When industrial local exhaust ventilation is operating, a dusty air flow is transported through air ducts from dust-producing equipment. Its characteristics such as the trajectories of dust particles, the resistance of straight sections and shaped elements, depend in a complex way on the parameters of the discrete phase and therefore have not been studied insufficiently. Modern software packages offer various models and algorithms for calculating such flows.The aim of the work is to validate a computer model of monodisperse dust-air flow in a straight channel. For this purpose the tasks are solved - flow modeling for different particle size, density and relative concentration; calculations are carried out with recommended settings of discrete phase and a large number of turbulence and near-wall simulation models; the influence of settings on frictional resistance and particle trajectories is determined. Results. Based on the numerically obtained pressure fields, the friction drag coefficients were determined and compared with the known data for the flow of clean and dusty air. It was shown that the “standard k-e” turbulence model and enhanced wall treatments lead to the closest known value of the friction drag coefficient for dust-free air. When modeling the flow of dusty air, a large number of models were compared with different combinations of discrete phase parameters, and it was shown that there is no regularity in the drag coefficient from them, nor is there any convergence with known data. At the same time, the behavior of particle trajectories is physically reasonably depends on their density—particles with a density of 1400 kg/m3 settle significantly earlier than particles with a density of 700 kg/m3. Conclusions.The use of commonly recommended settings leads to adequate modeling of particle behavior - trajectories, deposition, which is useful for studying flows in industrial ventilation devices. But for proper modeling of frictional resistance in the channel, further research and use of more finely set models of the discrete phase and its interaction with the carrier medium are necessary.

Indoor ice rinks and arenas are among the most energy-intensive types of public facilities, which is associated with the need to ensure characteristic microclimatic and technological conditions indoors. Existing calculation methods often do not meet modern requirements for accuracy and automation as a tool for solving optimization problems in the design, construction and operation of energy-consuming systems. The purpose of the work is to study the characteristic features of heat and mass transfer processes of ventilation of indoor ice rinks with possible phase transformations of water in the room for the subsequent selection of rational technical solutions and modes of operation of ventilation systems based on mathematical modeling. The objectives of the study are to develop and verify a model of heat and mass transfer processes of ventilation in an indoor ice rink, capable of taking into account the phase transformations of water in moist air and on construction and technological surfaces. Results. A thermographic examination of the internal surfaces of the existing indoor ice rink was carried out to identify characteristic thermal zones in the room. The distribution of air temperature and humidity over the height of the ice field zone was obtained by sampling using a measuring tripod with thermohygrometers. The model of heat and mass transfer processes in an indoor skating rink has been developed and verified. Conclusions. It is revealed that the circulation in the central part of the room has a closed character, and is provided due to the formed difference in the density of the internal air, accompanied by the ejecting effect of supply jets. The presence of temperature and humidity gradients of indoor air characteristic of indoor ice rinks can be used to regulate the thermodynamic parameters of the supply air during its treatment in the ventilation system.

The main challenge in absorption refrigerating machines used for cooling in air conditioning systems for large public and industrial buildings is heat loss within their components, which reduces their thermal performance. While the relationship between thermal characteristics and the circuit design of various machine types is well understood, the impact of exergy losses in circuit elements has not been sufficiently studied. The purpose of the work is to provide quantitative data for an informed selection among different types of absorption refrigerating machines by conducting a comparative analysis of their exergetic efficiency. The objectives of the study include analyzing the thermal and exergetic characteristics of both single-stage and two-stage machines (temperature conditions, heat flows, cooling efficiency), as well as calculating total exergy losses, determining the elements of machines in which the greatest amount of exergy is lost, and making comparisons in order to select the optimal scheme based on the criterion of energy efficiency. Results. The results showed that the optimum temperature for the single-stage machine was 85 °C, and its coefficient of performance (COP) of 0.87, and a heat flow of 411.4 kW. In contrast, the two-stage machine at 140C achieved a COP of 1.522, representing a 42.9% improvement, while the heat flow decreased by 36.5% to 261.4 kW. Additionally, the two-stage machine experienced maximum exergy losses in the generator (34.7 kW) and condenser (36.4 kW), whereas the single-stage machine showed in the condenser (42.7 kW) and absorber (14.8 kW). In this case, the percentage increase in total exergy losses in the two-stage and single-stage systems are converging, and the maximum total exergy losses in the single-stage system at a temperature of 100 °C amounted to 88.7 kW, while in the two-stage system it was 56.2 kW at a temperature of 150 C, which indicates a decrease of 36.7% compared to the single-stage system. Conclusions. The results of the study show that a two-stage absorption refrigeration machine demonstrates higher energy efficiency compared to a single-stage one. This is important for the construction industry, as choosing more energy-efficient equipment reduces energy consumption in buildings and optimizes air conditioning and refrigeration systems, as well as promotes the use of renewable energy sources and reduces the carbon footprint of facilities under construction.

Water heating systems based on capillary tubes are a promising direction for research. Such systems have a number of advantages over radiator heating. However, at the moment they are not widely used. The purpose of this work is to create a model of a wall block with capillary tubes and study the parameters of its operation. The objectives of the study are: to study the uniformity of heating of the surface of a wall block using the proposed design of a capillary tube system, to study the difference in temperatures of the coolant at the inlet and outlet of the system, to study pressure losses in the studied block. Results. A fundamental design option for a wall block with capillary tubes is proposed. A model of a wall block with capillary tubes was developed, its operating parameters were studied, graphs of changes in the temperature of the coolant when passing through the capillary tube system and a pressure graph were obtained. Conclusions. The significance of the results obtained is that due to the selected design of the capillary tube system, it was possible to achieve pressure loss indicators in the system comparable to traditional water heating systems. Moreover, the uniformity of heat distribution in the heated room when using the developed design is significantly higher than when using radiators as heating devices to the greater surface area of heat exchange.

