A two-level hierarchically organized model of managing the interaction of the director with the personnel in a company related to the development of projects in the construction sector is presented. The director acts as the leader, and the company's employees act as followers. Both management entities strive to maximize their target functions, reflecting their income and expenses. The study of the model was conducted taking into account its hierarchical structure. An algorithm for constructing a Stackelberg solution under inducement has been developed. A numerical study of the model has been conducted using the scenario method by partially enumerating the areas of admissible controls of subjects with a certain step. When conducting simulation experiments, all input parameters of the model varied in a fairly wide range. The results of the simulation experiments have been analyzed, and some patterns of system development have been identified.

Keywords: hierarchy, incentive, control system, solution algorithm, Stackelberg equilibrium, leader, follower, imitation, experiment, investment project

The aim of the study is to analyze modern models and algorithms for managing fire and rescue units during rescue of people in different types of public buildings. Research methods: general scientific methods (analysis and synthesis of information, comparison). The article provides a literature review of current methods and algorithms for managing fire and rescue units during rescue of people. Based on previous studies, three main approaches are identified: approaches based on technical superiority; approaches based on mathematical modeling; approaches based on taking into account the individual characteristics of the places where fire and rescue operations are carried out. The advantages and disadvantages of each approach are highlighted in terms of the effectiveness of their use in rescuing people in public buildings. When analyzing previous approaches, it is concluded that at the moment there is no methodology for substantiating the tactical capabilities of gas and smoke protection service units during fire and rescue operations depending on the technical characteristics of the premises and the number of people. The combination of mathematical modeling and consideration of individual characteristics of public buildings seems to be the most effective method of managing fire and rescue units. The study concludes that it is necessary to create an algorithm for the movement of gas and smoke protection service units that will take into account the characteristics of buildings, combustion products and the time of rescuing people. The scientific novelty of the study is due to the following elements: a systematization is proposed, and an assessment of the advantages and disadvantages of models and algorithms for managing fire and rescue services is performed; a scheme of measures for managing fire and rescue units is proposed, which takes into account the functional tasks of the fire and rescue garrison, guard service and work with the population. The scheme for managing fire and rescue units assumes both work with the entire fire and rescue garrison and with individual guard services of the fire protection service, with the population and the administration of public buildings. The proposed scheme complements the existing theoretical knowledge about the organization of the work of fire and rescue units and the management of their work when rescuing people in different types of public buildings.

Keywords: fire and rescue unit, public building, gas and smoke protection service, fire safety, method, model, algorithm

The article examines the key climatic and operational factors that determine the duration of safe operation of ice winter shelters in the northern regions of Russia. Based on the analysis of the temperature regime, precipitation and dynamic loads from transport, patterns of changes in the strength and deformation of the ice cover have been identified. Practical recommendations on monitoring, ice reinforcement and load management have been developed to extend the service life of crossings and minimize risks.

Keywords: regime, dynamic loads, snow cover, hydrological factors, crossing safety, ice monitoring

The article shows the possibility of obtaining an epoxy-containing adhesive composition using fibrous magnesium hydrosilicate of the composition Mg3Si2O5(OH)4 as a reinforcing filler. The fibrous filler is selected as a reinforcing component to impart adhesive strength to the adhesive joint between the glued surfaces of a wooden beam.Higher values ​​of the adhesive joint strength limit were obtained for the epoxy-containing composition using Mg3Si2O5(OH)4 fibers.

Keywords: adhesive composition, composition, epoxy resin, polyethylenepolyamine, polyethylenesiloxane, polyvinyl acetate, Kleiberit, water resistance, saturation, load, tensile strength, testing, properties

The results of studies of the strength properties of plaster solutions with vermiculite on a mixed binder using a multifunctional additive D-5 are presented. A slight acceleration of the setting time of solutions with a multifunctional additive D-5 was found, while the bending and compressive strengths of the solutions did not change significantly after 2 hours and 28 days. Replacing part of the expanded vermiculite fraction 0 – 0.315 mm with volcanic pumice fraction 0 – 0.315 mm in the construction mortar allows to significantly increase their strength characteristics and reduce the cost without a noticeable increase in density. Expressions of the dependence of the compressive strength of the mortars on the calculated total porosity are obtained.

Keywords: construction gypsum, Portland cement, volcanic pumice, expanded vermiculite, D-5 multifunctional additive, plaster composites, compressive and bending strength

Adhesive joints of reinforcing rods and wood are the weakest point in reinforced wooden structures, since they have low shear resistance of the reinforcing rod and contribute to the development of plastic deformations of wooden elements. To achieve elastic operation and increase adhesion to the rods, a reinforced adhesive compound with the inclusion of quartz sand is used. This article examines the operation of a reinforced adhesive joint with various types of core fittings – steel periodic profile, smooth steel and fiberglass. The work of the adhesive joint in solid and glued wood was also recognized as an important factor for the operation of the reinforced adhesive composition. Experimental studies are confirmed by graphs and tables of numerical results, which allows us to establish the reliability of the results obtained and conclude that it is necessary to improve certain methods of manufacturing reinforced wooden structures.

