The article provides a review and systematisation of works devoted to the application of machine learning for solving problems of research, calculation and design of reinforced concrete structures. It considers the aspects, which are relevant today, related to calculation, design, as well as assessment of the technical condition of objects with the help of various approaches that implement machine learning schemes, including deep learning, ensemble algorithms. It is shown that nowadays in the world construction science this area is rapidly developing and improving. Thus machine learning algorithms solve problems of prediction of design parameters, problems of identification of these or those parameters, defects, damages on the basis of classification algorithms and others. The materials presented in the article will allow specialists to choose the subject area of research more precisely and determine the directions of adaptation and improvement of their own developments in the field of machine learning.

Keywords: machine learning, reinforced concrete structures, regression equations, identification, approximation, artificial intelligence

The article considers the causes of the formation of defects to be evaluated. The methods of obtaining information about the condition of metal corrugated pipes are presented. The main defects arising during the operation of metal corrugated pipes are shown. The most effective methods of assessing the condition of metal corrugated pipes have been determined.

Keywords: corrugated metal pipes, wear, durability, defects, factors, evaluation

A comparative analysis of the lighting conditions of school premises was carried out based on design solutions for lighting devices from three Russian lamp manufacturers. All projects were carried out using lighting devices based on recommendations to manufacturers to use their range of lamps to illuminate various school premises. The design was carried out using the DIALux program. Each of the three manufacturers is widely known to specialists and has established itself as a reliable manufacturer of domestic lighting products, ready to offer a full range of lamps for various school premises. A technical and economic comparison of the total present costs for all lighting installations (using the example of one entire school) made it possible to conduct a comparative analysis and determine the most profitable options. An analysis of the current state of the Russian market of lighting devices recommended by manufacturers for classroom lighting has been carried out, their characteristics have been reviewed, and their compliance with current energy efficiency requirements has been assessed. Conclusions and forecasts have been made for the further development of lighting equipment with LEDs for lighting classrooms, based on the need to constantly improve the modern range of lighting devices in terms of their energy efficiency and competitiveness.

Keywords: technical and economic comparison, levelized cost method, comparative analysis, school lighting, lighting device, lighting modeling, energy efficiency

The article presents a method for determining the stress-strain state of pile foundations for metal supports of power transmission lines during technical examination of power grid facilities in the Far North. An example of calculation using the LIRA automatic software package is given. The most stressed sections of structures are determined. The prospect of using CAD during technical examination of power grid facilities is proved.

Keywords: building structures, metal structures, energy facilities, stress-strain state, technical expertise

The article provides a brief overview of foreign experience in the application of information modeling technologies (BIM) in "green" construction. The work carried out a scientometric assessment of publications on the topic of BIM in "green" construction. As a result of the review, it was found that BIM has recently been increasingly used in the field of "green" construction, forming a new stage of resource efficiency and minimizing the negative impact on the environment.

Keywords: information modeling technologies, "green" construction, sustainable development, building life cycle, resource management, energy efficiency and environmental friendliness

The development of methods for calculating structures made of ultra high-performance steel fiber-reinforced concrete (UHPC) in terms of strength and deformations is an important step towards the introduction of this innovative material into the practice of design and construction. This paper presents the results of finite element modeling of the operation of UHPC I-beam in the area of action of shear forces. The SMM model integrated in the OpenSees framework application is used for the walls of beams under conditions of flat stress. The authors have added new classes of materials that implement the averaged deformation laws of UHPC (with and without fiber) and the reinforcement placed in it. The calculations showed good convergence with the authors' own test results of the UHPC I-beams, as well as with the results of experiments by other researchers.