The presence of sharp edges and uneven velocity distribution in the elements of ventilation systems leads to flow separation, the occurrence of vortex zones, which, in turn, leads to a decrease in the efficiency of ventilation systems. One of the options for equalizing the flow is the installation of grilles with lamellas, guide vanes. The aim of the study is to identify the dependence of the air flow characteristics in the exhaust duct on the distance between the elements of the “grill-elbow” unit. To achieve this goal, the following problems are solved: numerical study of the flow in the exhaust duct with a “grill-elbow” unit; determination of the dependencies of the sizes of vortex zones, local drag coefficients on the distance between the elements of the unit; comparison of the obtained results with known data. Results: the flow streamlines, the dependencies of the local drag coefficient of the unit and the effective area of the exhaust grille for different distances in the unit were constructed, the outlines and sizes of the vortex zones were determined. Conclusions: the obtained dependencies can be taken into account when designing exhaust ventilation systems in buildings for various purposes.

Precast monolithic structural systems have higher resistance to accidental impacts than purely precast solutions. The deformation and force distribution in such structures is specific due to the concentrated shears at the contact joint of the precast and monolithic part of the section. However, the issues of taking into account the influence of the contact joints of the composite section on the deformation of structures in limit states as a result of realisation of a special design situation remain poorly investigated. The aim of the study was to investigate the influence of structural features of precast monolithic reinforced concrete multi-storey building frames on their deformation in the limit states caused by emergency impacts. The objectives of the study were to develop a methodology for numerical modelling of precast monolithic reinforced concrete structures under emergency conditions; to determine the stress-strain state of the elements of such frames in a special design situation using the proposed methodology; to compare the obtained results with the data of experimental studies; to assess the dynamic overloading of precast monolithic frame structures in a special design situation. Results. A numerical modelling technique is proposed and verified on the background of experimental data, which makes it possible to take into account the deformability of composite section elements at the formation of normal and longitudinal cracks in them along the contact joint. The results of the parametric study of the influence of the structural features of the contact joint are presented: the ratio of the strength of concrete of the precast and monolithic part of the section, the pitch of the transverse reinforcement bars, on the deformability of the frame elements and energy dissipation. Conclusions. It is shown that as the load increases from 0.2 to 0.6 of the operational load, the value of dynamic overloading decreases on average from 1.8 to 1.6.

The known solutions of polygonal arch designs have some disadvantages, which are expressed in significant material consumption due to the use of flange elements in the nodes, also these connections are more labor-intensive when assembling unified elements. Therefore, it is relevant to develop a new polygonal arch assembly and study its load-bearing capacity. The purpose of the work is to determine the actual load-bearing capacity of a new bolted connection of unified elements of a polygonal arch. In accordance with this goal, the following tasks were solved: a prototype of a new steel polygonal arch assembly and its testing methodology were developed; a full-scale test of the prototype was carried out with the determination of the actual stress level using strain gauges; a numerical modeling of the unit was conducted and the forces in the holes of the bolted connection were analytically determined; conclusions were made about the use of the unit in arched structures and further improvement of the design solution. Results. For the polygonal arch of a certain configuration and size, the authors determined the sections of the unified elements, designed the unit where bolts and their number were selected. These obtained data became the basis for creating a prototype unit. A full-scale test of a prototype was conducted with recording of the stresses in the elements. The values of stress distributions were obtained in the numerical model, as well as from strain gauge data during tests. The maximum load value according to the test results was 60.14 kN at the moment of stability loss of the element. Conclusions. The use of the proposed design solution in construction projects will reduce the material consumption of buildings by 10-20% compared to classical solutions due to the use of a non-flange assembly in arches.

Actively developing prefabricated monolithic housing construction, both in Russia and abroad, requires the development and theoretical basis for the calculation of prefabricated monolithic structures. In order to develop the theory of calculation of prefabricated monolithic bendable elements, the description of the stages of the stress-strain state of a prefabricated monolithic structure is proposed in this article. The feature of the formation of the stress-strain state of such structures is the gradual involvement of precast and monolithic concrete in the process of deformation and load perception. The research objectives are the following: to describe the stages of the stress-strain state of a prefabricated monolithic bendable element; to substantiate the proposed description of the stages based on experimental and numerical studies. Materials. The description of the process of forming the stress-strain state of a normal section of a prefabricated monolithic element is proposed in relation to the “classical” stages of a bendable reinforced concrete element proposed by Professor V. I. Murashev, depending on the qualitative change in the state of the materials (stretched concrete of the prefabricated part, compressed concrete of the monolithic part and longitudinally stretched reinforcement) at each stage. Results. Corresponding experimental and numerical studies of a prefabricated monolithic bendable element have been carried out, which confirmed the assumptions made. The feature of the conducted research was the step-by-step installation and loading. At the 1st stage, the assembly and loading of the prefabricated part took place, and at the 2nd stage, after laying the monolithic concrete and gaining the required strength, the prefabricated monolithic beams were additionally loaded until destruction. Conclusions. The proposed description of the stress-strain state of a normal section of a prefabricated monolithic bendable element conditionally divides the deformation process into “classical” stages, taking into account the qualitative changes in the state of materials during the phased installation and loading.

In modern conditions of development of nuclear power engineering and the use of special concretes and new types of structures in construction, the study of materials used at elevated temperatures under the action of long-term loads is of particular relevance. Existing methods of testing for creep of concrete under heating have a number of disadvantages: difficulty in maintaining stable temperature conditions, bulky equipment, impossibility to create high loads and lack of standardized approaches to such tests in Russian and international norms. In this regard, there is a need to develop a new, more efficient methodology that allows mass testing with high accuracy and minimal costs, as the existing methods according to the state standard are not applicable to high-strength concrete. The objective of the study is to develop an experimental methodology to investigate creep deformations of concrete at temperatures up to 90°C, and to develop a compact system for local heating of specimens, compatible with standard spring units for the possibility of setting high loads and using the existing measurement system. Results. An innovative three-component system including thin-plate heaters with automatic temperature control, providing uniform heating of specimens, combined with standard spring units and measuring equipment was proposed. The conducted tests confirmed the system performance: the stability of the temperature regime was achieved; the reliability of deformation measurements was ensured. The methodology allows conducting long-term experiments reliably and safely. Conclusions. The developed method has the following advantages: versatility: applicable for concrete, reinforced concrete and steel-reinforced concrete, including specimens with sheet reinforcement; cost-effectiveness: the use of serial equipment reduces testing costs; high accuracy: automation of heating and modernization of the measuring system minimize errors.

