The support in the bottom-hole zone of the trunk is a system of rings made of monolithic concrete having a different hardening period, which increases from the face up the trunk and is determined by the duration of the tunneling cycle. The strength and deformation parameters of the concrete support depend on the age of the concrete. Thus, to determine the strength of concrete in the early stages of concrete hardening, various empirical dependencies are used that link the strength of concrete at the design age with the strength at the required age. Based on a series of calculations performed by the finite element method, it was found that the change in the penetration rate does not significantly affect the relationship between stresses and deformations when static equilibrium is reached in the ""support – array"" system, which occurs at a high penetration rate at a greater distance from the bottom of the trunk. At the same time, intensive loading of the support at an early age can disrupt the process of natural hardening of concrete, lead to a violation of its structure, the development of fracturing, which will entail a decrease in the bearing capacity and water resistance of the support, a decrease in its durability.

Keywords: shaft, sinking, support, concrete, stress, deformation, strength, bearing capacity

This article discusses the modeling of a 4th order Butterworth bandpass filter, with the Sallen-Key topology, composed of 2 stages with a bandwidth from 31.5 Hz to 8.5 kHz, designed to work as part of a digital noise level meter . Modeling was carried out in a modern computer-aided design package Filter Design Tool from Texas Instruments. The simulation results are presented, a conclusion is made about the correspondence of the parameters of the simulated filter to the calculated ones. The filter has a satisfactory quality factor, amplitude deviation in the passband, is quite simple and economically acceptable from the point of view of its implementation.

Keywords: noise meter, bandpass filter, Butterworth filter, Sallen-Key topology, modeling, CAD

The author carried out the development of the measuring unit of the intellectual system for the protection of the territory. Based on the review of devices of a similar purpose, a block diagram of the device was developed. A functional diagram of the developed device based on the block diagram has been developed and described. The description of the computer experiment on modeling the operation of the input block of the circuit in Micro-Cap, its results and analysis is given.

Keywords: measuring unit, intelligent system, modeling, vibration, triboelectric sensor

in the course of designing a device for measuring the instantaneous velocity of plasma in an electrodynamic accelerator, a block diagram of the implementation of the developed method was developed. A mathematical description of the calculation of the instantaneous velocity of plasma in an electrodynamic accelerator is presented. The choice of a realizable method for measuring the instantaneous velocity of plasma in an electrodynamic accelerator using a differential-total-ratiometric coordinate function and approximating the position sensor signal by an inverse-exponential function is substantiated. Simulation of the computing unit of the device in the Micro-Cap environment has been completed.

Keywords: measuring device, electrodynamic accelerator, plasma velocity, differential sensors

The relevance of this study lies in the fact that the mutual influence of existing transport facilities and the newly erected underground part will be taken into account and the ways to minimize the geomechanical impact on each other will be determined. The subject of the study is the stress-strain state of the system ""structure - massif - structure"". The purpose of the study is to minimize the mutual influence of the subway, the railroad and the underground part of the designed building.

Keywords: geotechnical screen, mathematical modeling, FEM, underground structure, mutual influence, stress-strain state, subway station, minimization of influence

The article is devoted to assessing the influence of errors in the experimental determination of initial data by non-destructive methods for recalculating the bearing capacity of building structures. When conducting an inspecting procedure the technical condition of the building structures that have been in operation for a long time, one of the main tasks is to determine their current operational suitability and predict their durability. The author considers possible errors or inaccuracies in the measurements of the physical, mechanical and geometric characteristics of a reinforced concrete beam (concrete class and reinforcement parameters). The degree of their influence on the change in the bearing capacity of the beam is compared. The conclusion is made about the greatest influence on the actual value of Mult (up to 34.5%) occurs from an incorrect determination of the diameter of the working reinforcement. Errors in determining the class of concrete remain within 1%; accuracy of determining the thickness of the protective layer - within 1.5% and they have a significantly smaller impact on the value of Mult.

Keywords: inspection of existing structures, methods of non-destructive testing, calculating of bending structures, reinforcement parameters

In this paper, we study the process of heat conduction in a flat wall with an internal heat source under boundary conditions of the first kind. Various numerical and analytical methods are used to solve heat transfer problems. Each method has a number of advantages and disadvantages. The paper proposes to use the numerical method of finite differences. The original differential equation, as well as the boundary conditions, are approximated using a finite difference scheme. The essence of the method is to apply a spatiotemporal grid to the computational domain. For each grid node, a difference relation is written (the original differential equation with boundary conditions is replaced by the corresponding expressions obtained using the difference scheme). Solving this scheme, we obtain the temperature values ​​in the plate for each step in time and coordinate. On the basis of the solution obtained, graphical dependences of temperature on time and coordinates are constructed, and their analysis is carried out.