Keywords: shear strength, shear force, ultra high-performance steel fiber-reinforced concrete, I-shaped beams, OpenSees

The choice of the method of force calculation of building structures is preceded by an analysis of the static determinacy and immutability of the rod system using structural formulas, while for different types of structures - for beams, trusses, frames, arches, etc. - sources offer different formulas. It is shown that for the structural analysis of all rod systems it is sufficient to determine the degree of structure anomaly using the formula of P.L. Chebyshev. The development of the linear-monad theory of structure makes it possible to formalize the dependence of the number of rods and hinges on the number of external and internal contours in the synthesis of both normal and anomalous structures

Keywords: beam, truss, frame, arch, structure, analysis, synthesis, immutability, definability, degree of anomaly, rods, system, contour, monad, hinge

The situation of occurrence, identification and management of risks arising during the construction process is analyzed. Uncertainty of decision-making in construction projects involves the creation of methods that ensure the reliability of decisions and their effectiveness. Such a method was developed in the Russian Project Management Association. The paper provides an example of using this method on a real construction site. An analysis of risks arising during the implementation of a construction project was conducted, a risk map was created for this project and the PERT method was applied when creating a calendar plan.

Keywords: uncertainty, risk event, probability, risk, damage, danger, reliability, risk analysis, investment and construction project, PERT method

Based on the results of experimental studies of the propagation of bending waves, the ability of the developed technique to assess the strength of a brick treasure is considered. A comparative analysis of the strength of the masonry was carried out using different methods (L.I. Onishchik formula, Eurocode 6). According to the correlation dependencies between the velocity of propa-gation of elastic waves and the strength of masonry, the presented practical data made it possible to prospectively evaluate the method using bending waves in the survey of buildings and struc-tures.

Keywords: experimental studies, brickwork, elastic waves, bending wave velocity, strength

Анализируется методика определения напряженно-деформированного состояния металлических опор линий электропередач при технической экспертизе объектов электросетевого хозяйства. Даётся пример расчета с использованием автоматического программного комплекса ЛИРА. Определяется наиболее напряженные участки конструкций. Расчётным способом подтверждается гипотеза о том, что трехгранное поперечное сечение траверсы портальной промежуточной опоры ВЛ 500 кВ экономичнее (эффективней) чем четырехгранное (классическое) поперечное сечение.

Keywords: building structures, metal structures, energy facilities, stress-strain state, technical expertise

Providing the population with comfortable housing has always been a pressing issue. However, there are very few formalized criteria for this, apart from the regulation of minimum floor areas. In this context, the article deals with the problem of evaluating the efficiency of residential space design solutions in terms of their logistical comfort. For this purpose, a method is proposed that uses the apparatus of graph theory and allows to calculate the time cost of an "idle" move for a representative of a given social group in relation to the evaluated design solution. An idle move is a user's movement between characteristic functional zones of the layout. A special matrix is used to model the links between these zones, the construction of which is similar to that of the incident matrix in undirected graphs. As an example of the applicability of the proposed approach, several variants of layouts of one-room, two-room and three-room flats are considered. The comparison of the obtained results for different types of layouts, including those that existed 15-20 years ago and modern ones, indicates a tendency to increase the logistic comfort of modern layouts.

Keywords: planning solution, logistic comfort, idling, graph theory

Authors considered the thermal inertial properties of some building envelope constructions which included the changes of internal surface layer materials. Researchers described the thermal and physical characteristics of 6 building surface layer materials. It has been determinate the radiant temperature of building envelope inside surface with changes of wall construction after 225 hours cooling process and initial temperature equal to +23 оС. Authors defined the cooling time of building envelope inside surface to 0 оС at different types of surface layer materials. Numerical experiment was done with modern program complex “Stf”. Modeling process was completed in program which was realized with finite difference method and constant heat transfer coefficient. There are new experimental results which were determinate during the research and realizing the mathematical model of non-stationary element’s cooling process. Results could be interested for researchers of thermal phenomena in building envelopes and designers of microclimate engineering systems in buildings and structures.

Keywords: air temperature, radiation temperature, stationary regime, non- stationary regime, building envelope, emergency regime, thermal inertia, inside surface layer, program, building materials

The article shows the importance of analyzing the state of strength properties of old wood during restoration work and monitoring the state of the structure. In particular, the physical and mechanical properties of wood during long-term use in an aquatic environment are analyzed. Changes in the chemical composition of wood as a result of use in the water of the Gulf of Finland are determined. Using the example of logs of the crib foundation of the Kronshlot fort, it is described how a change in the chemical composition of the material affects its strength properties.

