Introduction. The relevance of the study is driven by the strategic objective of ensuring the urban planning safety of small towns in Russia. The pursuit of urban planning safety is achieved through the implementation of a policy of managed shrinkage, which is intended to shape a compact urban form. The objective of compactness is achieved by densifying the built-up area, increasing infrastructure provision, and attaining 15-minute accessibility to key social facilities. The scientific problem that is the focus of this study is the limited exploration of the urban-planning aspects of compact-city formation. The objective of this study is to establish principles for the development of compact cities under a managed-shrinkage policy, with a view to ensuring the safety of urban planning. The objectives are: to analyze existing practice; to define sustainability aspects of compact cities under managed shrinkage; to develop a conceptual and theoretical model; to assess spatial compactness in three case cities; and to formulate principles for compact-city formation.

Materials and methods. The development of the research object, conceptual and theoretical model, and study design was underpinned by a systems approach. The collection and processing of data was facilitated by the utilization of spatial and geoinformation modelling techniques.

Results. The study encompassed three small Russian towns — Istra, Gusev, and Nevyansk. The urban fabric was analyzed, and 15-minute accessibility for multiple transport modes was evaluated using isochrone-based analysis. Spatial connectivity was also verified. The findings of the study resulted in the formulation of principles for the establishment of a compact territorial–spatial structure, with the objective of ensuring the safety of urban planning.

Conclusions. The assurance of urban planning safety in Russia’s small towns represents a nationwide undertaking in urban development. The implementation of compact-city formation under a managed-shrinkage policy has the potential to contribute to the enhancement of the Urban Environment Quality Index. The study proposes and substantiates four principles of compactness: spatial connectivity; ensured accessibility of urban areas; prioritization of the street-and-road network by mobility type and context-sensitive design of street-and-road segments. The implementation of these measures will contribute to the scientific and
methodological framework for developing small towns and support progress towards their sustainable development goals.

Introduction. Historically, the cities of Syria were formed according to the model of spontaneous feudal buildings, traditional for Central Asia and the Middle East. Its archaism hinders the modernization of life according to modern standards. The destruction of large cities creates a reason for renovation of buildings in forms that combine architectural traditions and modernity, which forms the basis of the concept of renovation adopted in the article. The second concept is represented by the hypothesis of the redevelopment of the desert around Palmyra, using irrigation methods and creating conditions for agricultural settlements. Both concepts are based on a single typology of spatial units of urban development organization.

Materials and methods. Post-war reconstruction programmes are based on an analysis of the existing synthesis of oriental “carpet” buildings and the so-called “European city” with attempts to average spatial forms that meet both climatic parameters and modern standards of comfort. The study of the world’s experience in rebuilding destroyed cities determines the range of measures and techniques for building reconstruction, its typological and functional renewal. At the same time, specific measures have been investigated to return Palmyra to the importance of the economic and cultural center of the country.

Results. The development and application in the practice of restoring the planning unit of urban development (Navahi — equivalent to the mahalla of Central Asian cities) will allow in a short time to restore urban development with a unified collection of standard projects, create a full-fledged habitat for rural regions based on irrigation. Creating real prerequisites for the restoration of Palmyra.

Conclusions. Despite the difficult and uncertain situation in the country, the process of rebuilding what was destroyed should begin today, even if it is based on a preliminary model for solving the problem of temporary resettlement with a view to subsequent adjustments.

Introduction. One of the key challenges in integrating profiled decking with roof purlins and truss systems is creating a reliable, stiff connection between them. Conventional fasteners used in practice often exhibit insufficient strength around the hole edges, limiting the decking’s contribution to the overall load-bearing system. Therefore, it is important to develop design solutions that enhance the load capacity and rigidity of the joints that attach thin-walled elements to roof purlins.

Materials and methods. This study proposes and analyzes a bolted connection reinforced with carbon-fibre composite elements. A theoretical calculation of contact stresses in the washer area was carried out, conditions leading to sheet crushing were identified, and the effectiveness of the external reinforcement was assessed. Experimentally, bolted connections in H153 profiled decking (08ps steel, 1.5 mm thick) with M12 bolts were tested both without reinforcement and with overlays of epoxy-impregnated carbon fabric.