Well-known variants of subway tracks, which are presented in manuals, articles and patents of researchers, have their advantages and disadvantages. The pathways of reduced vibration are of the greatest interest to researchers. This article examines a path that has a number of advantages, the main of which are: reducing vibration from rolling stock to the track, increasing the service life of the structure, increasing the speed of laying half-sleepers, and ensuring the required geometry of the top of the rail heads. At the moment, there are few studies of the stress-strain state of half-sleepers, so there is a need to assess the bearing capacity and crack resistance of these structures. The purpose of the work: investigation of the operation of a half-scale made of heavy concrete reinforced with steel reinforcement under static load. In connection with this goal, the following tasks have been solved: experimental studies of half-pin samples have been carried out, the bearing capacity and the moment of cracking have been determined. To assess the reliability of the results of the experimental study, numerical studies were conducted in the Ansys software package. The moment of cracking and bearing capacity are determined taking into account the nonlinear diagram of concrete and steel work. Results. Based on experimental and numerical studies, the values of the bearing capacity and the moment of crack formation of the half-pin of the path of reduced vibration were obtained. Stress and strain diagrams were also obtained and graphically depicted. The results of experimental and numerical studies are compared. Conclusions. The significance of the research for the metro construction industry lies in obtaining the deformation and strength values of the characteristics of this type of half-sleepers, which make it possible to design structures for reduced vibration paths.

Problem statement. Strength calculations in design are the most important aspect of the construction industry as a whole. The method of calculating strength based on limit forces is currently acceptable, but not the main one. In accordance with the current code of rules SP 63.13330, the main method is to calculate the strength of reinforced concrete structures based on a nonlinear deformation model. It is assumed that this method is theoretically accurate, but in reality, its theoretical accuracy has not been proven. The purpose of the work is to evaluate the accuracy of both methods. The studies were carried out numerically using the finite element method. The objectives of the study are to build high-precision numerical models, compare the calculation results based on a nonlinear deformation model and based on the method of limit forces with each other and with the results of numerical modeling. Results. In the course of the performed research, it was shown that the calculation using a nonlinear deformation model is not theoretically accurate. Its accuracy almost coincides with the accuracy of the calculation of the limit forces. For short-term loads the difference in the results obtained by both methods does not exceed 2%. However, this calculation method requires programming skills from an engineer and is extremely sensitive to the algorithms used. The largest margin of error compared to the true strength of the sections turned out to be the same for both methods and was equal to 21%. Conclusions. It is shown that the main reason for the insufficient theoretical accuracy of the calculation method based on a nonlinear deformation model is serious violations of the law of flat sections in reinforced concrete beams and columns in the limiting state. In terms of accuracy, it does not exceed the calculation method of limit forces. The status of both methods must be equalized in regulatory documents. This will allow, without compromising accuracy, to significantly reduce the time required to perform some parts of the calculations, using the method of limit forces as the main one.

Problem statement. The need to reduce the clinker content in industrial cements to reduce energy costs and carbon dioxide emissions encourages the wider use of mixed binders with a high content of substituting mineral additives. At the same time, their use is associated not only with a decrease in the share of expensive clinker, but also with the need to impart improved construction and technical properties to concrete (water resistance, frost resistance, crack resistance, corrosion resistance). The authors propose a direction for the most effective use of mineral additives by producing low water demand cements, in which the share of clinker is minimized, and in terms of technical and environmental indicators they surpass not only mixed binders, but also all general construction Portland cements produced by global manufacturers. The aim of the study is to conduct a comparative analysis of the efficiency of traditional Portland cement and low water demand “carbonate” cement in terms of composition of hydration products and physical and mechanical properties in heavy concrete. The research objectives are the comparison of properties of general-purpose Portland cement and low water demand “carbonate” cement; assessment of water demand indicators of concrete mixtures, strength and clinker capacity of heavy concretes based on two types of binders; analysis of compositions of cement hydration products with the possibility of identifying the formation of new compounds. Results. The paper presents comparative results of physical and mechanical tests of cement stone and concrete prepared on the basis of general-purpose Portland cement and low water demand cement (LWC) with carbonate filler. The use of LWC-50 allows reducing the normal density of cement paste by 23.8%, the water-cement ratio of mortar and concrete mixture by 40 and 36.8%, respectively. The increase in strength after 28 days of hardening was the following: cement stone by 39%, cement-sand mortar by 62%, heavy concrete by 23.5%. According to the clinker capacity criterion, which is determined by the ratio of clinker content in the binder accepted per 1 m3 of concrete, LWC-50 is 2.3 times superior to Portland cement CEM I 42.5 N. The method of X-ray phase analysis was used to comparatively assess the composition of crystalline hydrates in the microstructure of cement stone samples. Conclusions. In terms of water demand, strength and clinker capacity criteria, “carbonate” low water demand cements are superior to traditional cement. It has been shown that during the hardening of “carbonate” low water demand cement, calcium hydrocarboaluminates are formed, which obviously contribute to its early intensive hardening and increased activity at the age of 28 days.