Keywords: Mechanical properties of wood, long-term strength, chemical composition of wood, water-soluble extractive substances

Slag-alkali binder (SAB) is obtained by polymerization of granulated blast-furnace slag (aluminosilicate component) ground in a ball mill with an alkali activator, resulting in an environmentally friendly hydraulic polymer binder. Slag-alkali concrete (SAB) based on SAB has become an alternative to traditional concrete based on portland cement (PTC). Reinforcement bars in combination with SAB make it possible to obtain concrete structures with high adhesion properties to reinforcement compared to concrete based on portland cement. However, due to differences in the production process of SAB, there are obvious differences in technical properties, including adhesion characteristics. However, proper standardization is needed for its production and operational testing to limit contradictory results in the laboratory and on the construction site.

Keywords: metallurgical waste, granulated slag, crushing, chemical activation, reinforcement, adhesion, strength

The stability calculation of a П-shaped hinged frame is considered. The concept of r-like frames is introduced as frames with the same ratio r of the linear stiffnesses of the transom and the strut. It is shown that the parameter vcr , which determines the critical load on the frame, is the same for r-like frames. Approximate formulas allowing to determine the critical load parameter vcr and design lengths of compressed bars with an error not exceeding 2% are obtained.

Keywords: flat frame, stability, critical force, reduced length coefficient, r-like frames, approximation, least squares method

The article is based on modelling several variants of information diagrams of a corrugated monolithic ceiling of an industrial building. The information model has been transformed into an analytical model. The comparative analysis of all calculation models was carried out visually and in numerical aspect. The efficiency of BIM-technologies in design with the application of software complexes «Renga», «CAPFIRR-3D» and «LIRA-CAD» is also considered in the calculation and construction section. The comparative analysis of three variants of the joints of the beams and the slab of the covering was carried out. The analysis of the stress-distorted state of the calculation circuit was also performed.

Keywords: ribbed slab, industrial building, design of buildings and structures, BIM-technologies, calculation scheme, information model, rigid insert, stress-strain state, finite element method

The article discusses issues of improving the quality and safety of pedestrian and vehicle traffic in underground linear structures. The main parameters of traffic safety in tunnel-type transport structures are considered. The scope of application of luminescent and retroreflective materials in the construction and operation of concrete and asphalt concrete pavements has been determined. Recommendations are given for the use of special luminous materials in construction practice.

Keywords: concrete, asphalt concrete, reflective coatings, luminescent materials, traffic safety

In this article the existing principles of application of the illusion technique in architecture are considered. The classification of objects by purpose is presented, the key features of classification groups are highlighted. Examples of already existing constructed buildings with different typology are given and analyzed. The target direction of the article is based on the creation of the concept of volume (building) with the use of optical illusions to form a complex solution to clarify the overall concept of the object and achieve the effect of paradox in the viewer. The article also describes in detail the art-architectural and constructive solutions of the proposed concept with the definition of the exact location of the building in relation to the view and approach to it.

Keywords: Illusion, architectural volume, complex solution, paradox, dematerialization, visual perception, structural element, mirrored surface, hovering effect, tilt angle, master plan organization

The article describes the main problems associated with the principles of calculation and design of building structures of buildings and structures in seismically active areas in accordance with the provisions of the regulatory document SP 14.13330.2018. The difficulties that may arise when using foreign regulatory requirements in terms of design and calculation are noted. The calculation of a flat steel multi-story frame for the main and special combination of loads and impacts is considered. The frame calculation for a special combination is performed according to SP 14.13330.2018 with and without taking into account the additional requirements of foreign design standards ASCE / SEI 7-22, ANSI / AISC 341-22. The requirements of foreign standards were not taken into account in full, but only in terms of increasing the reliability of the structure, for certain positions. The change in the parameter of the frame metal consumption for various calculation options is analyzed. Conclusions are formulated and recommendations are given on how to reduce the metal consumption when calculating for seismic impact, taking into account the increase in the reliability of building structures.

