Methods for calculating technological and functional tolerances in the manufacture and installation of steel structures are described. An experimental installation of the structure was carried out to make it possible to clarify the tolerances, and the foundations of the methodology for assessing the qualitative and quantitative manufacturability of assembly elements were put forward to simplify the processes of manufacturing and assembling the structure.

Keywords: methods for calculating tolerances, installation of a structure, manufacturing of structures, manufacturability, complex indicator of manufacturability

The loads on the power floors and column foundations of modern logistics centers can reach 6-9 t/m2 and 1000 t, respectively. At the same time, the step of the grid of exploration wells in the mined areas does not allow reflecting on the geological sections the exact geometry of the occurrence of weak, untreated soils of backfilling pits. The use of a method for strengthening man-made soils by pressing in prefabricated prismatic piles made it possible to compensate for the missing information from engineering and geological surveys by controlling the forces of indentation and thus determining the occurrence marks of more durable foundation soils.

Keywords: engineering and geological surveys, the territory being worked on, man-made soils, soil reinforcement with piles, geological section

The article raises issues of repair and construction work on the installation of underground utility pipeline networks in urban environments. The sphere of housing and communal services today is characterized by the presence of high wear and tear of communal pipeline networks: sewer systems, water supply systems, energy systems, etc., which requires urgent measures to solve this problem as part of the implementation of urban reconstruction projects.

Keywords: repair and construction work, municipal pipeline networks, urban services, utilities, housing and communal services

The problem of quality in construction and installation works at intermediate stages is being discussed. The role of technical supervision in the construction process is outlined. A proposed indicator, the "Quality Index," is presented for consideration, which reflects not only the quality of the works but also the effectiveness of the technical supervisor's work during the construction process.

Keywords: quality, construction quality, construction quality index, quality coefficient, regulations, technical supervisor engineer

A more adequate methodology for assessing the overall risk of untimely completion (construction and installation works - CIW), taking into account the time horizon of risk occurrence and the phenomenon of risk competition from both probability and impact perspectives, is justified. One of the most common problems in construction projects is delays caused by risks. However, existing research on risk assessment and project schedule analysis overlooks the fact that the aggregate risk depends on the sequence of risk occurrences and their interactions. This article presents a decision algorithm and justifies a computational method for determining the risky duration of work in the project schedule. This information is crucial for making adjustments to the schedule and developing effective risk response strategies. In the calculation examples we have provided, we have demonstrated that our approach differs from the classical method.

Keywords: "probabilistic planning, delays, aggregate risk, risk assessment, uncertainty, construction management, quantitative analysis, timelines, investment projects"

The results of research permissible longitudinal axial and fiber tensions are given for various characteristics of gas distribution and gas consumption systems.

Keywords: polyethylene gas pipeline, longitudinal axial tension, longitudinal fiber tension, gas pipeline deformation, optimal gas pipeline bending radius

The article is devoted to the use of renewable energy sources, namely geothermal energy for home heating. Methods of installation, advantages and disadvantages of geothermal heating are investigated. A comparative analysis of the cost of 1 MJ of heat received from various energy sources was carried out, and the efficiency of using heat pumps for heating buildings was proved. It was noted that in connection with the global problem of greenhouse gas emissions, this decision is relevant and paramount for achieving hydrocarbon neutrality. The introduction of geothermal heating methods can be a huge step towards green energy.

Keywords: system, temperature, geothermal heating, heat pump, compressor, evaporator, condenser, carbon footprint, ecology, green energy

The development of an automatic system for installing a magneto-optical magnetic field sensor in a neutral position has been carried out. Installation in the neutral position is carried out by an automatic piezoelectric drive control system based on a microcontroller. A mathematical model is constructed and numerical simulation of the automatic control system is performed. The results and parameters of the simulation are presented. The developed system provides a significant increase in the autonomy of the sensor, which makes it possible to eliminate or significantly reduce the cost of regulating the sensor.

Keywords: magnetic field sensor, magneto-optical sensor, automatic control system, piezo motor

The concept of vertical expansion of development is becoming more and more popular in Russia, especially in large cities due to the scarcity and high cost of building land. This article continues the study presented in the material on the choice of a variant of the technology for constructing an operated roof, designed to be used, for example, as a recreation area, sports grounds, landscaping, etc. The article presents the results of a comparative assessment of the technological efficiency of the operated roofs construction, arranged with a traditional and inverse arrangement of a waterproofing carpet and thermal insulation. In the study, methods for evaluating their organizational and technological solutions based on technological efficiency indicators were applied. In addition, examples the systems engineering assessment tools use is provided. Determination of the manufacturability degree for the operated roofs installation on the basis of some system-technical principles and optimality criteria when comparing different options for organizational and technological solutions. Based on the calculation of performance indicators, a set of indicators with different dimensions arises. They are used as input for aggregate analysis when applying systems engineering. This approach allows achieving internal compatibility between the elements of the system, in this case, the obtained performance indicators. The technological advantages of the inversion installation of an exploited roof, in particular, intended for landscaping, have again been confirm.

