基于SPH露天台阶爆破优化研究

针对露天深孔台阶爆破容易出现块度不均匀、大块率高等问题,运用经验公式法对台阶爆破参数进行计算并确定爆破方案,建立基于光滑粒子流体动力学(SPH)的台阶数值模型,对深孔台阶爆破孔排距共同作用下的岩体损伤情况及孔间应力大小进行研究。研究结果表明:孔排距会影响炮孔间的应力叠加作用,模拟过程中SPH粒子能良好地模拟出爆破过程中岩石运动状态和岩石损伤范围,当孔间距为8.5m、排间距为5.0m,爆破效果最佳。将模拟结果应用于现场试验,大块率较优化前降低了10.3%,块度平均合格率提高了5.2%,现场试验与模拟结果最优爆破方案效果高度一致,说明利用SPH的数值模拟方法研究台阶爆破是合理可行的。研究结果可为相关台阶爆破孔排距选择提供依据和参考。

Optimization study of open pit step blasting based on SPH

Aiming at the problems of uneven block size and high block rate in open-pit deep hole bench blasting, the empirical formula method is used to calculate the bench blasting parameters and determine the blasting scheme. The bench numerical model based on smooth particle hydrodynamics ( SPH ) is established to study the rock mass damage and the stress between holes under the joint action of hole row spacing in deep hole bench blasting. The results show that the hole row spacing will affect the stress superposition between the blast holes. In the simulation process, SPH particles can well simulate the rock movement state and rock damage range during the blasting process. When the hole spacing is 8.5 m and the row spacing is 5.0 m, the blasting effect is the best. The simulation results are applied to the field test. The large block rate is reduced by 10.3 % compared with that before optimization, and the average qualified rate of block is increased by 5.2 %. The field test and the simulation results are highly consistent with the optimal blasting scheme, indicating that it is reasonable and feasible to use SPH numerical simulation method to study bench blasting. The research results can provide basis and reference for the selection of row spacing of related bench blasting holes.