The selection of efficient drilling and blasting technology to achieve the required particle size distribution of blasted rock mass and reduce ore dilution is directly related to the accurate definition of rock mass properties. The zoning of the rock massif by its hardness, drillability and blastability does not consider the variability of the geological structure of the block for blasting, resulting in an overestimated specific consumption of explosives. The decision of this task is particularly urgent for enterprises developing deposits with a high degree of variability of geological structure, for example, at alluvial deposits. Explosives overconsumption causes non-optimal granulometric composition of the blasted rock mass for the given conditions and mining technology. It is required to define physical and mechanical properties of rocks at deposits with complex geological structure at each block prepared for blasting. The correlation between the physical and mechanical properties of these rocks and drilling parameters should be used for calculation. The relation determined by the developed method was verified in industrial conditions, and the granulometric composition of the blasted rock mass was measured by an indirect method based on excavator productivity. The results demonstrated an increase in excavation productivity, thus indicating the accuracy of given approach to the task of identifying the rocks of the blasted block.
The problem to ensure the safety of objects which are in the area of blasting operations, ensuring the destruction of hard rocks, remains relevant. The article presents the results of a large-scale experiment to determine the safe conditions for conducting drilling and blasting operations near the active gas pipeline. The simplest and most reliable way to ensure the safety of the protected object from seismic impact is to reduce the intensity of the seismic wave, which is achieved by changing the parameters of drilling and blasting operations. This requires research to determine the impact of blasting operations on the parameters of seismic waves and the development of methods for measuring these parameters. The paper presents a detailed analysis of the seismic blast wave impact on the displacement of the ground and the model gas pipeline. The features of seismic monitoring during blasting operations near the active gas pipeline are shown. The seismic coefficients and attenuation coefficient of seismic waves are determined. It is proved that the readings of the seismic receivers on the surface and in the depth of the massive differ by two or more times.
Research carried out proves that blast seismic effect i.e. displacement velocity in a seismic wave and efficiency are the function of specific charge with rock mass contact surface. Dependence of blasting fragmentation coefficient from diameters and charge density variation is given.
The article considers the problem of size distribution of grain-size composition of the blasted rock mass, rock fragments blasted rock mass and rock blockiness. The logarithmic-normal distribution law is laid down for all blasted granite mass products. It was proved, that logarithmic variance of logarithmic normal distribution law of the fractured rock mass fragments’ distribution is a structural invariant on the level of statistical universe of the block and fragments.
Experimental studies of the granulometric composition of rock mass obtained as a result of blasting and impact destruction confirmed good convergence of experimental data with the theoretical log-normal distribution law. It is proved that the logarithmic dispersion of the lognormal law of distribution of pieces of the fragmented rock massif is a structural invariant at the level of the statistical set of blocks and pieces. The model of destruction of polymineral rocks by explosion energy is proposed.
The object of the research is the state of safety of buildings of engineering structures and the environment, located in the zone of influence of mining operations under the influence of seismic blasting and shock air waves from blasting operations. Full-scale measurements of parameters of seismic blasting and shock air waves during mass blasting and oversize crushing with various blasting schemes in various mining and geological and meteorological conditions have been carried out. Optimal conditions for organization and production of blasting operations are proposed.
Market economy not only establishes new economic relations between different enterprises, but also forces a different assessment and, consequently, the solution of certain technological problems. In particular, at the enterprises producing fractional crushed stone, the parameters of the main technological processes are calculated according to the factor of minimum cost. At such approach to designing overestimates output of unprofitable fractions, price and demand for which is much less than price and demand for deficit fractions. Therefore, as the basic criterion for designing technological parameters, it is necessary to accept the maximum profit from realization of production.
