S. N. Zharikov's research while affiliated with Mining Institute of the Russian Academy of Sciences and other places

The authors assess blasting-induced seismic impact on underground openings in Magnezitovaya Mine, determine seismic stability and adjacent rocks and calculate safe distance of blasting based on the criterion of allowable seismic loads. The blasting impact testing was carried out using seismic recorders Uran and Minimate Plus with three-component seismic receivers. It is recommended on setting limiting mass of explosive per delay interval in underground blasting.

The article presents the studies into the impact of shock waves induced by underground blasting. The instrumental measurement of actual pressures at the shock wave front in air in Magnezitovaya Mine during blasting is performed. Using the measurement data, the safe distances of shock wave impact out of possible personnel injury risk are determined. The excess pressure at the shock wave front in mine air is calculated with regard to local pressure losses. The calculated excess pressures are compared with the maximum allowable pressures for personnel, timber cofferdams, ventducts, appliances and power lines.

The authors assess the effect of seismic vibrations induced by blasting in Biyanka gravel quarry and by movement of trains. The research was initiated in view of the accident in summer of 2017, which resulted in off-trip of two cars. The jointing structure of the rock slope is inspected, and the slope stability is assessed in some sites of the slope within the limits of the Asha railway haul. The recorded seismic vibrations in the rockfall-hazardous sites of the slope are less hazardous for the slope stability than the geological features of the slope, which are the cause of all rock falls. The recommendations on prevention of rock falls on the track are given.

The paper presents the results of a study of permissible dynamic load on high-pressure gas pipe laying site of the II category located within the mining lease boundaries, in connection with carrying out blasting operations at the open-pit mine of JSC Sukholozhsktsement. The procedure of IM UrB RAS for calculating the permissible distances from the technological explosion in the mine to the protected object (gas pipeline) depending on the explosive weight in the stage, coefficient of soil conditions and permissible velocity of seismic vibrations is presented. It is found that depending on the explosion depth in the mine and using corresponding geological data, by changing the weight in the delay stage, it is possible to completely eliminate the negative effect of explosion on pipe laying area. A calculation scheme is also proposed to determine the safe distances to high-pressure gas pipeline depending on the angle of open pit side and blasting depth.

The paper presents the research findings obtained by the Institute of Mining in drilling and blasting in Dzhetygara open pit mass. The research was aimed at enhanced stability of stationary benches and at cost minimization of drilling and blasting. The research met two objectives. First, in terms of Dzhetygara deposit, perimeter blasting designs were developed, which ensured reduced impact of blasting on adjacent rock mass. Second, the blast-induced PPV measurement procedure was refined and introduced, and the blasting technology was improved for blasting operations at ultimate pit limit. The special technology for ultimate pit perimeter blasting includes: analysis of blast effects on pit wall rock mass; finding of mechanisms of wave processes in rock mass; interaction of perimeter blasts depending on strength characteristics of rock mass; field trial of cutback methods; determination of sequence of blasts when approaching a guarded sites; determination of efficiency criteria of drilling and blasting.

In the paper, blasting seismic survey results for some mine blocks are given. Issues of studying the wave propagation processes in the rock mass and solutions to them are described specifically for mining engineers with minor theoretical deviations and emphasizing maximum practical significance. The method developed by the Mining Institute of the Russian Academy of Sciences Ural Branch to determine protective measures against the effects of blasting on protected objects depending on the explosive weight in delay, soil factors, and the permissible seismic velocity is described. Based on previously identified patterns for various soils, dependencies between the rock mass properties and charge parameters have been built and summarized in a nomogram to simplify the corresponding determination of the technical explosion parameters. The advantage of this approach, in contrast to others, is the possibility of a quick multivariate evaluation, which is of great importance for the prompt elaboration of technical solutions. In the paper, the specifics of determining the drilling & blasting parameters when approaching the marginal quarry zone are partially discovered and promising areas in studying seismic phenomena in rocks and the blast seismic for the nearest future outlined.