RESEARCH ON CREATING BLASTHOLE IN ROCK OR CONCRETE BY CYLINDRICAL SHAPED CHARGE WITH METAL CONICAL BOTTOM

Abstract

Destroying rock or concrete by explosive charges inside the borehole is much more effective than the charges outside the obstacles. Therefore, the study on methods of creating blastholes with the shaped charge is very significant in practice. Based on the theoretical analysis on the process of forming the piercing flow of the cylinedercad shaped charge with a metal lined funnel and explosive hydrodynamic theory, in the paper is established the method of calculating the parameters of depth and diameter of piercing holes formed in obstructions when exploding the shaped charges. Combining the design, producing of a the cylindrical shaped charge model with a steel lined funnel and conducting experiments to creates piercing holes in the B22.5 concrete block. The results are the size parameters of the piercing holes and value of specific energy for destroying concrete B22.5 under the piercing flow due to explosion. This result will be applied to calculate the piercing hole parameters when blasting in concrete or rock through the similitude effect of explosion method, in case of designing, using the shaped charge which is similary disegned in experimental models.