Problem Statement. The main problem of organic road binders is a significant deterioration in their properties both in the manufacture of asphalt mixtures and during the operation of road surfaces. The positive role of polymer modifiers, primarily styrene-butadiene-styrene thermoplastics (SBS polymers), is well known. However, their effective use is possible only if the required degree of swelling is achieved under the action of low molecular weight substances either from the composition of the initial bitumen or introduced additionally. The purpose of the research is to study the properties of mixed plasticizers of plant origin by differential scanning calorimetry. The objectives of the study are: to create mixed plasticizers of plant origin with different ratios of residual products of forest chemistry, as well as to evaluate their effect on low-temperature performance of petroleum viscous oxidized bitumen for road construction. Results. The study of the quantitative effect of the ratio of components in a mixture of plasticizers on their physical and technical characteristics was carried out using such commercial products as tall pitch (TP) and light tall oil (LTO). During the experiment, the method of differential scanning calorimetry was used, the research was carried out on the thermogravimetric and differential thermal analysis device. It is shown that in order to achieve the existing regulatory requirements for low temperature values of bitumen binders, it is advisable to consider a mixed composition based on the studied plasticizers of plant origin in the ratio TP/LTO = 40/60. With this ratio, the required level of low-temperature properties was achieved and increased compatibility in complex multicomponent bitumen compositions was noted in comparison with the canonical petroleum plasticizer, industrial oil, which can lead to a decrease in the temperature of bitumen brittleness and is an absolute advantage when using asphalt mixtures and asphalt concretes in the northern regions of Russia. Conclusions. The conducted studies demonstrate the effectiveness of using a mixture of large-tonnage plasticizers of plant origin to regulate the quality of bitumen binders. The expediency of using mixtures of various compositions is evaluated. The effective ratio of components for the tall pitch – light tall oil pair has been determined.

Problem statement. The depletion of high–quality traditional well-swelling montmorillonite clays for the production of expanded clay requires the use of corrective additives containing a calorific value of at least 3,000 kcal / kg, as a result of which swelling increases. Such tools for recycling secondary raw materials are used by advanced countries for environmental safety. Efficient recycling of large-tonnage waste from the fuel and energy complex in the production of expanded clay will significantly reduce the harmful effects on the environment and improve the company’s performance. The analyzed geography of the localization of processing plants showed that 85% of all coals extracted from the bowels of the earth are undergoing enrichment, including 68% in the Rostov region. The purpose of the work is to analyze the impact factor of sludge from flotation coal treatment on the functional properties and macroporous structure of expanded clay with the participation of bentonite clay. The objectives of the study are to determine the compositions of the resource sources being developed: chemical – oxide and element-wise, mineralogical and fractional, as well as technological parameters; to characterize the parameters of sludge from flotation coal treatment and bentonite clay for the creation of expanded clay; to recommend reasonable formulations for recycling large-tonnage coal-treatment sludge into mass production of expanded clay; to investigate the effect of coal-treatment sludge on the internal and external macroporous structure of expanded clay, taking into account the analysis of the formed closed pores. Results. Due to the increased carbon content in the flotation waste (C=10.77%) and its combustion during firing, gas is released, which contributes to an increase in the swelling coefficient. Expanded clay swelling is identified as the result of excessive gas pressure inside the micropores, contributing to their expansion, which is directly dependent on the viscosity of the pyroplastic melt. Conclusions. The study of expanded clay with a 5-10 mm fraction has shown that formulations containing 30% (composition No. 4) and 35% (composition No. 5) coal-treatment waste are preferred in terms of brand, the grade of which is M250, but composition No.5 does not meet the conditions for frost resistance. Thus, the optimal composition should include composition No. 4.

Problem statement. To address issues related to traffic management and the development of measures to improve the quality of transport services for the urban population, an objective assessment of the quality of street and road networks is necessary. The methods developed to date for assessing the quality of transport services are based on comparing the speeds of cars in the time period under study and the speeds of single cars. In order to form a reasonable approach to determining the indicators of the level of service and the level of convenience of traffic in the road network, it is necessary to conduct research aimed at determining the speeds of single vehicles. Such studies will become the basis of methodological support for determining the level of service and the level of convenience of movement on the street and road networks of medium-sized cities of the Russian Federation. The objectives of the work are: to measure the speed of vehicles in free conditions in a laboratory car and stationary observation posts and to statistically process the data obtained, to establish the boundaries of the level of convenience of movement and the level of service for traffic conditions on the street and road networks of medium-sized cities. Results. The paper presents the results of studies of the speeds of single cars on the road network of a medium-sized city (using the example of Vladikavkaz). According to the research results, the boundaries of the level of convenience of movement and the level of service on the network of streets of citywide, district and local importance are proposed. Conclusions. The research results are the scientific basis for determining indicators of traffic comfort levels on the streets of medium-sized cities in the traffic conditions of the Russian Federation.

Problem statement. Movement by land passenger transport plays a crucial role in the organization of public transportation services. To date, no methods have been developed to assess the quality of service provided to ground transport users, allowing them to take into account traffic conditions in cities of the Russian Federation. The purpose of the study is to develop a methodology for assessing the quality of service for users of land transport, including in traffic conditions in Russian cities. Research objectives. It is necessary to define criteria for assessing the quality of transport services for public transport users, their weight coefficients, assess the level of user convenience based on the results of field studies, and develop a methodology for assessing the quality of transport services. Results. The paper presents the results of field studies of the criteria for the quality of service for users of ground-based public transport on the Vladikavkaz road network. Based on the data obtained, criteria for assessing the quality of transport services and their weighting coefficients were determined, a model for assessing the level of convenience of movement for land transport users was proposed, the level of convenience of movement was determined based on the results of field studies, and the results were compared with data from direct surveys of passengers opinions on the quality of services provided. Conclusions. Based on the results of the study, a multifactorial model is proposed for determining the level of convenience of movement for users of ground-based public transport, which will allow a reasonable approach to assessing the quality of transport services for users of urban street and road networks.

