Rock Fragmentation Patterns in Tunnels with Interbedded Surrounding Rock by Blasting with Slotted Blastholes
According to the relative position between interbedded surrounding rock and the peripheral holes,the relationship between bedding planes and the connecting line of the adjacent blastholes was classified into three kinds.Mechanism for bedding planes bringing impact to crack propagation in rocks between blastholes by blasting under typical work conditions(with bedding planes on the perpendicular bisector of the connecting line of blastholes)was explored by the LS-DYNA numerical simulation;and the effect of bedding planes in a different relative position to the connecting line of blastholes on the blasting effect of surrounding rock was also studied.It is found that the propagation speed of blasting vibration waves in sandstone is slightly higher than that in sandy mudstone.Under blasting loads,the surrounding rock above both softer layer and the beddings suffer severe damage.The superposition of two-blasthole blasting vibration wave peaks intensifies the damage to the surrounding rock.The blasting effect is poor when the bedding plane penetrates the blastholes,but the blasting effect is ideal if the bedding plane is on the perpendicular bisector of the connecting line of blastholes.
tunnel blastinginterbedded surrounding rockblasting with slotted blastholecrack propagationbedding planeperipheral holeblasting vibrationsurrounding rock damage
万方数据
维普