Keywords: exploited roof, vertical gardening, inversion roof technologies

The article discusses the peculiarity of determining the duration of laying concrete mix depending on the height of the installation horizon. As a result of the study, the design was justified, which was accepted as a representative object, a sample of standard values of machine time costs was performed depending on the height (number of floors) of the building, the dependence of the calculated value of machine time costs on the height of the floor (the horizon of the work) was obtained, the reliability of the calculated values was estimated.

Keywords: monolithic construction, concrete works, labor intensity of work, duration of work, installation horizon, tower crane

The lack of clear recommendations in the regulatory and scientific literature on laying a heating network in an impassable channel not only increases the construction time, but also leads to serious design errors, which entail a decrease in the service life of the engineering network and the occurrence of emergencies at the facility. In this article, a methodology for a numerical experiment of laying a heating network in an impassable channel was developed, an experiment was planned with the choice of controlled factors. Data processing and analysis of the reliability of the results were carried out in order to simplify construction in urban conditions.

Keywords: channels of heating mains renovation, stressed-deformed state, methodology, numerical experiment, closed channel, experimental planning theory, finite element method, mathematical modeling, "black box"

The operability of an optical device depends entirely on the quality of the optical parts that make up the optical system. Timely measurement of errors of optical parts in the process of surface shaping organizes feedback: the more accurately the error is measured, the more accurately the correction of the geometry of the surface is possible. Errors of optical surfaces and optical systems in general can be estimated by the mismatch of coordinates of real and ideal (calculated) profile curves of surfaces; mismatch of normals to this surface; difference of wave fronts in incident and refracted (or reflected) beams of light rays, etc.. The reproducibility of optical surfaces from sample to sample and their compliance with the calculated one is usually estimated by the discrepancy between the actual and theoretical functions of the course of light rays. Such a discrepancy is estimated by the aberrograms of optical systems, which are determined experimentally on special installations – aberrographs. Unlike the known schemes for measuring longitudinal aberrations of only reflectors or only lenses, the devel-oped installation is universal, designed to measure zonal aberrations of large-diameter mirror and lens lenses that are used in lighting devices, solar energy concentrators, transmitting and receiving optical systems of optoelectronic de-vices.

Keywords: aberrometer, aberrogram, longitudinal aberration, lens lens, mirror lens

The paper presents the properties and nomenclature of products made of ceramic fiber used for insulating lining in steam reforming furnaces. On the example of the lining of the radiant chamber, the technology of mounting ceramic blankets on anchor studs, which is currently used in the construction and repair of reforming furnaces, is considered. The shortcomings of the existing technology are noted. These include the complexity of the process, the complexity of installation control and the high probability of uneven thermal conductivity of the lining surface due to hidden defects, as well as the spraying of ceramic fiber particles in the air that cause diseases. The nomenclature and technology of installation of insulating lining with ceramic blocks along guide tubes with subsequent resistance welding with the camera body is proposed. The technology will reduce the repair time, improve the thermal conductivity of the camera, reduce the risk of diseases.

Keywords: gas reforming, radiant chamber, insulation lining, ceramic fiber, thermal conductivity of the furnace

Pipe fittings, which are one of the main elements of any type of pipeline networks, can be used for various purposes: shut-off, reverse, safety, control, separating, shutting off, etc. In order to control the performance of this element, it is necessary to carry out various tests in the prescribed manner, the main ones being pneumatic. This study is devoted to the development of equipment for in-plant pneumatic testing of rotary check valves for pipeline systems of hazardous production facilities with ultra-high parameters of the working environment. For this design of the installation, the simulation of the stress-strain state of the elements of the installation was carried out, as well as the gas-dynamic calculation of the test circuit of the installation.

Keywords: rotary check valve, pipeline fittings, pipeline system, mathematical modeling, finite element method, strength analysis, stress-strain state, computational fluid dynamics, pneumatic testing, technological pneumatic installation

The article is devoted to the control system for the process of moving textile material in an apparatus for impregnating fabrics with periodic action. The control is implemented using a programmable logic controller (PLC). We consider a program developed in the Ladder Diagram (LD) programming language that implements motion control taking into account the change in torque.

Keywords: solution, immersion, technological process, algorithm, programming language LD