Purpose. To establish the analytical regularity of the calculation of the maximum value of the line of least resistance (LLR) of the explosive (E), taking into account the physical and mechanical properties of the rock mass and the detonation characteristics of the explosive. The methodology of research. Numerical modeling by the finite element method (FEM) to change the stress-strain state of the model established the value of the LLR at different diameters of the charge cavity, the pressure of explosion products and the tensile strength of rocks. Regression analysis obtained an empirical pattern of changes in the LLR depending on the physical and mechanical properties of the rock mass and the detonation characteristics of explosives. Mathematical modeling establishes analytical regularities of LLR calculation for zones of crack formation and intensive fragmentation. Findings. According to the change in the stress state of the model material around the charging cavity, the empirical regularity of changing the maximum value of the LLR depending on the diameter of the charging cavity and the diameter of the explosive charge, the density and rate of detonation of explosives, the compressive and shear strength. According to the developed calculation scheme, analytical regularities of LLR calculation for zones of crack formation and intensive fragmentation are obtained. By comparing the results of LLR calculation according to the obtained regularities, the most correct formula for LLR calculation was chosen, which turned out to be the analytical regularity of LLR calculation for the zone of intensive fragmentation. The originality. The power law is established for determining the LLR of an E, which comprehensively takes into account the radius of the crush zone, the diameter of the charging cavity and charge, the density and detonation velocity of E, the compressive strength of rocks, their fracturing and compaction under the action of rock pressure, which makes it possible to calculate the parameters of drilling and blasting (D&B) for breaking massif along the zone of intensive fragmentation. Practical implications. According to the results of the research, an analytical regularity of the calculation of the LLR of the explosive charge in the zone of intensive fragmentation was obtained, the use of which will allow to rationalize the D&B parameters in ore mining with the help of industrial explosives.
Purpose. Improvement of the current methodology for calculating the parameters of drilling and blasting (D&B) by determining the explosive force by the degree of realization of the detonation velocity for all types of industrial explosives (IE). The methodology of research. To solve the problem, a systematic approach was used, including an analysis of the current industry methodology for calculating the parameters of D&B in underground ore mining using IE, improvement of the power-law dependence of the calculation of the line of least resistance (LLR) of charges by determining the coefficient of explosive force of the IE, taking into account the degree of implementation of the burning rate, as well as approbation of the improved technique in the conditions of the operating iron ore mine. Findings. According to the methodology for determining the coefficient of explosive force of explosives (EX) according to the degree of implementation of the burning rate and according to the results of experimental studies of the change in the burning rate of the bulk emulsion explosive (EE) Ukrainit-PP-2, an improvement is proposed for the current industry methodology for calculating the parameters of D&B for the mines of the Kriviy Rig basin and the Private Joint Stock Society "Zaporozhye iron ore plant" (PJSS "ZIOP"). This made it possible, in the conditions of the experimental block of the mine "Yubileinaya" of the PJSS "Sukhaya Balka", using the bulk EE Ukrainit-PP-2, to increase the LLR and the distance between the borehole bottom up to 17%, and to obtain good results of ore reduction. The originality. The well-known power-law dependence of the determination of the LLR of borehole for rock breaking has been improved through the refinement of the coefficient of explosive force of the IE, which takes into account the degree of realization of the burning rate EX. Practical implications. The results of the research have improved the power-law dependence of the calculation of the LLR on the explosive force, taking into account the degree of implementation of the burning rate, the use of which will allow rationalizing the parameters of the D&B when breaking the ore mass using all types of IE.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.