Problem statement. Toll roads play a key role in the infrastructure of many countries, providing financing for the construction and maintenance of transport networks. However, the irrational location of toll collection points can lead to a decrease in the efficiency of the road system: an increase in congestion, user dissatisfaction, and loss of income for operators. The correct distribution of such points can stimulate an increase in traffic intensity in urbanized zones, as well as increase freight traffic between industrial clusters and regions, forming stable logistics corridors. The purpose of the work was to study the optimal placement of toll booths on toll roads based on the principles of Webers theory, aimed at minimizing the total costs while increasing the efficiency of road infrastructure using the example of the Vostok M-12 highway. To achieve this goal, the following tasks were solved: the transport and logistics infrastructure of cities adjacent to the toll highway was assessed; options for localizing toll collection points using Weber’s theory have been formed. Results. To optimize the placement of toll collection points on the section of the Vostok M-12 route, a geospatial analysis method based on the construction of triangular models was used. Their peaks were key transport hubs: Kazan – Izhevsk – Ufa; Izhevsk – Perm – Ufa; Perm – Yekaterinburg – Ufa. According to the study 5 charging points are required to minimize delays. Conclusions. For optimal placement of toll collection points, a spatial optimization method was applied based on the principles of minimizing costs developed by A. Weber. This problem is reduced to solving the linear programming model, where it is required to find the extreme value of the objective function within the given linear constraints. The use of triangular models with peaks in the key cities on the Vostok M-12 highway confirmed that this approach: demonstrates the influence of cargo flows and distance on optimal placement; optimizes the distance between charging points; takes into account the influence of urban agglomerations on the formation of logistics corridors.

Setting the task. In this paper, the urgency of the problem of waste disposal from solid fuel combustion is indicated. Due to the continuous process of fuel processing, a huge amount of waste is generated, which is not recyclable and is stored in landfills, occupying a significant area of free and potentially usable territories. The purpose of the work is to study the possibility of using ash and slag waste (fly ash) from the Reftinsky state regional power plant in road construction. To achieve this goal, the following tasks were solved: assessment of the chemical composition of the fly ash of the Reftinsky State regional power plant from the point of view of danger to human life and the environment; analysis of the stress-strain state of the retaining wall structure with backfilling from the soil improved by fly ash. Results. The assessment of fly ash as a material that is a waste of fuel processing at the state regional power plant has shown that fly ash does not pose a danger to human life and the environment if ash is used in various human activities. The effectiveness of the use of fly ash (namely, fly ash from the Reftinsky State Regional power plant) has been proven by conducting numerical experiments that illustrate the improvement in the design of the retaining wall and soil. Conclusions. The significance of the results obtained for road construction lies in the fact that the use of secondary resources, industrial waste, reduces the need for road construction materials and increases the efficiency of their use. The use of fly ash will potentially help to increase the volume of ash waste disposal at landfills and improve the environmental situation in the regions of the Russian Federation.

Problem statement. To assess the quality of a transport facility project, a joint analysis of many heterogeneous indicators of technical and economic characteristics and transport and operational properties of a transport construction project is required. Heterogeneous indicators complicate the assessment of the quality of a transport facility project, and existing quality assessment methods do not consider the stochastic and non-stationary nature of the composition and intensity of traffic flows. To avoid these difficulties when solving the problem, it is advisable to use the taxonomic analysis method. The purpose of the work is to develop a method for solving the problem of multiparameter assessment of the quality of a transport facility project. The objectives of the study are analysis of existing quality assessment methods, assessment of their advantages and disadvantages; development of requirements for the quality assessment method; disclosure of the essence and features of the application of the method for assessing the quality of a transport facility project. Results. The proposed approach to assessing the quality of projects allows choosing a reference object (project) and establishing the degree of similarity of the transport facility planned for construction with the reference. Conclusions. Using the taxonomic analysis method allows successfully solving the problem of multiparameter assessment of the quality of a transport facility project. The efficiency of the analysis increases with an increase in the number of heterogeneous independent quality indicators, which meets the requirements of a systematic approach to quality assessment.

Problem statement. One of the weak points of the prefabricated tunnel structure is the junction between the liner plates. The establishment of a technique that allows determining the physical and mechanical characteristics and operation of sealing profiles as part of the tunnel liner plates structure, taking into account relaxation processes in a stress-strain state, will increase the scope of application of rubber seals in structures. The purpose of the work is to determine the physical and mechanical methods for investigating the operation of sealing profiles as part of the structure of tunnel liner plates. The objectives of the study are: to analyze the existing domestic and foreign normative and technical documentation in the field of research of sealing profiles for sealing tunnel liner plates; to determine methods that allow evaluating the performance of sealing profiles in the structure taking into account relaxation processes; to conduct physical and mechanical studies of sealing profiles, according to methods that take into account relaxation processes during operation. Results. The analysis showed that the physical and mechanical characteristics of sealing profiles for sealing tunnel liner plates can be successfully determined according to the recommendations of “STUVAtec”. The test results of sealing profiles allow us to evaluate their performance as part of the tunnel liner structure, taking into account relaxation processes. Conclusions. Studies have shown that a comprehensive assessment of the physical and mechanical parameters of sealing profiles for tunnel liner plates according to the recommendations of “STUVAtec” makes it possible to evaluate the operation and behavior of sealing profiles as part of the structure.

Problem statement. Cement concrete pavements are used in a wide range of temperature and operational loads, which inevitably leads to a decrease in their transport and operational condition. To improve the operational reliability of cement concrete pavements of highways, it is necessary to develop recommendations for the correct purpose of sealing materials, taking into account the natural and climatic conditions of operation. In this regard, this paper will offer a review and analysis of world practices and recommendations for the selection of materials for sealing various climatic conditions and types of operation of cement concrete pavements of highways. Results: The article describes the features of sealing expansion joints of cement concrete pavements. Modern sealing materials are considered. The influence of climatic and operational conditions on the choice of sealing materials and the technology of sealing expansion joints is analyzed. New technologies are presented, including the use of nanomaterials and intelligent monitoring systems to increase the durability of sealing materials and the efficiency of sealing expansion joints. Conclusions: The results of the conducted research allow us to give recommendations on the selection of effective materials for sealing expansion joints, as well as to present further development of technology in this area, which will improve the transport and operational characteristics of cement concrete road pavements and reduce the costs of their repair and maintenance.

