The article considers the work of a reinforced concrete beam lying on an elastic half-plane. The strength of concrete is considered as a random variable, while the initial modulus of elasticity of concrete and, accordingly, the initial stiffness of the beam are taken as functions of the random cubic strength of concrete. The base of the beam is considered as an elastic stochastically inhomogeneous half-plane. Using the method of canonical expansions of random functions, the probabilistic parameters of the probability distribution densities of beam deflections, as well as bending moments and transverse forces in a reinforced concrete beam, which are non-stationary random functions, are obtained. This makes it possible to further determine the probability of occurrence of limit states in a reinforced concrete beam.

Keywords: reinforced concrete beam, initial stiffness, cubic strength, inhomogeneous half-plane, distribution density, beam deflection, random function

The article considers the impact of wind flow on buildings and structures. The analysis of the influence of wind pressure on buildings of various shapes is carried out. The three main effects of wind occurring around wind-sensitive buildings are indicated. A comparison of three building forms was made. It is established that the round shape of the building in the plan has a smaller moment of resistance from wind gusts and from the force of resistance. It is determined that these parameters are higher in the case of square and rectangular buildings.

Keywords: wind, pressure, load, urban ecology, building shape, aeration, urbanization, ecoclimate

The article discusses modern methods for protecting load-bearing structures from progressive collapse, as well as methods for their calculation in extreme conditions, in order to ensure the safety of buildings and structures, reduce material damage and minimize human casualties as a result of emergency situations. The main purpose of the work is to identify the imperfections of existing methods for calculating building structures against progressive collapse, regarding multi-storey residential complexes, which are characterized by girderless frames, which have significant architectural advantages, as well as revealing the inaccuracies of empirical formulas used in practice for determining the coefficients of dynamic strengthening in tension and compression, which entails a calculation that does not correspond to the actual work of structures.

Keywords: beamless frame, progressive collapse, protection measures, calculations, dynamic coefficient, dynamic strengthening coefficient

Currently, artificial intelligence is gaining more and more development in various sectors of the national economy. However, he is not able to function without the control of a person and helps him in solving a narrow range of tasks. In the article, based on the analysis of leaders in the implementation of AI, the prospects for its development are considered. The role of company management in projects for the implementation of AI tools and methods is emphasized. The possibilities of introducing AI methods in the construction industry are considered. It is proposed at the initial stage to apply machine data processing to solve logistics problems. The main stages of the implementation of AI elements for construction organizations are proposed.

Keywords: artificial intelligence, construction, supply, material resources

Co-branding contributes to the creation of more successful products. Purposeful formation of the image of an architectural object, that is, its brand, consists of three parts. Its creation involves the brand of the organization or organizations located in the building, the brand of the author or authors of the project, and the brand of the place. These three components can manifest themselves in different ways in an architectural object. Studying the issues of joint branding of architectural objects and understanding this process is important not only for architects and developers, but also for other professionals. The realization of the possibilities hidden in this area contributes to the creation of a holistic image of an architectural object.

Keywords: building image, place brand, building brand, architecture, co-branding, logo, trademark

This article is devoted to some features of the performance of engineering and technical inspection of chimneys made of brickwork. The relevance of this research topic is due to the presence in our country of a large number of functioning chimneys made of brickwork, whose age exceeds 50 years, while a clear algorithm for performing surveys, taking into account all possible types of defects and features of performing verification calculations of these structures has not yet been developed. The author of the article substantiates the relevance of this research topic, presents the types of defects characteristic of brick chimneys, and also briefly describes the features of performing verification calculations of these structures when performing their engineering and technical surveys.

Keywords: inspection of building structures, exhaust shafts from brickwork, chimneys, brickwork, flaw detection of chimneys, flaw detection of building structures

Mechanical systems oscillate relative to the equilibrium position, and their amplitude depends on both frequency and mass, shape, design and mechanical properties of the system. There are two parameters of the grequency response of mechanical systems: the frequency of their natural vibrations and dynamicity on the effect of forced vibrations (dynamic coefficient). The purpose of the article is to investigate methods for calculating the parameters of the frequency response such a frequency of natural vibrations and the dynamic coefficient of a cantilevered steel beam. The methods which were used are analytical, finite element method with the ANSYS software environment and experimental method on the vibration stand with two loading methods: sinusoidal vibration using the swinging frequency method and broadband random vibration. The obtained natural oscillation frequency values are consistent within the relative error of 15%, dynamic coefficient values are consistent within the relative error of 5%. The finite element method is well consistent with the analytical method, while it requires fewer operations for more complex designs. Differences in the results of experiments arise from differences in the methods of loading the object of research.