Keywords: rebar, reinforcing bar, reinforced wooden structure, pulling out, wooden structure, wood, glue, adhesive joint, strength, epoxy resin

Fiberglass core reinforcement could find its application in wooden structures due to a number of specific practical advantages not inherent in steel rods or other types of reinforcement. However, due to the weak adhesive properties of the surface of fiberglass rods, their full-fledged joint work with wood as a single body is not observed. The study suggests some ways to increase the strength of the adhesive joint of fiberglass reinforcement and wood, such as applying quartz sand to the surface of the rods, grinding the surface of the rods, as well as adding sand-resin casting molds to the adhesive composition. Tests of each of these methods were carried out and the results obtained were compared with the initial model of the adhesive joint, as well as with the calculated model of the adhesive joint in order to determine the most effective method.

Keywords: adhesion, reinforcing rod, pulling out, wood, adhesive joint, adhesive composition, bearing capacity, strength, fiberglass rod, epoxy glue

The paper investigates the formation and propagation of flexural cracks in beams made of ultra-high performance steel fiber reinforced concrete (UHPFRC). A comprehensive series of laboratory tests was carried out on seventeen beams of rectangular and T-shaped cross-sections, varying in longitudinal reinforcement ratios, fiber volume contents, and fiber types (straight and wave-shaped). The results demonstrate that the inclusion of steel fibers significantly enhances the crack resistance of the beams, promotes a more uniform crack distribution, and improves their load-bearing capacity. In under-reinforced UHPFRC beams, failure typically occurs due to fiber pull-out localized within one or more dominant cracks. Prior to the onset of deformation localization in the tensile zone – which coincides with the yielding of the longitudinal reinforcement – the crack widths in fiber-reinforced specimens remain below 0.25 mm. This behavior ensures that even under service-level loads (65–70% of ultimate), the crack openings stay within the allowable design limits (0.3–0.4 mm). The experimental findings contribute to a better understanding of the cracking mechanisms in UHPFRC beams and provide a valuable foundation for refining numerical models and optimizing design approaches for flexural members made of advanced high-performance cementitious composites.

Keywords: ultra-high performance concrete, beams, bending moment, steel fibers, flexural cracks

This paper shows that creatively adapting traditional Arab architectural elements—courtyards, mashrabiya screens, wind towers, and geometric ornament—enhances psychological comfort and sustainability in Gulf and North African spaces. Field data and case studies (Msheireb Downtown Doha, Louvre Abu Dhabi) reveal significant microclimate improvements: lower courtyard temperatures, reduced energy use, increased daylight uniformity, and lower stress levels. Adaptive, heritage-inspired façades and water features further support well-being and cultural identity. The findings confirm that integrating Arab architectural heritage with modern technology creates thermally stable, visually comfortable, and culturally meaningful environments that promote user well-being and reduce stress.

Keywords: courtyard, mashrabiya, barjeel, microclimate, design, interior, comfort, sustainability, ornament, lighting, bioadaptation, arab architecture

Cities prone to natural disasters face the problem of accumulating large volumes of construction waste, which is heavy and poses a source of environmental pollution and a risk to human health. This is especially true for countries in the Middle East, such as Iraq and Syria, which have suffered heavy damage as a result of conflicts and natural disasters. The presence of this waste affects the emergency response process, including the access of emergency services to the affected area and the inability to search for and save lives, and poor management of this waste leads to a negative impact on the cost and time of the recovery process. On the other hand, this waste also offers new opportunities: it can contain valuable materials such as concrete and steel, which can be either a source of income or a source of reconstruction materials, and reduce the consumption of natural resources through reuse and recycling. The aim of this study is to analyze the reconstruction process, including construction waste management, and identify the problems and obstacles that prevent local authorities from effectively implementing their reconstruction plans, as well as to present solutions to combat the huge amount of construction waste that has accumulated over the years.

Keywords: Inspection of structural elements, reinforced concrete, defects of monolithic structures, cracks, reinforcement corrosion, repair, concrete quality, cold joint, monolithic construction, concrete surface quality

Abstract: During the colonial period, the urban development policy of Guangzhou changed dramatically. These changes were the result of the collision and interaction of social, economic, cultural and other factors. This article examines the features of Guangzhou's urban development policy during the colonial period. By identifying and analyzing the features of Guangzhou's urban planning at different times during the colonial period, its changing urban development characteristics are explored. Knowledge of the spatial characteristics of Guangzhou's architectural environment during the colonial period provides a basis for future development of the foundations for the preservation and sustainable development of modern Guangzhou and other cities in China.

