached 16 years,the overall stability of the chute is reduced,and there is a need for the down-section of the chute at present,and with the decrease of the explosion center distance,there is a risk of instability in the main chute.The stability of main chute in stope is studied through monitoring blasting vibration and analyzing blasting signal.The analysis results show that when the maximum charge weight per delay is less than 150kg and the explosion center distance is greater than 100m,the maximum vibration velocity of the measuring point located near the chute is 2.54 cm/s,which is lower than the blasting vibration safety standard;The main energy of blasting vibration is concentrated in 0 Hz~20 Hz,and the main distribution frequency band is narrow.The frequency corresponding to the peak value of marginal energy spectrum of each measuring point signal is 5 Hz~10 Hz,and the marginal energy amplitude decreases with the increase of the explosion center distance;The Sadovsky formula suitable for the mine is determined.Meanwhile,the prediction results of blasting vibration intensity show that when the distance from the chute is less than 20 m,the maximum charge weight per delay is recommended to be less than 50 kg.