Study on the Influence Mechanism of Large Diameter Empty Hole on Cutting Blasting Effect
Aiming at the problems of low utilization rate of blast hole,low footage of single cycle,low half hole rate,serious overbreak and underbreak and uneven contour surface in roadway excavation blasting of Dahongshan Copper Mine,four kinds of cut blasting models of three,four,five and six large diameter empty holes were constructed by numerical simulation software LS-DYNA.The numerical simulation study on the cavity forming effect of cut blasting under the condition of four large diameter empty holes was carried out,which provided guidance for the subsequent design of cut hole layout.The results show that the large diameter empty hole has a guiding effect on the blasting damage of rock mass.The area of blasting cavity induced by six large diameter empty holes is the largest,about 0.132 1 m2,which is 8.55％higher than that of five large diameter empty holes,2％higher than that of four large diameter empty holes,and 8.01％higher than that of three large diameter empty holes.The barrier effect of large diameter empty holes is obvious.The existence of empty holes can reduce the peak value of blasting vibration by 51.63％and the peak value of effective stress by 67.24％.
万方数据
维普