Problem statement. Modern standards place increased demands on the quality of the soils used in the foundation of the pavement, which stimulates the development and application of technologies for their reinforcement. However, currently, the use of man-made industrial waste in road construction is a particularly important problem. The development of technologies for soil stabilization and strengthening using steel production waste developed on the basis of alkaline modification as binders is relevant. The aim of this work is to conduct a comparative analysis of existing inorganic binders with the developed geopolymer binder for stabilizing the sub-grade of a highway. To achieve the goal, the following tasks were solved: study of the influence of Portland cement and unslaked ground lime on the strength characteristics of clay soil; study of the influence of steelmaking waste and geopolymer binder based on it on the strength characteristics of clay soil; determination of the effectiveness of the studied binders in stabilizing clay soils. Results. The strength characteristics of stabilized clay soil were obtained depending on various binders. It was found that the introduction of geopolymer binder in the amount of 2% and 4% into clay soil provides an increase in the adhesion area to 107.47 kPa and 134.13 kPa and a decrease in the angle of internal friction to 16.70 ° and 14.04 °, respectively. Conclusions. The conducted studies allowed to establish the nature of the influence of various binders on the strength characteristics of clay soil with a single-plane cut. It is shown that the geopolymer is not inferior in the obtained strength characteristics to clay soils stabilized by traditional binders. The obtained results are a prerequisite for further research of geopolymer binders in stabilizing and strengthening soils in road construction.

Problem statement. The technical level of soil reinforcement technology in road construction, especially clay, does not fully ensure the possibility of increasing the inter-repair service life of highways and limits the possibilities of using clay soils. One of the new approaches to increase the effectiveness of soil reinforcement technology is the use of complex modification of reinforced soils, which are classified as complex systems. In this regard, the application of the approaches of the theory of synergetics, which are among the advanced methods of scientific research in solving problems of self-organization of complex systems, is justified. The purpose of the work is to substantiate the application of methodological approaches of synergetics in the study of complex modification of reinforced soils in road construction. The tasks are formulated: to systematize the evolutionary and technical development of soil reinforcement technology, the level organization of the system using the example of the construction of road clothes with layers of complex reinforced soils and methods of modification of reinforced soils; to test the methodological approach of synergetics using the example of the application of complex modification of reinforced soils in the construction and operation of a highway. Results. For the first time, a scheme of the level organization of the system is proposed using the example of the construction of road clothes with layers of reinforced soils, classification of the stages of the evolutionary and technical development of technology and methods of modification of reinforced soils according to their functional purpose. A new approach has been developed to improve the technology of reinforced soils in road construction, consisting in a combination of applied types of functional modification (complex modification) based on the regulation of ongoing physico-chemical processes. Conclusions. The conducted research on the systematization of the achieved results using synergetic approaches is aimed at further development of soil reinforcement technology in road construction. Complex modification of reinforced soils is defined as one of the new methods of technology improvement. The use of complex modification makes it possible to design and build structures for road surfaces with an increased level of technical and economic efficiency and durability indicators.

Problem statement. In modern intelligent transport systems, video surveillance is one of the key tools for monitoring the traffic situation, detecting anomalies, recognizing objects, and optimizing traffic. When developing computer vision systems, the need for careful selection of the model architecture and its learning parameters in order to achieve high recognition accuracy is an urgent task. The aim of the work is to develop approaches to improve the management efficiency and safety of road infrastructure using big data and machine learning algorithms in intelligent transport systems. The objectives of the study are: analysis of big transport data processing models and establishment of their limitations; evaluation of neural network models of Faster R-CNN and YOLO object detection; comparative testing of various modifications of YOLO models trained on a single set of video frames of urban traffic. Results. Comparative testing of YOLO models of v8–v10 versions on real urban traffic was carried out with an analysis of the influence of hyper parameters and sensor configurations on accuracy and performance. The data obtained demonstrate the high efficiency of the proposed approach with moderate computational costs. The customized YOLO models showed a significant improvement in recognition accuracy while maintaining near-real-time processing. Connecting additional data sources allows you to increase the stability of the system in difficult weather and evening conditions. Conclusions. The significance of the results for the infrastructure lies in the possibility of implementing scalable intelligent transport systems solutions without retrofitting the road network facilities. The integration of YOLO-video analytics, short-term forecasting and adaptive management forms a sustainable and self-adjusting transport infrastructure. For the further development of intelligent transport systems, it is necessary to interact with cartographic services and mobile navigators, providing two-way data exchange and proactive informing of road users.

Problem Statement. The efficiency of transport systems aims to solve the following tasks: convenience, safety, and environmental friendliness of movement and environmental protection. The relevance of this study is due to the need to improve transport system efficiency in large cities by developing scientific and methodological tools for applying geographic information systems to transport systems in these cities. Currently, this process does not involve geographic information systems usage. The aim of this work is to develop a methodology for using geographic information systems in transport infrastructure. To achieve this goal, we have solved the following tasks: description of the methodology for creating geographic information systems for transport infrastructure and study of how geographic information systems can improve transport efficiency. Results. The study clarifies the requirements for these technical tools of traffic management in terms of applying existing regulatory requirements to them, as well as their mathematical description. The developed framework allows for the systematic organization of data and facilitates the transition to a unified system. The developed geographic information systems allows us to check the indicators of the level of engineering equipment and road improvement, which in turn affects road safety. One of the indicators is the availability of lighting at pedestrian crossings. An inspection was carried out for one of the districts of the city of St. Petersburg, containing 442 pedestrian crossings. As a result of the inspection, 7 sites were found to be in violation of the installation of lighting at pedestrian crossings. Based on the inspection process, a methodology for the application of geographic information systems to improve the efficiency of transport systems was formed. Conclusions. The application of GIS to improve the efficiency of transport systems will allow a comprehensive approach to the problem under consideration.

