Influence of blast hole spacing on penetrating crack propagation of eccentric uncoupled charge
In order to study the influence of hole spacing of eccentric uncoupled charge on the penetrating crack propagation in smooth blasting,this paper first deduced the calculation method for hole spacing of eccentric uncoupled charge by using the formula of hole wall pressure of concentric uncoupled charge and the superposition principle of stress wave.Then,based on the obtained range of hole spacing,the propagation positions of penetrating cracks in three kinds of rock under different hole spacings were calculated.Finally,sandstone material was selected for numerical simulation.The results show that the penetrating crack is distributed on the eccentric side in eccentric uncoupled charge blasting and that the rock with high tensile strength has a large degree of deviation from the hole connection center line.When the hole spacing of sandstone is 60 cm,the propagation direction of penetrating crack coincides with the center line of the hole,and concentrated penetrating crack area appears below the center line.The increase of the hole spacing causes the penetrating crack to move away from the center line,resulting in under-excavation.After the eccentric decoupled charge blasting,the damage of rock on the eccentric side is obviously greater than that on the non-eccentric side.
smooth blastingeccentric uncoupled chargeblast hole spacingpenetrating crackhole connection center line
万方数据
维普
