轴向单缝偏心药柱爆破效应模型试验研究

为了探究轴向单缝偏心药柱在掏槽爆破中爆炸应力波传播规律和裂纹扩展情况，采用水泥砂浆模型试块开展模型爆破试验，采用超动态应变测试系统对爆炸应力场进行测量。结果表明:在相同爆心距下，背对切缝侧A测点仅为正对切缝侧B测点峰值应力的73.82%；一定角度范围内，峰值应力随偏转角度的增大而减小，偏转角度为0°时峰值应力最大，偏转角度为60°处峰值应力是偏转角度为30°处的74.39%，峰值应力在0°到60°范围内最大衰减达到32.74%；正对切缝方向产生一条贯通炮孔的主裂纹，裂纹发育优于其他方向，且切缝方向没有明显的细小裂纹，这表明轴向单缝偏心药柱具有良好的定向断裂能力。

Model test study on blasting effect of axial single-slit eccentric charge

In order to study the propagation laws of explosion stress wave and the crack propagation of the axial single-slit eccentric charge in the cut blasting,a cement mortar model test block was used to carry out the model blasting test,and the blasting stress field was measured by the super-dynamic strain testing system.The results showed that under the same explosive center distance,the peak stress at the measuring point A with its back to the slit side was only 73.82% of that at the measuring point B facing the slit side.In a certain range of deflection angle,the peak stress decreased with the increase of deflection angle.The peak stress was the largest when the deflection angle was 0°.The peak stress with the deflection angle of 60°was 74.39% of that with the deflection angle of 30°.The maximum attenuation of peak stress was 32.74% from 0°to 60°.A main crack penetrating the blast hole generated in the direction of facing the slit,and the crack development was obviously superior to other directions.At the same time,there were no other obvious small cracks in the direction of slit,which indicated that the axial single-slit eccentric charge had good directional fracture ability.