Problem statement. The need to develop rural housing in Kuzbass as part of the development of rural agglomerations requires the analysis of the experience gained in the practical construction and operation of rural housing in this region in the 1960s-1990s. This period was marked by attempts to bring the quality of rural housing closer to urban standards and by significant volumes of mass housing construction in rural areas. However, this experience has not been studied to any great extent. The purpose of this article is to determine the specifics of the evolution of regional features of rural housing architecture in the 1960s-1990s using the example of rural housing in Kuzbass. The objectives of this study are to analyze the typology of spatial, functional, planning, structural, technological, and stylistic solutions in rural housing built between 1960 and 1990. The relevance of the study is determined by the need to find modern ways to develop the residential areas of rural settlements in Kuzbass, most of which were built in the 1960s-1990s. Research results. The study revealed the following typology of rural housing architecture in Kuzbass in the 1960s-1990s: - single-family single-storey residential houses of the estate type; - single-family two-storey residential houses of the estate type; - two-family single-storey block residential houses of the estate type; - multi-family sectional residential houses. Conclusions. A distinctive feature of the development of rural housing architecture in Kuzbass in the 1960s-1990s was a significant decline in the importance of regional architectural and construction traditions in favor of the formation of unified “urban” standards of quality for the architectural environment in rural areas and the introduction of principles of standardization in its construction. The formation of such a model, which takes little account of local characteristics, has created serious problems for the development of rural housing architecture at present.

Problem statement. The relevance of this study lies in the need to systematize knowledge about the unique architectural and historical heritage of 19th-century stone madrasas in Kazan, as well as their role in shaping the cultural identity of the Tatar people within the context of religious education and urban development. The aim of this research is to conduct a comprehensive analysis of the 19th-century stone madrasas of the Old Tatar Settlement in Kazan, identifying their architectural features, stylistic affiliation, and historical significance. The objectives of the study are as follows: to identify the characteristic stylistic and compositional features of 19th-century stone madrasas in the Old Tatar Settlement and to systematize the collected data; to determine the influence of the historical and cultural environment on the formation of the architectural appearance of the madrasas; to analyze the historical transformation of the madrasas, assess their current condition, and identify prospects for the preservation of these cultural heritage sites. Results. The main result of this study is a systematized historical and architectural analysis of five landmark 19th-century stone madrasas in Kazan: Usmaniya, Apanaev, Marjani, Muhammadiya, and Muzaffariya. The research also examines their role in the cultural and historical context, as well as their current condition. Conclusions. The significance of the results for the field of architecture lies in the deeper understanding of regional features in the development of Islamic educational architecture within the Russian Empire. The study demonstrates the synthesis of the utilitarian needs of the Muslim community with the dominant architectural styles of the period in question, as well as documents valuable cultural heritage sites and the practices of their preservation.

The article is devoted to the problems of research and preservation of the identity of the historical residential buildings of this area. The relevance of the study lies in the fact that the objects of research, in the form of architectural elements and details of buildings, are an architectural and stylistic identifier of the identity of the Old Tatar Settlement. A scientifically based study of the architectural elements and details of buildings will contribute to the preservation of the identity of the Settlement and its sustainable development in the future. However, different methods and approaches are used to study the identity and identifiers of urban formations, including architectural elements and details. There is a problem of selecting from the variety of approaches and methods those that will be necessary and logical for studying the historical and architectural environment of the Old Tatar settlement of Kazan in order to identify its architectural and stylistic features. The objects of research are architectural elements and details of buildings of various types and stylistic trends of the late 18th and early 19th centuries. The objects of research are architectural elements and details of buildings of various types and stylistic trends of the late 18th and early 20th centuries in the ethnic district of Kazan – Old Tatar settlement. The purpose of the study is to identify the methodology (approach) and methods applicable to the study of architectural elements and details of buildings, as one of the important identifiers of the identity of the architectural and historical environment of the settlement. The objectives are: to analyze the scientific bibliography on the research topic; to develop a methodological approach to the study of morphotypes of residential buildings; to propose methods for the study of architectural elements and details as a separate layer (identifier) of the identity of the Old Tatar settlement of Kazan. The research methodology is based on a comparative analysis of well-known techniques and research methods described in scientific publications on the study of the architectural and stylistic design system of buildings in various regions and time periods. The result of the study (conclusions) are the methodology and research methods selected for the study of architectural elements and decor of residential buildings in the late 18th and early 20th centuries of the Old Tatar settlement of Kazan. The significance of the results obtained lies in the scientifically sound choice of an approach and methods for the study of architectural elements and details for further identification of the architectural and stylistic identity identifier of the Old Tatar settlement.

Problem statement. The main problem in studying the formation of architectural education in Kazan is the insufficient amount of information about its origins and the persons who participated in its development. One of them is the architect Jacob-Heinrich Bernardovich Rusch, about whose teaching contribution practically nothing is known. The purpose of the work is to study and identify the contribution of the architect J.B. Rusch to the formation of architectural education in Kazan. The objectives of the research are the analysis of the newly discovered materials related to the architect’s teaching activities from 1880 to 1900 in Kazan, identifying the connection between the architectural practice of Heinrich Rusch and the training of young specialists, systematizing and generalizing the collected information confirming the importance of the architect in the development of architectural education in Kazan. Results. The article presents the results of work on the newly identified archival data, publications by J.B. Rusch and historical facts. Publications authored by Heinrich Rusch have been discovered. The article describes the architect’s activities as a teacher of technical drawing, a member of the Society for the Education and Supervision of Students in Craft Workshops and Kazan branch of the Imperial Russian Technical Society. Conclusions. As a result of the analysis of the materials, the architect’s contribution to the development of architectural education in Kazan was determined, and new areas of professional activity of J.B. Rusch were identified, such as teaching, compiling and publishing textbooks, and the establishment and management of a technical drawing school.

