SPATIO-TEMPORAL PARAMETERS OF THE FRONT OF THE FORCE FIELD IN THE SYSTEM OF ELONGATED CHARGES

Purpose and task is to study the nature of the formation of the force field in the heel region by the interaction of the upper end parts of adjacent charges.Research results. Based on the fact that outside the zone of plastic deformations the force field is created by stresses close to elastic, analytical studies used a simplified computing apparatus based on known data on the shape and numerical values of force and time parameters of a single pulse from a single cylindrical charge of a given mass and length. The main results. The regularities of the formation of the force field in the boundary zones of action of the system of adjacent elongated charges are considered. The phenomenon of field degradation observed near the end part of the charges, which has a negative effect on the overall mechanical effect of the mass explosion, is analyzed.Conclusions and practical consequences. The shape of the total field of maximum stresses on the middle axis between adjacent charges initiated simultaneously from the lower end should have manifestations of the cumulative effect in the area of the upper end areas of adjacent charges.Therefore, after the inclined counter power fronts, counter mass shifts should take place, generally directed towards the superbore layer of the rock mass at the level of the stamping. The technique of forming upward movements in the intercharging volume of the rock is a new technological element that takes over the experience of conducting mass blasting operations according to an effective traditional system of switching a network of wells in the form of a horizontal wedge or trapezoidal cut. Such a traditional scheme initiates successive pairwise counter mass shifts with short decelerations in the direction of the lateral slope of the ledge. In contrast to this scheme, the new technology of mass explosion is based on a combined technique of simultaneous lower charge initiation in groups of 2-3 rows and the use of traditional short decelerations between groups to prevent excessive seismic effect. Thus, in groups the combined scheme of KSP "vertical wedge" which promotes additional destruction of the top layer of the planted rock block and reduction of an exit ofoversized fraction at the level of a stamping is realized.Keywords: charges, cumulative effect, rock mass, intercharging volume, explosion, seismic effect, vertical wedge.