崩落法采场中深孔拉槽爆破对相邻充填法采场稳定性影响研究

某镍矿1595m水平8行以东拟定采用崩落法采矿,8行以西的1610m水平以及整个1474m水平采用充填法采矿。崩落法采场首次中深孔拉槽爆破药量为2300kg,约为充填采场进路正常回采浅孔爆破药量的50倍,为分析首次中深孔拉槽爆破对1610m及1474m水平充填采场稳定性的影响,采用钻孔压力监测、巷道变形收敛监测、爆破振动监测等手段对充填采场的稳定性进行了监测与研究。分析监测数据可知:崩落法采场拉槽爆破后,与其相邻的2个充填采场钻孔压力计监测的压力值未发生显著变化,采场进路也未发生明显变形收敛;爆破振动监测仪在充填采场监测到的最大爆破振动速度均小于充填采场自身浅孔爆破监测值和相关的安全允许值。监测结果表明,1595m水平崩落法采场中深孔拉槽爆破未对其周边相邻充填采场的稳定性产生不利影响,充填采场可继续进行正常采矿作业。本研究可为该镍矿充填采场的稳定性评估提供依据,同时也可为类似矿山提供参考依据。

Influence of medium-deep hole slot blasting on stope stability of adjacent filling stope

Caving method was adopted to mine for the east of horizontal line 8 of 1595m in a nickel mine, while filling method was adopted to mine for the west of horizontal line 8 at the level of 1610m and the whole level of 1474m. In the caving stope, the explosive amount of the first medium-deep hole draw-trough blasting in the stope was 2300kg, which was about 50 times of the explosive amount of the normal shallow hole blasting in the filling stope approach. The stability of filling stope was monitored and studied by means of borehole pressure monitoring, tunnel deformation convergence monitoring and blasting vibration monitoring. Analysis of monitoring data indicated that after the chute blasting in the stope with caving method, the pressure value of the borehole pressure gauge in the two adjacent filling stopeshad not changed significantly, nor had obvious deformation convergence occurred in the stope approach. The maximum blasting vibration velocity detected by blasting vibration monitor in filling stope was less than the monitoring value of shallow hole blasting in filling stope and the relevant safety allowable value. The monitoring results indicated that the medium-deep hole blasting presented no adverse effect on the stability of adjacent stopes. The research can provide basis for the evaluation of stope stability of this nickel mine and reference for similar mines.