Application of slotting-pipe shaped blasting for hard-rock rapid driving

摘要

The cumulative blasting using PVC slotting pipe was tested for rapid driving in hard-rock roadway construction.First,the outhors optimized blasting parameters on 2.2 m scheme,and did both-sides comparative experiment of the surrounding holes after the blasting success.The results show that the application of slotting tube obtains four more cut contours than the case without it.Finally we did full-section control and non-control blasting comparative experiment,the results show that the rates of half-hole marks and the non-smooth grades of the cut contours can reach 95％,hole spacing is expanded to larger than 550 mm,and 550 mm is the best under the K2 limestone conditions.