Results. Theoretically, reinforcement with carbon fibre was shown to reduce contact stresses in the connection by increasing the equivalent stiffness of the bolted joint zone. Experimentally, the reinforced connections demonstrated up to a 40 % increase in load capacity within the elastic range compared to non-reinforced joints.

Conclusions. Applying external carbon-fibre reinforcement significantly improves the reliability and stiffness of bolted connections in thin-walled profiled decking. The proposed solution ensures the joint can withstand operational loads, prevents the onset of local failures, and enables the decking to act compositely with the roof’s primary load-bearing elements.

Introduction. A large number of natural and artificial materials exhibit various mechanical properties under compression and tension. Such materials are called bimodular. It can also be noted that materials having the same modulus of elasticity under compression and tension during testing exhibit bimodular properties during their operation in building structures.

Materials and methods. The research described in the paper is related to the construction of a family of one-parameter smooth infinitely differentiable hyperelastic potentials for incompressible bimodular materials in one-dimensional motion; the derivation of closed-form solving equations, including the equation of motion, the Hadamard compatibility equation and the energy balance equation; performing a dynamic analysis of the propagation of harmonic vibrations in a semi-infinite rod. The developed method is based on a combined mechanical and thermodynamic approach combined with an energy-saving explicit numerical Lax – Wendroff scheme.

Results. A family of one-parameter infinitely differentiable hyperelastic potentials for three-dimensional infinitesimal problems on bimodular isotropic materials is constructed, which gives a set of homogeneous approximations to the discontinuous stepwise modulus of elasticity adopted in the initial one-dimensional bimodular formulation. The introduced dependencies make it possible either to obtain analytical solutions or to derive explicit solving equations for a number of static and dynamic problems. The theorem of convergence to a discontinuous module for bimodular materials is proved.

Conclusions. Shock wave fronts that appear in one-dimensional rods made of nonlinear materials modeled by a family of smooth hyperelastic potentials clearly demonstrate that their formation is not caused by a discontinuity in the stress-strain ratio corresponding to bimodular materials. Shock wave fronts occur in materials modeled by the considered smooth hyperelastic potentials both in the case of bimodular material and any other hyperelastic material. The propagation of shock wave fronts leads to the dissipation of mechanical energy, which implies a decrease in amplitudes with distance.

Introduction. The feasibility of increasing the accuracy and generality of simplified solutions for calculating the settlement of single piles is shown. Such solutions are recommended by the building codes of the Russian Federation for assessing the design settlement of piles and are also used to determine the parameters of contact models when developing pile foundation structures. The limitations of existing methods for calculating single piles are noted.

Materials and methods. An analysis was carried out and an improvement was developed for an engineering methodology in which the settlement of a single pile is calculated using elastic dependencies, according to the data of a normative assessment of the load perceived by the friction of the soil against the lateral surface of the pile shaft, and the load transferred to the soil by the fifth pile under the working load on the pile. The ratio of these loads reflects the influence of the elastic-plastic work of the soil, in the range of the design load allowed on the pile.

Results. Based on the results of the presented studies, the field of application of the analytical calculation method based on the approximation of the pile behaviour in an elastic half-space is indicated — assessment of its initial linear resistance. Alternative engineering solutions to the problem of determining the pile settlement are considered taking into account the practical elastic-plastic work of the soil, in the range of the permissible design load on the pile. A refined solution to this problem has been developed, providing more practical results of pile settlement calculations that meet the concepts and empirical basis of the current design standards of the Russian Federation. Comparisons of the calculation results by various methods are presented. The previously developed analytical elastic and elastic-plastic engineering solutions substantiated in this paper’ describe the transformation of the initial linear resistance of the soil to its elastic-plastic resistance under the permissible design load on the pile. The combined application of these solutions ensures the development of a reliable and rational pile foundation design through calculation using a nonlinear contact model.

Conclusions. Simplified solutions for calculating the settlement of single piles are in demand in construction practice; increasing the accuracy and generality of such solutions ensures the determination of adequate parameters of contact models for developing reliable and rational designs of pile foundations. The developed engineering solution for determining pile settlement taking into account the practical elastic-plastic behaviour of the soil is advisable to use for the design assessment of pile settlement from the permissible working load on it and for determining the parameters of linear and nonlinear contact models. The adequacy of the developed solution is ensured by the use of a well-proven in geotechnical practice consideration of stress and strain concentration in soil areas adjacent to the load transfer point.