Keywords: Guangzhou, colonial period, opium wars, urban development policy, features of urban planning

The use of wooden elements to distribute loads from overlying structures to artificial and natural foundations has been known since ancient times. The most striking example known from ancient Greek epics is the description of the structure of the foundation of the Temple of Artemis in Ephesus (construction began around 550 BC). One of the seven wonders of the world was built in a seismic zone, but in a swampy part to minimize impacts. In those ancient times, the architects Chersiphron and Metagenom decided to lay burnt oak trunks in the foundation to evenly distribute loads on the foundation and reduce the settlement of the cyclopean structure by the standards of that time. Similar solutions were used by the architects of the Trans-Urals (Arkaim and settlements in the area of ​​the Karagayly-Ayat River), the ancient Roman port of Londinium, as well as the Neolithic dwellings in Lac de Chalen. The results of the conducted research show the technical regularities of the device of wooden grillages, ridge and sleeper structural elements in the foundation of objects of historical and architectural heritage in the architectural and construction art from ancient times to the present day. The work presents the results of the natura research, which showed the possibility of continuing the operation of buildings and structures using the specified structures.

Keywords: objects of historical and architectural heritage, dispersed environment, soil massif, artificial foundations, wooden piles, sleepers, crib foundation structures, loss of wood

The article presents a comparative analysis of the results of verification calculations of a monolithic reinforced concrete floor slab and full-scale tests, and also formulates the main factors affecting the accuracy of determining the bearing capacity of monolithic reinforced concrete structures when performing verification calculations. In accordance with regulatory documentation, the bearing capacity of building structures is determined by performing verification calculations according to current design standards and conducting full-scale tests (if necessary) to confirm the bearing capacity established by the calculations. In modern practice of technical inspection, full-scale tests are extremely rare due to their high labor intensity and the complexity of interpreting the results. However, it is full-scale tests that allow the most accurate determination of the bearing capacity of a structure. This makes it possible to correctly assess the technical condition, optimize the development of strengthening projects due to a reasonable choice of method, accurate calculation of the required volumes of work and, as a result, minimize material costs.

Keywords: bearing capacity, full-scale tests, verification calculation, reinforced concrete, floor, deflection, limit state groups, technical inspection

The purpose of this study is to develop a new approach to determining the causes of deformation cracks in brick walls and light concrete blocks, which will increase the accuracy of expert research in case of disputes. In the process of theoretical research, methods of analysis and the results of field observations were used. The results of this study include a proposal to use the concept of "damage formation mechanism", which represents the relationship between the damaging factor as a consequence and the cause of its occurrence, which preceded the consequence. The classification of deformation cracks has been updated. The results of the study are of practical importance for specialists in the field of inspection of buildings and structures to determine the cause-effect relationship of the formation of deformation cracks. The expanded classification of deformation cracks has theoretical significance, since it complements the existing concepts of damage.

Keywords: cracks, deformation cracks, types of cracks, classification of cracks, causal relationship, damaging factor, mechanism of damage formation

The article presents an analysis of methods for strengthening reinforced concrete columns without changing the original design scheme. The calculation of reinforcement with a metal collar, a reinforced concrete collar, using prestressed struts and reinforcement with composite materials under central and eccentric compression is performed. A comparative analysis of the technical indicators of the considered reinforcement methods is made. A strategy for selecting a method for strengthening reinforced concrete columns is formed. An analysis of the optimal areas of application of various methods for strengthening reinforced concrete columns shows that the choice of a specific technology should be determined by the nature of their stress state depending on the magnitude of the eccentricity of load application. This study confirms that there is no universal "best" method for strengthening reinforced concrete columns; each of the considered methods has its own advantages and disadvantages. The results allow choosing optimal solutions based on the criteria of efficiency, reliability and cost-effectiveness.

Keywords: columns, reinforced concrete, steel, reinforcement, frame, carbon fiber, comparison, optimal method

The article presents a study of chronic phytotoxicity in the area of influence of three small boiler houses, 2 of them run on coal, one on fuel oil. As a result of the research, it was revealed that both selected crops have growth inhibition. At the same time, oats show greater resistance to contamination than clover. At the same time, the root system is less susceptible to the inhibitory effect. The greatest negative impact is observed in the area of the boiler house running on fuel oil.

Keywords: small boiler houses, phytotoxicity, biotesting, negative impact, soil, oats, clover

The article presents the results of laboratory testing of a precast lintel made of D600 aerated concrete blocks fastened together using assembly adhesive for laying aerated concrete blocks and three reinforcing bars, two bars in the lower zone with a diameter of 20 mm A400 and one bar in the upper zone with a diameter of 16 mm A400. When testing the beam lintel, 3 loading schemes were assembled, each of which was a beam hinged on concrete supports. The obtained data were analyzed. Based on the test results, destructive loads, the nature of destruction were determined and the resulting deformations were assessed. The nature of destruction is similar to that of reinforced concrete beam structures with insufficient transverse reinforcement; destruction in all tested prototypes occurs in the support zone along inclined sections. The bearing capacity of aerated concrete lintels made of piece material is sufficient for use in construction practice.