Keywords: frequency response, finite element mathod, ANSYS, natural vibrarion frequency, sweep check, broadband random vibration

The application of the gas-dynamic method with the use of nonlinear dynamics to the calculation of an underground structure built into the lower floor on the impact of an air shock wave is considered, taking into account the collapse of the above-ground part of the building. It is known that one of the impacts on built-in underground structures designed to protect the population and territory from natural and man-made emergencies is the impact of a possible collapse or blockage from a higher building when exposed to an air shock wave. This task is relevant because the current methods are based on linear static calculation methods and involve certain assumptions, including when calculating for collapse, and all this can lead to difficult to estimate errors in the calculation results. Therefore, when solving these problems, which are highly non-linear and the processes under consideration themselves are fast, it is necessary to consider the use of more adequate and accurate methods based on more rigorous formulations, which is the gas-dynamic method using nonlinear dynamics.

Keywords: emergency explosive effects, air shock wave, impulse effects, non-linear gas dynamics, compression phase, rarefaction phase, underground structures, “Ambient” elements, Eulerian grids, progressive collapse, collapse of structures, destruction of structure

The article describes four developed designs of samples of joints of solid wood elements on aluminum linings. They made it possible to simulate the operation of real connections of the main and secondary beams, as well as crossbars and columns. Tests of connection samples were carried out, one of the four developed variants of sample designs was selected that most fully reflects the actual work of real joints of wooden elements. The strength and deformation characteristics of the joint, the upper boundary of the elastic work area (VGOUR) of the joint are determined. Based on the conducted research, the peculiarities of the work of the studied compounds were determined, a sample of the connection of a wooden element with a metal overlay was developed, which allowed the development of measures aimed at increasing the bearing capacity and reducing the deformability of the studied compounds without significant material costs associated with the purchase of expensive SHERPA linings.

Keywords: solid wood, metal slips, testing of joint specimens, joint bearing capacity, joint deformability, upper limit of the elastic work region, full deformation, permanent deformation, elastic deformation, safety factor

The article presents the results of the calculation of a steel truss with parallel belts with a span of 36 m for the second group of limit states, taking into account the selected share of the temporary snow load duration. The comparison of the results of determining the vertical displacements of the steel truss structure nodes under the action of permanent and temporary snow loads is carried out.

Keywords: truss, calculated combination of loads, modulus of elasticity, stiffness, fraction of duration, deflection, CAD

The article considers the method of applying dynamic effects on cylindrical mesh roofs. The necessity of taking into account oscillatory processes from operating devices and in case of mechanical failure of the attached equipment is justified. The features of the construction of structures and the location of static loads are taken into account. A specific numerical example is given in the framework of application software application. A rational grid shape with a diagonal element in the middle is adopted and acceptable ratios of geometric parameters are obtained. The defining mathematical dependencies are indicated and the dynamic load modeling process is shown. Direct integration of the equations of motion is carried out. The regularities of the influence of oscillatory processes on the operation of the roof are revealed and a visual visualization of the results is obtained. Extreme values of force factors and parameters of deformation of the structure at a given time interval are recorded.

Keywords: cylindrical mesh roof, direct integration of equations of motion, dynamic impact, force factor, deformation parameter

The work of new Russian regulators RED is being considered. The results of a study of the compliance of regulators with the declared class of locking pressure using the "PLEXOR" installation are presented. The conducted tests show that Russian gas pressure regulators in the conditions of import substitution are not inferior to foreign analogues in their technical and functional characteristics.

Keywords: gas reduction point, pressure regulator, locking pressure class, diagnostics, setting limits

The issues of seasonal unevenness of gas consumption for the needs of heating, ventilation and hot water supply of the shopping and leisure complex are considered. Calculations of volumetric and power indicators of uneven gas consumption for 2020-2022 are given according to the data of the archive of gas consumption meters.

Keywords: gas consumption, uneven gas consumption, volume, capacity indicators, shopping center

The construction complex should become one of the main drivers of the Russian economy's recovery from the crisis. In order for the industry to achieve maximum returns, it is also necessary to reduce administrative barriers as much as possible. The reform of control and supervisory activities in the Russian Federation is aimed at accident-free, both construction and operation of facilities under construction. An example of the correctness of the appointment and compliance with the requirements of technical regulations, the results of engineering surveys at a site with complex engineering and geological conditions is considered: seismicity, subsidence for compliance of engineering surveys with the requirements of legislation, technical regulations, design and regulatory documentation.

