Abstract: This study describes the complex approach to study the formation process of the cumulative jet and the depth of its implementation into marble and granite in case of rock directional shattering by means of cumulative column charges. As a source of directional explosion we used a cumulative column charge in metal coating. In accordance with the values of measured depths after implementing the cumulative jet into rock plates we got numerical values of initial cavity scale depending on the focal distance for different charge types. We describe a model experiment aimed at the study of cumulative jet implementation mechanism and creation of stress concentrator (of the initial cavity). There is an X-ray picture here to show the process of implementing cumulative jet into a rock plate and there are results of lab experiments to study the depth of jet implementation at different focal distances. We show the scheme of interaction of separate cumulative jet fragments with the rock. It was revealed how the mass velocities in reflected shock wave for a jet rear side depend on the jet front side velocity for marble and granite. The connection of the implementation depth of the cumulative jet with the distance to the mass became clear.
Kaerbek Rafkatovich Argimbaev and Isheysky Valentin Alexandrovich, 2016. Measuring the Optimal Focal Distance to Make Initial Cavity in the Mass of Solid Natural Resources. Research Journal of Applied Sciences, 11: 240-244.