Keywords: testing, bearing capacity, reliability, deformability, gas blocks, lintels, destruction

The article examines the evolution of residential development in coastal cities from the 18th century to the present. The concept of a coastal city is understood as a settlement whose living environment is interconnected with the coastline of the sea or bay, which imposes special requirements on the strength of foundations, waterproofing and anticorrosive properties of materials. The author shows why residential buildings require close attention: they experience prolonged climatic effects of high humidity, salt spray and wind erosion, and social factors such as tourist demand and the value of sea panoramas affect the density and typology of buildings. The paper identifies the key stages of architectural development: from wooden log houses and apartment buildings of the XVIII–XIX centuries to reinforced concrete structures and CLT panels of the XXI century, complemented by modern methods of moisture protection and digital modeling (BIM). Based on a comparative analysis of the loci, recommendations are given on how to combine the preservation of historical appearance and the introduction of sustainable development technologies, including polymer composite coatings, green roofs and multi-level embankments.

Keywords: coastal city, residential building, historical development, environmental factor, social factor, sustainable development, waterproofing, corrosion resistance, information modeling, polymer composite coating, green roof, bulk area, marine erosion

A brief list of problems in the operational reliability of multilayer energy-saving walls is given, and the thesis is formulated that single-layer or equal-permeability multilayer walls may have better operational properties. Information about the equipment and technology for producing foam concrete mixtures using a one-stage method is provided. It is shown that the introduction of a fibrous filler instead of some of the sand significantly accelerates the phase transition of the mixtures from a viscous state to an elastic state and has a positive effect on the operational properties of the hardened foam concrete. The list of the material's investigated performance properties includes experimentally obtained indicators of sorption properties, equilibrium moisture content, thermal conductivity, and frost resistance of thermal insulation and structural-thermal insulation foam concrete containing different amounts of fibers of different lengths.

Keywords: foam concrete mixture, foam concrete, plastic strength, fiber, sorption properties, equilibrium moisture content, thermal conductivity, frost resistance

The article contains the results of stress analysis in dangerous sections of a single-span steel box beam made of two channels, strengthened with two metal strips welded at the top and bottom between the channels, with different geometric characteristics of the strengthened elements. The results of a numerical experiment of strengthened beams are presented. According to the results of the numerical experiment, it was found that equalization of stresses in dangerous sections allows to reduce the material consumption of the structure in comparison with beams selected according to the assortment for the required moment of resistance.

Keywords: steel beam, load-bearing capacity, stresses, displacements, finite element method, structural strengthening

The article explores the application of a systems approach and machine learning methods to forecast psychoemotional states based on digital activity in social networks. The study addresses the urgent need to assess the psychological impact of increasing user engagement with digital platforms by using quantitative and algorithmic tools instead of subjective expert assessment. The main objective of the research is to identify patterns in the relationship between time spent on social networks and self-reported indicators of mental well-being, including symptoms related to ADHD, anxiety, self-esteem, and depression. Data was collected through an anonymous survey administered via the LMS platform of SUAI. The sample included 473 participants, with 75% under the age of 35. Preprocessing steps involved cleaning outliers, imputing missing values, and formatting the data for analysis. Correlation matrices and heatmaps were created, followed by clustering using the k-means method. A stacked meta-model based on logistic regression and Gaussian Naive Bayes with a random forest as the final estimator was used for classification. The study revealed distinct user groups with varying levels of vulnerability to the influence of social media. The results can be used to develop intelligent systems for monitoring mental health risks and delivering personalized digital recommendations. The article is relevant to researchers in system analysis and applied machine learning.

Keywords: system analysis, digital activity, social networks, machine learning, clustering, correlation analysis, digital addiction, psycho-emotional state, information mining

The application of electric energy storage systems in the electric power industry of the Russian Federation is considered using the example of the Irkutsk Region and the Zabaikalsky Krai. Statistical data are provided, and an analysis is conducted for the specified objects of the electric power complex. The results of calculating the economic efficiency of implementing energy storage systems are presented.

Keywords: еlectric power grids, renewable energy sources, energy storage systems, power supply

The article provides a brief analysis of obtaining data using remote sensing of the Earth and ground-based instruments to solve the problem of optimizing the production of crop products on heterogeneous agricultural land. The article proposes models for optimizing the production of crop products under average conditions and taking into account adverse extreme events. The developed models of parametric and stochastic programming meet the requirements of modern information support for agricultural producers.

Keywords: monitoring, data, optimization, deterministic model, multi-level parametric model, stochastic model, crop production