Keywords: control and supervision activities, requirements of technical regulations, complex engineering and geological conditions, engineering surveys

The method of determining crack-forming forces based on the normative approach is considered. Experimental and theoretical studies of reinforced concrete beams made of ordinary heavy concrete, self-compacting concrete with a modifier and concrete of a frame structure have been carried out. Formulas for determining the tensile strength and flexural strength depending on the compressive strength for each of the considered types of concrete are given. The calculated values of the ultimate extensibility of various concretes determined by various methods are given. Coefficients to the formula linking the reduced and initial elastic modulus of various types of concrete are obtained. The influence of the accuracy of the experimental determination of the moment of cracking on the change in the calculated dependencies is analyzed.

Keywords: cracking moment, flexural and tensile strength, frame structure concrete, self-compacting modified concrete

One of the most massive polymer waste of consumption is car tires that are going out of service. The disposal of such tires at a solid waste landfill is an extremely inefficient way of their disposal, entailing an increase in the area of landfills and an increase in negative environmental impact. The least financially and labor-intensive way of processing automobile tires is grinding into fractional crumbs. To reduce the costs of sorting and further grinding of tires, a shredder with a dispersion of 3 mm is used. The article suggests the use of rubber crumbs as a binder when laying highways. Studies of indicators affecting the operational parameters of asphalt pavement at different values of the mass of rubber crumbs in comparison with a clean sample were carried out and the optimal specific mass of the added crumbs was determined, which was 15-20%.

Keywords: rubber crumb, tires, asphalt mix, optimal weight

Abstract: This article discusses the prospects and problems of the development of digital technologies in the construction industry of the Russian Federation. The work presents the main legislative acts and federal projects aimed at the digitalization of construction in the country, the features of the introduction of digital technologies at all stages of the life cycle of capital construction projects, including: building information modeling (BIM), their digital twins (Digital Twin), the Internet of things ( IoT), with the help of which a single information space is created that allows collecting, systematizing all the received data, on the basis of which management is carried out at various stages of the life cycle.

Keywords: digital transformation, construction, building life cycle, BIM technologies, Digital Twin

The trends of modern society require a quick solution to the issues of restoration of emergency buildings and structures. New methods of strengthening the load-bearing structures of buildings are aimed at reducing labor costs, the timing of work and the need for complex equipment. In the field of reinforcement of reinforced concrete structures, such methods are composite reinforcement systems. Having proven itself well in working with bendable and compressed elements, there are areas where their use has not yet been studied. One of these is the reinforcement of reinforced concrete girderless floors, in which the protective layer of concrete is broken. This article is devoted to the development of a method of reinforcement with composite materials, where the protective layer of concrete was violated. At the same time, the internal moment of a pair of forces reduces the bearing capacity of the element by about 30%. The paper presents the advantages of the new composite reinforcement method and provides a possible example of its use on a real object.

Keywords: concrete, reinforced concrete, composite material, carbon fiber, carbon fiber lamellas, carbon laminate, flexibility, compressed elements, girderless overlap

The article contains the results of verification of the finite element design model of work on axial compression of reinforced concrete structures with combined reinforcement. Structures with combined reinforcement (with non-removable steel-fiber concrete formwork) are widely used in the construction of nuclear power plant structures. Steel fiber reinforced concrete, in comparison with heavy concrete, has increased strength and deformation characteristics, due to which it performs the function of a bearing element that perceives compressive and tensile forces. The study of the joint work of steel fiber concrete and heavy concrete is a promising area of research. The developed finite element model of a reinforced concrete structure with a fixed steel-reinforced concrete formwork with a high degree of reliability allows us to determine the stress-strain state, the redistribution of forces between the cross-section elements and the parameters of cracking during loading. The described modeling technique is recommended to be used in the study of the operation of such structures.

Keywords: NPP, nonremoveale formwork, structural testing, Ansys, stress-strain state diagram, steel fiber reinforced concrete, finite element method

The article considers an experimental study of the stress-strain state of radial beam domes. The maximum stress values are fixed in stretched flexible elements with a peak value of 363.6 MPa. With the calculated resistance of the wire material Bp-I Rs = 410 MPa, there is a 12% load-bearing capacity margin. Note the high level of stresses in other flexible elements with values in the range from 141.4 to 274.72 MPa.

