Study Of Fractured Rock Under Different Impact Load And Energy Dissipation

Ore-bearing rock material under dynamic load under the action of dynamic mechanics performance characteristics and the impact crushing energy evolution process is very complex. This article through the Hopkinson impact under the condition of uniaxial loading experiment, get the granite specimen, mix rock specimens and magnetite specimen fracture energy for three kinds of rock specimens die law theory data, theory research and guide the engineering practice for laboratory provides a solid foundation to support data. At the same time, the laboratory experimental study of rock crushing energy, respectively for Qi Da Shan magnetite iron ore granite area, migmatite area and area of actual engineering blasting test, collect the ore-bearing rock blasting broken characteristics, effect, analysis of energy consumption of the broken rules similar to the laboratory. Will now in this article, through experiment and theoretical analysis the conclusion summed up as follows:Based on the experiment found that rock sample dynamic stress and strain change rule similar to static experiment results.By analyzing the damage processing which rock damage from the initial cash before excessive impact load to the elastic-plastic deformation until damage at the end.The dynamic fractue progress of rock was revealed, Popular speaking, when the rock specimens under impact load, its own space, squeezed microcracks which was forced to reduce the relative space, dislocation and even new defects. In addition, the impact test found that the dynamic compressive fracture strength of the rock size increase with the increase of impact loading speed. At the same time, under the same impact velocity, the compressive fracture strength of three kinds of rock specimens show the largest granite and magnetite and the characteristics of mixed rock the smallest. Three rock specimens of the average strain rate increases with the increase of impact loading speed, and at the same impact load under the action of magnetite average strain rate of maximum performance, granite average strain rate and average strain rate of migmatite times the smallest dynamic mechanical characteristics.Can be found by Hopkinson impact test the impact of the warhead, the incident energy and the effective of the rock broken into increasing function relationship between energy consumption and the effective crushing energy consumption increases along with the impact of the incident energy. Specifically, the specimen is impacted by the same incident energy, granite specimen can effectively break increases with the increase of the incident wave energy, the largest magnetite specimen can effectively break times and migmatite magnetite can effectively break the smallest rule of the specimens. This rule to reflect the energy utilization of rock specimen, from the perspectives of specimen itself, the granite and magnetite structure relatively dense mixed rock specimen, the crack defects such as weaker, therefore, in the same incident can hit the deformation of the defect in the used in energy consumption is relatively less, and the corresponding effective energy consumption value is big. From a macro point of view, three degrees of rock specimen broken block and incident reduction function relationship between energy consumption and the incident energy is smaller, the greater the specimen broken blocks of and in the same incident can impact, the largest mixed rock specimen blocks of the characteristics of The Times and magnetite, granite blocks of the minimum. From the microcosmic point of view, rock specimens of unit volume per unit time through energy consumption value is bigger, the incident energy consumption under the same energy density values.Laboratory got broken energy consumption patterns in a certain ratio column amplifier, transplanted Qi Da Shan iron ore on-site test, by adjusting the specific charge for different energy consumption to release a quantity. A large collection of analysis shows that the broken blocks of the broken pieces of the rock and the relationship between the explosive energy consumption with lab about the same. The average degree of size of sample after crushing decreases continuously with the increase of specific charge, between the linear decline significantly. This feature seemingly and laboratory with nonlinear relationship is different, because of the high laboratory test sensitivity, it can show the experimental effect parameters and the experimental results. Their essence is the same, the blocks are broken decreases with the increase of the energy consumption of broken. So can impact energy dissipation through laboratory experiments, grasps the rock breaking the law of energy dissipation, to instruct the effective utilization of blasting energy and broken ore mining to improve mine economic benefit is significant.