The drilling and blasting method is currently the most widely used for mining rocks. An indicator of the high–quality drilling and blasting operations is the uniform granulometric composition of the exploded rock mass - the percentage of oversized ore pieces should be minimal. The percentage of oversized and its increase have a significant impact on the technical processes of transporting rock mass, leading to an increase in the costs of loading and transportation operations and secondary crushing of oversized ore masses. The paper describes the results of a study of methods for determining the granulometric composition of drilling and blasting operations using neural networks of segmentation Unet and FPN. Images taken from UAVs are used for analysis. A method of classifying ore by size has also been developed, which ensures the accuracy of the proportion of correct answers of more than 0.91. The expected result of the introduction of the system for automatic determination of the granulometric composition of drilling and blasting operations is the possibility of more accurate control over the quality of their performance.

Keywords: granulometric composition, Unet, FPN, classification, segmentation

Tests to determine the seismic stability of elements of pipeline systems, in particular pipeline fittings, are included in the list of those necessary to confirm the operability of the element. In this study, a stand was developed for testing to determine the seismic stability of butterfly check valves, which are a type of pipeline fittings. A finite element analysis was carried out, data on maximum deformations, stresses and displacements of structural elements were obtained, and the response of the installation table to seismic impact was calculated. The resulting displacement values of the table structure do not exceed the limit values specified by the technical requirements and do not lead to distortion of the structure or destruction of joints, which makes it possible to move from design to manufacturing and commissioning of the stand.

Keywords: vibration tests, seismic resistance test bench, pipeline, pipeline valves, swing back gate, mathematical modeling, finite element method, strength calculation, simulation modeling, stress-strain state

Due to the constant increase in production, new structural materials development and growing rates of non-renewable resources consumption, the issue of increasing the machinery resource is urgent. Thus, it is necessary to develop technologies for spraying coatings that improve the functional characteristics of products, in particular, impact strength, microhardness, resistance to wear, corrosion and other environmental factors by modifying the surface layer structural-phase state. These technologies application is necessary in strategically important industries, such as machine tool manufacturing, aerospace, automotive, shipbuilding, chemical, energy, etc. This article is devoted to the facility development for multicomponent nanocomposite coatings sputtering. The design and commissioning of such a facility requires a high time and material resources investment. In this regard, it is necessary to use modern computer software systems that allow simulating multiphysics processes that take place during the facility operation. The simulation of the cathode-anode unit was carried out. Based on the simulation results it was shown that it is necessary to take into account the physical processes in the interelectrode region when designing the plasma spraying unit, since the resource of the cathode-electrode unit and the productivity of the sputtering process directly depend on the parameters of the discharge and the resulting plasma jet. Thus, high temperature and current density, as well as the arc spot abrupt movement, lead to increased wear and failure of the copper nozzles. The maximum values of the temperature and velocity of the plasma jet during spraying were 32000 K and 1800 m/s, respectively.

Keywords: plasma spraying, multicomponent nanocomposite coatings, multiphysics processes, mathematical modeling

As a result of the analysis of normative documentation and soil fixing works, a brief historical review of the physicochemical methods of soil fixing was presented. Examples of the application of these methods in Russia and the world are considered.

Keywords: subsidence soils, cementation, soaking, heaps, mudding, subsidence, deformation, pit, soil consolidation

The article focuses on radiowave propagation in complex conditions combining rough terrain with woodland or urban areas. The estimation of influence of all these factors on signal attenuation may be challenging. Consequently there are no propagation models for such environment for distances up to several kilometers. However by approximating the experimental data on radio wave attenuation it is possible to develop empirical propagation models for specific cases. The authors carried out a series of experiments to measure the level of radio signal at a given distance from the source. Based on the experimental results a hybrid model for rough terrain, wooded and urban areas for ground communications systems was developed.

Keywords: radiowave propagation, UHF, experimental study, rough terrain, urban area, wooded area, empirical model, radiowave attenuation, path loss, ground mobile communication

The calculations and assessment of the impact of the built dormitories on the design of the existing building in accordance with the requirements of SP 22.13330.2011 and techniques of the FEM program Plaxis 2012.01 (Build 8962)

Keywords: pile foundations, Plaxis program, Geology