Keywords: radial beam dome, experimental studies, loading, strain gages, deformation

A monolithic plate is the most reliable type of foundation. The design is selected if the future building or structure will stand on a site with difficult soil. Three variants of organizational and technological solutions are considered - a ribbed foundation plate a solid foundation slab and a box-shaped foundation plate For each technology, two options for reinforcement are considered - steel and fiberglass reinforcement. The analysis of existing technologies for the installation of a monolithic foundation plate carried out in the first section of this work, showed that the use of these technologies is hampered by a number of factors related to the design and technological features of the object being built. The choice of a rational technology for the installation of a foundation plate is carried out by assessing the influence of organizational, technological and design factors. Based on the results of a comparative analysis of the methods for constructing a foundation plate, it was revealed that the most rational in terms of labor intensity and cost for the structure under consideration, a reinforced concrete plate 15.6x544 m, is technology No. 1 - a ribbed foundation plate using MSC formwork and reinforcement with fiberglass reinforcement. The analysis of the dependencies obtained and the calculation of the coefficients showed that the factors affecting the laboriousness of the installation of a monolithic foundation plate can be arranged in the following order in terms of significance: 1) structural characteristics (the presence of ribs, a solid slab or the presence of voids); 2) thickness of the foundation plate; 3) type of reinforcement used for reinforcing the foundation plate; 4) the area of the constructed plates.

Keywords: monolithic foundation plate, steel and fiberglass reinforcement, factorial analysis, labor intensity and cost of construction, work performance

This paper presents, developed by the authors of this scientific article, a method for calculating the strength of reinforced concrete out-of-center compressed racks according to the current regulatory methodology according to SP 63.13330.2018. The peculiarity of this technique is the condition that when calculating the strength, an external force is unknown, in turn, the normative methodology, on the contrary, is focused on calculating the cross-sectional area of metal reinforcement, provided that an external force is known in advance. The inverse problem is not provided for by the norms, since it is used mainly for scientific purposes. Consequently, the methodology developed by us is of great value for research work, where an important factor is the determination of the strength of samples for subsequent comparison with the strength of the corresponding reference samples and the development of new proposals for calculation methods. For the convenience of the reader, the developed calculation method is presented as an example of calculating the strength of one off-center compressed reinforced concrete sample, with explanations and references to the formulas of the normative literature. The calculated sample was actually manufactured and tested in the laboratory of the Department of Housing and Communal Services of DSTU and all its characteristics were found experimentally, therefore, the calculation method is based on comparison with the results of experimental studies.

Keywords: steel, heavy concrete, reinforced concrete, test, rack, eccentricity, strength, off-center compression

The design of energy-efficient buildings is based on the analysis of the external climatic effects on buildings for various purposes, the parameters of the air environment inside which are well defined. Climate systems of buildings should neutralize the negative impact of the external environment, in particular wind exposure. It determines both the temperature regime of the room and the purity of the air inside them. The complexity of both theoretical research and the organization of field experiments or blowing models of buildings in a wind tunnel makes it necessary to resort to mathematical modeling of the wind impact on the school building based on the StarCCm+ program. Velocity fields were obtained for different directions of wind load, the excess heat loss of the building in certain directions was determined. The possibility of conducting such studies in a wider range of initial and boundary conditions is shown.

Keywords: aeration of residential buildings, mathematical modeling

The use of information modeling at all stages of the life cycle of a construction object requires a revision of existing approaches to organizing the work of specialists, a more thorough study of the processes of information exchange, the search for new more effective ways of managing information and organizing the use of models. By the period of operation of the constructed object, a significant amount of various data and documents is generated, and during the operation of the building or structure there is a need to collect and analyze significant amounts of information. Damage detection and prediction of structural behavior, search for the current location of a building element can take a lot of time, and a systematic approach to information flow management will ensure an increase in the efficiency of operation services by reducing costs during unscheduled repairs and increasing the life of buildings. This article discusses a model of the integration process of data received or transmitted by Radio Frequency Identification technology tags and data stored and used in an information model. Tags can be placed on critical structures, in complex nodes or on cracks to monitor their disclosure. The approaches to managing information flows depending on the tasks solved at the operational stage, taking into account the preventive maintenance of building elements, are given.

Keywords: radio frequency identification, building information modelling, building maintenance, digitalization, internet of things, industry foundation classes, maintenance and repair, building condition analysis

The article presents a review of research on the subject of the special limiting state, which are of interest for the development of theory and practical applications. The results of the main works, which have not lost their relevance, are briefly presented. Perspective directions of development for improvement of the theory of the special limiting state are distinguished: 1) Taking into account in calculations the stiffness of nodal couplings, individual elements of structures. 2) Consideration of joint operation of prefabricated and prefabricated-monolithic structures, including shear stiffness of compound sections. 3) Consideration of temporal and spatial nature of impact. 4) Work on extension of application of the theory beyond calculations for progressive collapse.

Keywords: special limitstate, special effects, reinforced concrete, deformability, special limit state criteria