The article deals with the question of the effect of explosive characteristics of emulsion explosives on the shotpile width. Currently, there are two main points of view to select an efficient type of explosive, which contributes to the qualitative destruction (fragmentation) of coarse clastic rocks. The first is based on the assumption that the detonation velocity of explosives must correspond to the break-down point of the rock (dynamic compression). Another point of view is that the detonation pressure of explosives determines only the head part of the pulse, on which the rock fragmentation is dependent only near the charge, in the contact zone around the borehole. The fragmentation of the entire rock volume within a given borehole array depends on the total magnitude of the explosion pulse, determined not by the detonation velocity, but by the total energy reserve of the explosive charge. Experimental explosions with some of the most common industrial explosives have been carried out in the current conditions of blasting of borehole charges by various types of industrial explosives from the point of view to select the most important parameter, which determines its influence on the shotpile width The investigations have been carried out according to the data obtained to establish that the energy properties of explosives (heat of explosive transformation and density of explosives) determine the decisive influence on the shotpile width, and the operability, the volume of the released gases, the detonation velocity for the change in the shotpile width have very little effect and may not be taken into account in calculations for the prediction of the shotpile.

The analysis of methods for determining the permissible speed of seismic vibrations of the soil at the base of the protected objects of Satka town. The maximum permissible values of the rate of vibration of the soil were determined for the buildings and structures of the industrial site of the Karagaiskiy quarry of the mining enterprise PJSC “Kombinat “Magnezit” (buildings of the administrative household plant, underground steel water pipeline, pump station), as well as for residential and industrial buildings. Approximating functions are constructed and empirical correlation equations are obtained for the mining and geological conditions of the Karagaiskiy quarry, confirming the equation of M.A. Sadovskiy. Actual seismicity coefficients and seismic wave attenuation indices were determined based on instrumental measurements of the speed of seismic vibrations of soil at positive and negative rock temperatures from 2004 to 2019 for the geological conditions of the Karagaiskiy open pit in order to refine and evaluate the seismic safety of residential and industrial buildings, structures and natural infrastructure facilities of Satka town, Chelyabinsk region. Design decisions on the seismic safety of guarded facilities during blasting operations in cramped conditions during mining of the north-western section of the Karagaiskiy quarry were confirmed and the parameters of drilling and blasting operations ensuring the seismic safety of guarded facilities were clarified.

Seismic impact of technological explosions on underground mining workings of the Magnezitovaya mine was assessed. Seismic stability of rocks of the Magnezitovaya mine was determined and safe distances from technological explosions have been calculated by the admissible seismic effect for rocks. URAN and Minimate Plus seismic recorders with three-component seismic receivers were used to establish the dynamic impact on the mine workings. Based on comparison of calculated values and experimental measurements, the recommendations are given for explosive mass limitation at a slowing-down stage at a level of minimum dangerous values for technological explosions in underground mine. It is established that the blasting operations carried out at the Magnezitovaya mine of PAO Magnezit Combine with fan longhole stopping were performed with the seismic impact safety of underground technological explosion and will not lead to the loss of rock mass stability near the underground workings. Relevance of these studies is to ensure industrial safety of underground mining operations.

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