Introduction. The relevance of the study is driven by the need for an integrated approach to managing occupational safety and environmental safety at all stages of the life cycle of construction projects in dense urban environments. The aim of the work is to develop a mathematical model for selecting effective organizational and technological solutions that integrates technical, economic, environmental, and social parameters.

Materials and methods. The research is based on an improved mathematical model founded on a comprehensive criterion that includes reduced costs, the probability of life cycle events occurring, and a quantitative assessment of technogenic impact. The model is enhanced with coefficients accounting for the level of automation γ, spatial constraints ψ, and adaptability to changing conditions θ. For model validation, air quality monitoring was performed using IoT sensors on construction sites in Volgograd; the data was integrated into a BIM platform.

Results. The developed model allows for a quantitative assessment of the effectiveness of solutions through the minimization of the comprehensive criterion Kij. Testing on specific operations (earthworks and plastering) showed that the implementation of dust suppression measures (fogging systems, exhaust units) reduces the criterion value by a factor of 1.40–2.48. The discrepancy between forecasted and actual monitoring data did not exceed 15 %, confirming the model’s adequacy.

Conclusions. The proposed model is an effective tool for the adaptive management of construction projects. It ensures comprehensive risk accounting, dynamic data updates based on BIM and IoT, and adaptation to dense urban conditions. The study’s results are recommended for application to enhance environmental safety and occupational safety throughout a facility’s entire life cycle.

Introduction. The paper examines the influence of impurities on struvite crystallization during nitrogen and phosphorus extraction from highly concentrated wastewater. The practical importance of considering inhibiting and intensifying factors to increase the yield and purity of the product is shown.

Materials and methods. The reviewed publications from 2006–2025 in Russian and English, selected by searching in large bibliographic databases, are summarized. The types of wastewater and process conditions (acidity range, magnesium, ammonium, and phosphate ratio, use of seed, reactor operating modes) and the influence of inorganic and organic impurities are analyzed.

Results. The main inhibitors are: calcium (conversion of phosphorus to calcium phosphates), iron (III) (competitive precipitation of iron phosphates), heavy metals (lattice defects and growth retardation), the carbonate system and dissolved carbon dioxide (reduced magnesium availability and the proportion of phosphate ions), and high-molecular organic substances (complexation and surface passivation). Small doses of aluminum with a coagulating effect, the use of solid particles as seed and optimization of the ionic strength are described as intensifiers.

Conclusions. For sustainable struvite formation in real wastewater, pretreatment (reduction of calcium and iron, removal of heavy metals and organic impurities) and supersaturation control (acidity control, removal of carbon dioxide, and the introduction of seeding agents) are required. Considering the composition of impurities increases the degree of extraction of phosphorus and ammonium nitrogen and improves the quality of the product.

Introduction. The study puts forward a proposal to use cold accumulators for air treatment in air conditioning systems (ACS) of buildings and structures in order to reduce the load on the refrigeration machine during peak operating conditions, as well as to equalize the load on equipment. A number of sources were analyzed, confirming the relevance of the study and covering the topic under study in detail.

Materials and methods. Two schemes of a cold accumulator based on direct contact of media are proposed, and mathematical models of the crystallization and accumulation process are constructed. The operating parameters of the refrigeration machine as part of the ACS are calculated and the energy consumption of the ACS is optimized using the Lagrange multiplier method.

Results. Liquid media, primarily salt solutions and freons, were mainly considered for cold accumulation. Analysis of sources showed that cold accumulators with direct contact of media are an effective and promising technology for increasing the energy efficiency of refrigeration systems of buildings and structures. Based on this, a detailed calculation of the accumulator was carried out. A mathematical model of the solution crystallization process during ice accumulation was built and the parameters of the accumulator and refrigeration machine were calculated. Two schemes of cold accumulation technology in the refrigeration machine system of the ACS were studied — by the method of separate ice production and an ejector scheme. The obtained modeling results showed that the use of new cold accumulation technologies in ACS systems allows re-
ducing energy costs for operation by 20–30 % and reducing initial capital investments. The economic effect is achieved by reducing the load on the equipment at peak consumption values. This allows us to say that for the design stage it is possible to reduce the equipment power by selecting it based on half-peak values, with compensation using accumulation.