Problem statement. The Syuyumbike Tower is an architectural monument of world importance, located in the Kazan Kremlin complex under the protection of UNESCO. According to the research of typological and stylistic characteristics, the Syuyumbike Tower is attributed by the author as an object of civil architecture for public and religious purposes, dating back to the period of the Kazan Khanate. The study of architectural and structural elements will allow us to determine its belonging to a particular historical period and to clarify the dating range that exists within different centuries. The purpose of the study is to determine the architectural and structural features of the Syuyumbike Tower, to check the possibility of its belonging to the Kazan-Khan period on the basis of the identification and analysis of its structural elements. Research objectives: 1. To identify and describe the architectural and structural elements of the walls and foundations of the Syuyumbike Tower; 2. To identify constructive analogues in some objects of the Russian-European, Bulgaro-Tatar, Middle Eastern and Central Asian Middle Ages. 3. To determine the architectural and structural features of the Syuyumbike Tower. Results: For the first time, a comprehensive study of the architectural and structural elements of the Syuyumbike Tower has been undertaken, a significant amount of new research materials has been introduced. The Syuyumbike Tower differs from its well-known analogues in Russian architecture of the 17th and early 18th centuries in terms of the foundation, brick size, mortar, ceilings, etc.; it is close to certain construction techniques of the Bulgaro-Tatar, European, Russian-Italian Middle Ages. The features of the design solution are archaic foundation, geometrically harmonized step-by-step ascending structure of the volume with gradual thinning of the walls, forged iron rods, tie rods with anchor fasteners, lime-alabaster mortar with the inclusion of charcoals, brick similar to the brick of the Kazan Khanate, intra-tiered closed-elongated four-tray brick vault. Conclusions. The significance of the obtained results lies in the confirmation of the scientific hypothesis about the possibility of the Bulgaro-Tatar origin of the Syuyumbike tower as a unique gate-tower, polygonal-tiered structure, built according to the design of an outstanding architect who mastered the methods of erecting tower structures characteristic of the European, Russian-Italian and Bulgaro-Tatar architectural schools.

Problem statement. The work is devoted to the problem of identifying the influence of classicism architecture on the formation of national features of Tatar architecture in Kazan province. The relevance of the study is based on the fact that, due to natural causes, there are fewer and fewer monuments of Tatar folk architecture, which had national characteristic features in the late 19th and early 20th centuries. At the same time, the aspects of the influence of urban architecture of classicism and the forms of their manifestation in Tatar architecture have not been studied. The article examines the peculiarities of the manifestation of the forms and techniques of classicism in the wooden rural architecture of the Tatars. The purpose of the research is to identify and study aspects of the influence of urban classicism architecture on Tatar folk architecture. Research objectives: to analyze the conditions of the development of wooden classicism in Russia; to identify aspects and forms of the influence of classicism on Tatar folk wooden architecture; to establish the importance of classicism elements in the formation of national identity of Tatar folk architecture. The main result of the study is the identified aspects and forms of the influence of classicism on Tatar folk wooden architecture and their role in shaping its national characteristics. Conclusions. A peculiar architectural and stylistic system of design of manor complexes and residential buildings has been formed in Tatar folk architecture, which has become a manifestation of its national identity. The development and preservation of this system in Tatar rural architecture during the Soviet period, and partly at the present time, testifies to the importance of the research results for the history of architecture and construction practice in Tatarstan.

Urban planning must consider the possibility of economic shocks, due to which the designed space may lose safety and become a problematic zone requiring special control or revitalization. The aim of the study is to identify key factors of crime-preventive planning of the urban environment, taking into account the socio-economic and cultural characteristics of the territories, with the focus of analysis on the contradictions between theoretical concepts and their practical implementation in conditions of economic instability. The objectives of the study are the analysis of the criminogenicity of certain images in the urban environment, identification of the relationship between urban and environmental planning, socio-economic factors and crime, as well as the development of universal crime-preventive solutions in urban environment planning. The result of the study is a critical review of urban and criminological theories and their practical application in various urban contexts, as well as the identification of natural forms not subject to vandalism. Dense low-rise development, provided the organization of pedestrian flows and visual accessibility of spaces, can help reduce criminogenicity by improving natural control by residents. It has been revealed that some urban theories are ineffective in poor and unstable countries, which is why a crime-preventive approach to planning is recommended, reducing the costs of control and maintenance. Conclusions: the significance of the results for architecture and urban planning lies in the need to integrate natural and theoretical anti-vandal solutions, mixed-use development, in improving the visibility of the environment, and in combining architectural solutions with the prediction of deviant pedestrian behavior.

In the modern world, parks serve not only as a recreation area for city residents, but also as a place for sports. They help reducing stress and negative emotions that are inherent in life in any large modern city. Parks created within the city borders are a unique phenomenon, since many of their elements can only be implemented in urban conditions. When creating concepts for park areas, social, health and planning aspects are of key importance. They are fundamental when creating park spaces, since they directly affect the standard of living of the city. These factors should be optimized by making informed planning decisions. The purpose of the work is the combined and detailed development of health, social and planning aspects in the design of park areas. In the process of developing the set goal, the authors formulated the following tasks: identify the most important aspects in the design of park areas; develop the selected aspects as fundamental criteria; conduct an analysis of modern trends based on a sociological survey; suggest options for solving the problem by designing park areas taking into account planning solutions. The authors conducted an extensive study covering various age groups of the population using a sociological survey. Based on the data obtained, a diagram was developed confirming the importance of having exercise equipment and sports grounds in parks. Based on the data obtained, a demographic map was developed that allows for a more accurate determination of the needs of residents and the placement of park areas taking into account their specific characteristics. Based on the work performed, the need for a comprehensive consideration of the aspects under study and the compliance of the topic under consideration with modern national projects was confirmed. In conclusion, the authors emphasized the importance and necessity of developing park areas, as well as the need to develop an economic aspect.