Keywords: finite difference method, thermal conductivity, plate, internal heat source, boundary conditions of the first kind

3D printing (3DP) is considered an innovation that promotes automation in civil engineering and offers advantages in design, sustainability and efficiency. With its potential to automate, eliminate formwork, reduce construction waste and improve geometric accuracy, 3DP has promising applications in the building construction and civil engineering. 3DP is an effort to put digital manufacturing into practice, enabling a direct transition from building design / modeling (BIM) to 3DP. This article provides various aspects of application in construction, materials and their compositions, as well as examples of the use of 3DP: buildings, structures, polymer sleepers, etc.

Keywords: 3D technologies in civil engineering and construction, materials

According to available literary and graphic sources, the components of urban space, its structural units and their methods of formation are analyzed. The possibility of forming public spaces inside buildings and structures by methods of forming urban spaces is revealed.

Keywords: space, microspace, mesospatial, macrospace, methods of formation, urban structure, public space, levels of spatial organization, public structure, formation of a public complex

The effect of a zeolite support on the physicochemical properties of cobalt catalysts prepared by the precipitation method and calcined at 400°C was studied. The values of the specific surface of the catalysts, the degree of cobalt reduction, and the dispersion of the metal were determined, and the presence of functional groups on the surface of the catalysts was determined by BET, TPV, TPD-H2, and IR spectroscopy.

Keywords: catalyst, cobalt oxide, hydrocarbons, dispersion, active surface

This article presents the results of a research work devoted to the use of ultrafiltration membranes in the technology of purification of natural waters and wash waters of a contact clarifier unit, as well as design proposals developed on their basis for the reconstruction of existing water treatment plants.

Keywords: membrane technology, ultrafiltration, membrane module, natural water treatment technology, flushing water treatment technologywater treatment facilities, patent research

This article discusses the advantages and perspective for the use of biogas in the conditions of the Republic of Crimea. The ecological and economic aspects of the use of biogas technologies at winemaking enterprises are touched upon. Describes the methods of using biogas at the winery "Massandra" in the Republic of Crimea. The calculation of the use of natural gas in the boiler house of a winery is made. A calculation was made for the use of biogas in a boiler house. It can be concluded that when using biogas in the boiler house of a winery, fuel needs are fully covered. The surplus of the remaining fuel is proposed to be used in a cogeneration plant to generate electricity.

Keywords: biogas, cogeneration plant, grape plant residue, recycling, interchangeability, granulate, natural gas, grapes, thermal energy, electricity, winery

The article presents the results of experimental studies of crack resistance of inclined cross sections of I-shaped beams using basalt fibre reinforced bars as a transverse reinforcement . The data of previously conducted experiments were studied and the test of own samples was carried out. The beams had the same geometric characteristics and differed from each other in the angle of inclination of the transverse reinforcement, the percentage of transverse reinforcement and the shear span to depth ratio. The influence of variable parameters on the load of formation of inclined cracks and the width of their opening is analyzed. In most cases, the width of the opening of inclined cracks does not exceed the permissible values established by the codes of different countries. The exceptions were mainly samples with the lowest percentage of transverse reinforcement.

Keywords: crack resistance, I-shaped beams, transverse reinforcement, inclined cross sections, shear span, basalt fibre reinforced bars, inclined cracks

The article considers one of the ways to improve the reliability of mining equipment, by eliminating sudden failures and reducing the severity of their consequences, based on the use of digital technologies and automated control systems for its technical condition and online diagnostics. It is proposed to use the methods of diagnostics and automated control of the technical condition of power electrical machines, which consist in monitoring the current with subsequent spectral analysis of the recorded signal. The method allows to determine the current technical condition of the engine elements with sufficient accuracy. A high-performance RISC microcontroller of the AVR ATmega16 family was adopted as the constituent elements of the diagnostic complex, which contains a fast Harvard processor, program memory, data memory, input / output ports and various interface circuits.

Keywords: reliability of mining equipment, diagnostics, automated control, current monitoring, spectral analysis

As part of the proper maintenance of a number of infrastructure facilities (right-of-way for roads and railways, protected zones of power lines, gas pipeline routes, etc.), work is being carried out on their territory to remove growing unwanted vegetation. The article discusses the features of determining the values ​​of capital investments for the formation of a system of machines, mechanisms and used mechanized and manual equipment for cleaning these territories from unwanted vegetation, shows an example of their calculation using specific brands of machines, mechanisms and equipment used in production, formulates a conclusion about the feasibility of introducing of the considered method into the production process of enterprises and organizations responsible for the maintenance of the indicated territories of linear infrastructure facilities.

Keywords: territory, unwanted vegetation, removal, mechanization, equipment, definition, capital investment