Results are presented on the effect of firing rate on pressure pulse in charge camera and fracture stress during spalling. Results are presented of comparative calculations using the equations of autocatalytic reactions of firing rates and escape of reaction products for the system of sodium chlorate - polythene (propylene) in pipe shape. Dependences are obtained of firing rate on concentration of gas generating mixture, its density, components size distribution and cartridge case size. Experimental and computational data were used to consider the conditions of firing turning into explosion for compositions based on sodium chlorate and hydrocarbons in layered and powdered systems. The relation is retrieved between the technological parameters of mining activities (blast hole to blast hole distance, blast hole diameter, depth of cartridge placement) and specific cartridge consumption along the spalling line with gas generators going off.
This article is devoted to application of the cumulative charges on the open-pit and underground minings. The analytical response of the crack length on the geometrical parameters of the charge, hole and of the properties of rocks is invented.
Elastic – plastic balance of the hills massif is examined under the Stavrogin's condition of destruction under symmetric boundary conditions in view of the heterogeneity of a file arising at artificial freezing of friable watery breeds with the help of freezing columns. Formulas for definition of pressure and movings to plastic and elastic areas are received. The border between elastic and plastic areas is found. The area of existence of the decision is determined.
This paper deals with issues related to mathematical modeling of optimization of stretched shaped charge parameters on the basis of similarity test. By means of the numerical method of random search the necessary rational parametric variables for designing rational designs of stretched shaped charges are obtained.
The elastic-plastic equilibrium of a rock massif is considered taking into account only the forbidden state. Formulas for determining stresses and displacements in the elastic and forbidden zones are obtained. The boundaries between the forbidden zone and the elastic zone are found.
The experience of drilling and blasting operations at limestone quarries in Finland is described. The comparative characterization of drilling and blasting parameters, adopted for similar conditions in Russia and Finland, is carried out. The problems inherent in explosive mining of construction materials in Russian quarries are defined. The directions for improving the parameters of drilling and blasting operations are outlined, which will improve the quality of blasting preparation.
In our country, for the last 10-15 years, a new type of explosives and charges made of them with the necessary complex of energy and gas release have been developed. At explosion of these charges, their throwing properties are implemented in full measure, i.e., brisant influence on a rock is practically excluded. The pilot and industrial production of these charges is mastered and they are successfully used in a number of block quarries in the Leningrad, Murmansk and Irkutsk Regions and in the Republic of Karelia and are permitted by the Russian State Mine Technical Supervision Service for permanent use in the mining industry. The explosion of these charges provides an explosive transformation in the form of explosive combustion in the explosive chamber (borehole, well), creates a pressure that is significantly lower the compressive strength of the rock and 1.2-1.5 times the breaking strength of the rock, increasing the exposure time on the walls of the explosive chamber gaseous products of explosion (PE). Employees of the rock destruction department of the St. Petersburg Mining Institute together with employees of the SKTB "Technolog" and NPO "Kristall" have developed special charge designs: elastic tubular charges (ZET "Granilen") and hose charges (ZShA).
Применение зарядов ВВ направленного действия для контурного взрывания и предварительного щелеобразования в массиве горных пород в последние годы привлекает внимание многих исследователей ...