Keywords: finite-element schemes, columns, crossbars, seismic action, steel frames, flat frames, design, limit states, material consumption, optimization, reliability, special combinations, combination factors

The article provides an analysis of the state of the rationing issue in terms of performing the calculation justification and design of reinforcement of reinforced concrete structures using external reinforcement systems based on carbon fibers. The normative documents of the Russian Federation and foreign ones are considered, the analysis of the use of external reinforcement based on composite materials for structures of various types of work is carried out, the disadvantages of existing calculation and design methods are highlighted. In conclusion, recommendations are given on the appropriate improvement of calculation and design methods.

Keywords: external reinforcement, carbon fiber, reinforcement, restoration

The article presents the results of the laboratory test and finite element modeling of the facade basket design for the outdoor unit of the split system. A comparative analysis of the obtained data is performed. During the modeling, the main possible design situations were taken into account and the perilous zones were determined, in which destruction is expected. To confirm the obtained design values, a full-scale test was carried out, in which wind pressure was modeled using two horizontally applied loads. Based on the test results, it was determined that the modeling method used corresponds to reality, and the nature of destruction and maximum permissible loads were also established. Based on this, a conclusion was made about the suitability of using the facade basket design option considered in the article for the specified operating conditions.

Keywords: finite element model, testing, load-bearing capacity, reliability, deformability, air conditioner basket, bracket, destruction

The article examines the two-dimensional flow around rectangular cylinders with an aspect ratio from 0.1 to 2.0 using the k-Realizable turbulence model with a Reynolds number of 2×E5. Numerical calculations in the ANSYS Fluent program have obtained changes in the coefficients of drag, transverse force and the Struhal number depending on the size of the prism section. The calculations were carried out at the intensity of turbulence of the incoming flow 2% and 4%. According to the results of calculations, it was found that with turbulence 4%, there is a good coincidence of the total aerodynamic characteristics with the available experimental data.

Keywords: flow around a rectangular cylinder, k-e Realizable turbulence model, aerodynamic characteristics of a rectangular cylinder

The architecture of multifunctional residential complexes (MFRC) is considered in the aspect of “resistance” to external factors and influences. There are four levels of formation of the MFRK: the level of urban planning structure; level of volumetric-spatial organization; level of functional and architectural planning structure; the level of compositional organization and search for the expressive appearance of the MFRK. At each of the identified levels, the “target” indicators of “sustainable architecture” are achieved. The process of forming the MFRC is considered as a sequence of combinatorial search stages and procedures based on modeling the geometric parameters of the visual model of the MFRC in order to get as close as possible to the “stability indicator”. Four methods of combinatorial search modeling are proposed: the method of “overlaying” planning frames; method of “tracing” the formative contour; method of “collaging” functional planning elements; a method of combining “regular grids” in the public, business and residential parts of the MFRK. To intensify combinatorial search procedures, it is proposed to use digital design technologies.

Keywords: university complex, transit urban spaces, scenario approach, functional-thematic zones, architectural and environmental modules

The paper presents the results of the survey of consoles of precast reinforced concrete columns of an industrial building under construction. The consequences arising from errors during the manufacture of columns, as well as the method of calculating the console are described. The survey was carried out in order to detect the position of the reinforcement in the consoles of reinforced concrete columns. When performing a survey of the technical condition, the following tasks were set: to determine the actual condition of the supporting structures, their mating nodes at the time of the survey, to establish the actual reinforcement of the structures, to give recommendations for the restoration (strengthening) of the bearing capacity of the column consoles.

Keywords: inspection, load-bearing capacity, concrete, column, reinforcement, strengthening

The paper presents the results of the survey of the reinforced concrete monolithic foundation of a ball mill with central unloading. The consequences of errors made during the construction of the foundation of machines with dynamic loads, as well as the foundation monitoring methodology, are described. The survey was carried out due to an increase in the vibration level of the equipment installed on the foundation and the detection of foundation defects in the form of cracks and chips in concrete. When performing the technical condition survey, the following tasks were set: to determine the actual condition of the supporting structure at the time of the survey, to establish the physical and mechanical characteristics of the materials of the structure, to indicate the characteristics and dimensions of damage sufficient to determine the volume of repair and restoration work, to develop recommendations for further safe operation of the structure.

Keywords: inspection, bearing capacity, foundation, dynamic load, concrete, reinforcement, strengthening