岩石钻孔爆破粉碎区计算模型的改进

为了研究炮孔周围岩石的破坏机理，准确预测粉碎区的范围，提出了一种计算钻孔爆破粉碎区范围的改进模型。该四分区模型考虑了破裂区内侧的环向压应力和炮孔空腔膨胀的影响，假定粉碎区为丧失了内聚力但仍具有内摩擦力的散体介质。采用弹塑性力学理论推导了柱状装药起爆条件下的岩石钻孔爆破粉碎区半径公式。计算结果表明，岩石钻孔爆破粉碎区范围通常为1.2~5.0倍炮孔半径，不同种类岩石的粉碎区范围差别很大。与其他计算模型相比，本模型的计算结果与实验数据更吻合。

Improved calculation model for the size of crushed zone around blasthole

To explore the breakage mechanism of rocks around the blasthole and to accurately predict the size of the crushed zone in drilling and blasting, an improved calculation model for calculation the size of the crushed zone was presented. The four-region model was established with hoop compressive stress in the inner part of fractured zone and cavity expansion effect taken into account. The material in the crushed zone is assumed to be granular medium without cohesion but with internal friction. On this basis, the formula for the crushed zone radius in drilling blasting is derived by elastic-plastic mechanics theory. The analysis shows that the size of the crushed zone ranges from 1.2 to 5.0 times of the blasthole radius, and there are notable discrepancies among rock types. Compared with other models, the improved model is in better agreement with the experiment data.