Conclusions. The data obtained showed that the proposed cold storage solutions have lower energy consumption compared to analogues by 20–30 %, and are also capable of increasing the efficiency of ACS.

Introduction. The motivation for this study was the change in the calculated temperature of the coldest five-day period in the Belgorod Region according to the latest reference data, which runs counter to the global trend of climate warming. A hypothesis was put forward about the possible groundlessness of the obtained reference data and an experimental verification and analysis of the obtained results were carried out. Data on the change in climatic parameters of the heating season in the Belgorod region are presented. Shortcomings in the existing methodology for calculating the provision of the coldest five-day periods were identified and ways to solve this problem were proposed.

Materials and methods. To calculate the main climate parameters of the cold period of the year, archives of data from existing meteorological stations were used. The Pandas library for data processing and analysis was used to process the data; the Matplotlib library was used for data visualization; the SciPy library was used to solve the mathematical problems presented in the work.

Results. The detailed results of the study of changes in the climatic parameters of the Belgorod region are presented. Detailed descriptive statistics are shown for each of the meteorological stations with a sufficient depth of data archive for research. The change in average annual temperatures of meteorological stations during the entire period of research is presented. Changes in the main calculated parameters of heating periods are calculated and visualized. Calculations are made to establish the temperatures of the coldest five-day period at each meteorological station in various combinations.

Conclusions. It was revealed that climate changes in the Belgorod region, according to data from all meteorological stations in the region, correspond to global climate changes. The temperature of the coldest five-day period with a provision of 0.92 specified in the latest edition of construction climatology is excessive and does not reach –24 °C under any of the justified combinations. The obtained temperatures of the coldest five-day periods of meteorological stations are lower than the established value by 1–2 °C. It is proposed to use several regional meteorological stations to calculate the coldest five-day periods. These proposals will contribute to a justified reduction in the cost of heating systems.

Introduction. The need to create a technology for the rapid installation of temporary bridges in emergency situations has led to the development of a new method of crane-free installation. The purpose of the work is to create an effective technology for the installation of a collapsible temporary large — span structure for quick installation in difficult conditions without the use of crane equipment. Scientific novelty — an innovative approach to the installation of superstructures using modular assembly is proposed. The technology is based on a combination of hydraulic jacks and a winch and is highly variable. Further development opens up new opportunities for reducing the duration of temporary road/footbridge construction in the event of unforeseen situations.

Materials and methods. Traditional installation methods were studied. The optimal design solution was selected — a cross-beam made of composite materials based on calculations performed in the SCAD programme, used as a load when calculating lifting hydraulic cylinders. A crane-free mounting technology with a lifting frame on rail rails was developed. Calculations have confirmed that this solution is technically feasible and has the necessary margin of safety, reliability and safety of operation.

Results. Temporary span structures made of composite materials with precise docking points have been created. The SCAD++ programme performs 3D modelling and load analysis. The optimal cross-beam structure was selected.
An external housing was developed for transportation and installation. The technology is adapted to work from land or water, computer control is supposed to be installed on the system for synchronicity of work, and it is suitable for urban development and emergency situations. The introduction of the technology reduces the time of installation and the cost of construction, including by saving from the non-use of heavy machinery by 15–25 %.

Conclusions. The technology of crane-free installation of bridge spans up to 50 m using hydraulic jacks and winches has been developed. The technology allows you to quickly mount structures in any conditions, including disaster recovery. The upper orthotropic coating increases the load-bearing capacity and prevents vehicles from sliding.

Introduction. Despite the large number of studies on the nature and assessment of production potential of industrial companies, a number of issues are insufficiently elaborated, especially at the level of individual industries. In addition, there is no systemic perception of production and technical potential as a basis for the functioning and competitiveness of the companies. In this regard, the aim of the paper is to identify and develop a methodology for assessing the level of production and technical potential of the building companies in the context of industry specifics.

