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 rocks that form a natural geological reservoir for underground gas storage, during the operation of UGS, are exposed to prolonged cyclic loads caused by periodic injections and withdrawals of natural gas. At the same time, it is possible to develop and accumulate residual deformations in rocks that cause irreversible changes in the properties of rocks and this must be taken into account when designing and operating UGS.

Keywords: underground gas storage, geomechanical modeling, cavern, salt massif, deformations

the work is devoted to a comparative analysis of various calculation and mathematical models among themselves. The calculation of the frame joint of reinforced concrete structures is performed: a pylon and a cantilever beam. Three methods for performing the calculation of this joint are proposed: an analytical method, a rod FEM model and a volumetric FEM model. The analysis of the calculation results is performed: a comparison of internal forces and calculated reinforcement. The consequences of a superficial analysis of the structure and simplification of calculation models are shown using the example of damage to a real structure under the action of operational loads.

Keywords: reinforced concrete console, structure calculation, node calculation, Lira 10, Russian software, optimal design of reinforced concrete structures, reinforcement analysis

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 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 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 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 article proposes an approach to determining the level of developer brand protection, which is understood as the reputation of the developer in relation to the regional market, formed in the Internet. The level of protection of the developer's brand takes into account the Gunning Nebula Index of text reviews about the developer, the average volume of words in text reviews about the developer, the number of negative text reviews about the developer, the total number of text reviews about the developer and the degree of competitiveness of the real estate market in the region. Estimates of the level of brand protection of developers in Perm and Yekaterinburg are given and analyzed. To reduce reputational risks and increase the level of brand protection, if it is not high enough, developers are recommended to regularly collect positive customer feedback, conduct brand protection audits, collect and classify negative feedback into true and false. True negative reviews should be discussed with customers, address the cause of the negative review, and then invite customers to remove or correct the negative review. When dealing with false negative reviews, you should seek their removal or publish detailed reasoned rebuttals to them online.

Keywords: real estate developer, online reviews, Gunning Nebula Index, brand protection, degree of competitiveness in the market, reputational risk management

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

Modernization of university campuses in the context of the development of domestic higher education and science to increase the technological sovereignty of the country is one of the pressing problems of modern domestic architecture. The article examines the main factors that determine the need to modernize existing university campuses and influence its capabilities and tools. Based on the analysis of these factors, the main modern requirements for campus modernization are formulated.

Keywords: modernization, university campus, modernization factors, modernization requirements

The article analyzes the idea of architectural reserves proposed by Pskov architect and restorer Yu.P. Spegalsky in the middle of the XX century. The Pskov restorer proposed to allocate separate sections of the city center with ancient monuments on their territory as the basis for its development as an open-air museum. The plan was not implemented, but later this theory was used as the basis for successfully implemented modern restoration and architectural projects aimed at developing the urban environment of Pskov. The options for continuing the development of the idea in the near future are considered on the example of a complex formed by ancient defensive structures and a monument of constructivist architecture.

Keywords: Y.P. Spegalsky, architecture of ancient Pskov, creativity of A.A. Olya, restoration in Pskov, Mstislavskaya Tower.

The article discusses the features and prospects of implementing distributed management of critical urban infrastructure facilities based on the principles of autonomy. Based on the analysis, the main technologies, directions of development and features of energy transfer in an urban environment are highlighted, contributing to the introduction of distributed management of urban infrastructure facilities. The study focuses on the analysis of the distributed structure of integrated security of critical urban infrastructure facilities and the development of general principles of distributed management of critical infrastructure facilities using the «Autonomous Building» technology. t is shown that the reliable and safe functioning of critical infrastructure facilities in the city is ensured through the synthesis of special technical systems for complex protection of the facility from major security threats based on the combined use of elements of life support and safety systems. At the same time, technical life support systems for autonomous objects of critical infrastructure of the city are built on the basis of the combined use of autonomous energy sources, including non-renewable energy sources, on the principles of joint operation of electric and static power converters, storage, frequency regulation and energy conversion, and technical safety systems of autonomous objects are built using combined optical and electronic means event detection and recognition with the ability to control the full spectrum of electromagnetic radiation.

Keywords: distributed management, technology, energy, energy transfer, urban infrastructure, critical facility, electrification, decentralization, automation, autonomy

The use of a solid analog and the involvement of an appropriate theory of stability made it possible to perform mathematical modeling and determine the parameters of the critical state of cylindrical mesh shells depending on the geometric characteristics and the number of half-waves of the shape of the loss of stability. The values of the critical load of cylindrical mesh shells are determined taking into account geometric and force factors. According to the results of calculations, the patterns of changes in the number of half-waves of the form of loss of stability and obtaining the minimum value of the critical load under the condition of maximum approximation of flexural and membrane stiffness are revealed and analyzed. A numerical example is shown in which the values of critical load and stiffness are determined, taking into account possible forms of loss of stability. The patterns of changes in these indicators for a given number of half-waves are established and analyzed.

Keywords: cylindrical mesh shells, mathematical modeling, critical load, stability, stiffness, number of half-waves