Materials and methods. To assess the level of production and technical potential, we propose an integral indicator obtained as a result of synergy of a number of relative indicators, taking into account their weighting coefficients. The system of evaluation indicators includes known indicators (the physical depreciation coefficient of the active part of the main production assets, the share of their active part, the labor stock), as well as new introduced indicators, such as the ratio of renewal and retirement rates of fixed assets, the coefficient of progressive technologies. All weighting coefficients used at different stages of calculation are determined on the basis of data obtained through electronic survey of production managers and employees of scientific and educational sphere.

Results. An essential definition is proposed, according to which the production and technical potential of building companies is formed on the basis of the relationship between the applied technologies and the corresponding main production means. The system of indicators and the methodology of their evaluation are developed. The calculation of the level of production and technical potential of several medium and large building companies of the Voronezh region, carried out on the basis of their survey, showed that only one enterprise has a high potential.

Conclusions. The developed nomenclature of indicators and the methodology of evaluation of production and technical potential of the building companies are characterized by comprehensiveness and take into account the specifics of the industry. Approval of the research results has revealed the urgent need for modernization of production in most building companies in the Voronezh region.

Introduction. Digitalization and digital transformation are key development trends manifested by the investment and construction industry in Russia and worldwide. However, in research, digitalization and digital transformation are often considered generically in relation to all enterprises in the field, or, alternatively, one small group of enterprises is identified. The purpose of this study is to identify industry-specific characteristics of digital transformation in the field of personnel management, including shortage of qualified personnel, resistance of management and employees to changes in the process of
transition to digital technologies. The study focuses on enterprises performing different activities within the framework of investment and construction projects.

Materials and methods. The research is backed by the data collected by launching a sociological survey and an online questionnaire within the framework of a study of digitalization implemented at Russian construction enterprises. The data thus collected were statistically processed, and factor analysis was applied to find correlation between characteristics of enterprises and their main activities (functional orientation).

Results. Respondents analyzed the shortage of qualified personnel proficient in digital technologies. Integrated analysis is presented; it is also broken down by groups of enterprises clustered by functions. In the same manner, resistance to change was also analyzed; as a result, a group that is resistant to change was identified. This behaviour is typical for regular employees; however, it is also largely demonstrated by executives and mid-level managers.

Conclusions. The analysis underlies the conclusion about the need to plan and streamline processes of digitalization and digital transformation, taking into account all studied aspects and scientifically grounded proposals to reduce resistance to change in such cases. Measures taken to reduce resistance to change will reduce its negative manifestations and increase the efficiency of digitalization and digital transformation processes.

Introduction. Within the framework of the federal project “Creation of a Network of Modern Campuses” a key strategic challenge is the development of a competitive product portfolio that ensures the effective functioning of campuses at national, regional, and institutional levels. A pilot initiative on developing campus product programmes has been launched, positioning each campus component as part of an integrated product system designed to meet the needs of diverse user groups. The purpose of this study is to formulate a scientifically grounded definition of the “campus product”, drawing on the academic concept of the value chain, and to develop an approach to structuring a competitive campus product portfolio aligned with national priorities, regional socio-economic challenges, institutional strategies, market demand, and economic performance requirements.

Materials and methods. The study is based on an analysis of regulatory documents of the federal campus project and methodological guidelines for designing campus product programmes, as well as academic works on portfolio management, value creation theory, and product marketing. The methodological framework integrates structural–logical and comparative analysis, conceptual modelling, and expert-analytical factor classification. This combination allows for the formulation of principles for developing the structure of a campus product portfolio grounded in the alignment of strategic objectives, user value, resource capabilities, and economic conditions.

Results. The research introduces a process of portfolio value management that integrates the principles of project portfolio management (PPM) with those of customer relationship management (CRM). A substantiated set of factors is proposed for analytical assessment in structuring the product portfolio under conditions of achieving competitiveness. The study formulates the concept and defines the structure of a balanced product portfolio understood as an interconnected system of products jointly generating a unified consumer value that underpins competitiveness.

Conclusions. A balanced campus product portfolio is a critical determinant for achieving the intended effects of this project under conditions of competitiveness. The product portfolio becomes competitive not when it represents a collection of discrete outputs, but when it forms an integrated system in which each product comprises a set of expected user outcomes as well as the chains and mechanisms through which these outcomes are created.