Problem Statement. The quality and reliability of engineering geological surveys largely determine the reliability and durability of design solutions. The primary method for obtaining mechanical characteristics is sampling and subsequent laboratory testing. The relevance of the study lies in a comprehensive approach to assessing the quality of soil laboratory samples, which considers regional specifics of the soil environment and the capabilities of contracting organizations. The aim of this study is a comprehensive assessment of the quality of soil laboratory samples and the development of a model for their prediction based on identified factors. The research objectives include creating a database of regional engineering geological surveys, determining the quality of soil laboratory samples and analyzing the influence of individual parameters, performing a correlation analysis between the identified features and soil sample quality, defining a model for predicting soil sample quality based on regression analysis, and solving an inverse optimization problem using the Monte Carlo method to assess the factors ensuring high-quality soil samples. Results. Specific results of the influence of sampling depth and soil physical characteristics on the quality of laboratory samples were obtained. Based on correlation analysis, factors for regression analysis were selected, and two models for predicting soil sample quality were developed: a machine learning-based model and an analytical model. The subsequent application of these models in inverse optimization made it possible to establish the relationships between sampling depth and the consistency of clayey soils that ensure the collection of high-quality samples. Conclusions. Conclusions were formulated regarding the quality of engineering geological surveys based on the quality of soil laboratory samples; factors affecting soil sample quality during sampling were identified; and a model for predicting soil sample quality was proposed.

Problem statement. In the practice of building reconstruction involving underground construction, controlling foundation deformations is of critical importance. Traditional criteria based solely on settlement values and their relative unevenness are often insufficient for accurate risk assessment. The objective of the work is to develop and validate a method for the quantitative assessment of foundation deformations using additional parameters, such as curvature and the difference in tilt angles at the base of the foundation. The research tasks are: 1. To analyze the permissible deformation limits for reconstructed buildings according to various regulatory documents; 2. To develop algorithms for calculating the derivatives of settlement using cubic spline interpolation for an existing reconstruction project, and to analyze the spatial distribution of deformations; 3. To compare the calculated foundation deformations with regulatory limits and with recorded instances of structural defects. Results. The proposed method was implemented in the settlement analysis of the Middle Trading Rows building in Moscow. The resulting diagrams of settlement, inclination angles, and curvature of the foundation base made it possible to identify zones of maximum ground deformation between geodetic benchmarks that were previously unrecognizable using traditional methods. Conclusions. The use of curvature and differential tilt angle as additional evaluation criteria significantly improves the accuracy of assessing foundation conditions in reconstructed buildings. The method can be integrated into geotechnical monitoring systems for urban reconstruction projects.

Problem statement. In the center of Tyumen, surrounded by dense urban (including historical) development, the construction of a five-story building with an expanded two-level underground space 6.3 m deep is currently being completed. The excavation of deep pits, unloading, and overloading of the soil base composed of silty-clay soils in constrained conditions contribute to additional settlement of the surrounding buildings, particularly affecting heritage buildings sensitive to such deformations. As part of emergency stabilization measures for the historical building’s settlement, soil cementation using the collar technology was performed. The purpose of the work is to investigate changes in the soil’s stress state during soil cementation by collar technology while work process of the emergency stabilization measures at a cultural heritage site. The object of research consists of silty-clay soils of stiff-plastic to soft-plastic consistency forming the soil base of the historical building, located within the influence zone of new construction involving deep excavation works. The subject of research is their stress state during and after emergency protective measures involving compensation grouting. Tasks include: - investigating changes in the stress state of the historical building’s silty-clay soil base during soil cementation by collar technology; - analyzing the stress relaxation process in silty-clay soils from soft-plastic to stiff-plastic consistency during and after grouting; - analyzing the results of compensation measures to stabilize the settlement of the cultural heritage site. Results. The main results of the study include new data on stress development in silty-clay soils of the historical building’s soil base during cementation by collar technology and its relaxation after the completion of the works. Conclusions. The ability to assess the impact of grout injection during soil cementation on changes in the stress state of various soils, enabling the prediction of their future behavior, highlights the practical significance and relevance of the research.

Modern underground construction technology involves installing barrettes from the ground surface, followed by excavation. The main issue addressed in this article is assessing the influence of excavation depth on the bearing capacity of these barrette piles, which is a topical issue in modern geotechnical engineering. The objective of this study is to investigate changes in the stress-strain state of a soil mass interacting with a barrette pile installed from the ground surface after excavation. The following objectives are addressed: developing a computational model and conducting numerical studies of the barrettes interaction with the surrounding soil; identifying patterns of stress changes on the lateral surface of the barrette pile after excavation; and, based on these patterns, developing proposals for improving the method for calculating the bearing capacity of a single barrette pile on soil, taking into account excavation. Results. The numerical studies revealed patterns in the variation of normal soil stresses on the lateral surface of barrette piles depending on excavation depth. An analytical relationship was proposed for determining the reduction factor for specific soil resistances on the lateral surface of barrette piles driven from the ground surface after excavation to design elevations. Calculations were made of the bearing capacity of barrettes of various lengths in clay soils at excavation depths ranging from 9 to 15 meters, taking into account reduction factors. Conclusions. A comparison of the soil bearing capacity of barrette piles in clay soils, determined in accordance with the Pile Foundation Code of Practice, and taking into account the reduction in specific resistances on the lateral surface, revealed a bearing capacity reduction of at least 10% depending on excavation depth.

Problem Statement. The main problem in calculating horizontally loaded pyramidal piles lies in the absence of engineering calculation methods in regulatory technical documentation that take into account the specifics of their operation within soil masses. The aim of this study is to develop an engineering method for calculating such pyramidal piles subjected to horizontal loading. The objectives include analysis of experimental studies, construction of a pile calculation model, and development of a calculation methodology. Results. Static tests on cast-in-place pyramidal piles for horizontal load were conducted, resulting in graphs illustrating the relationship between applied load and pile displacement. It was found that the nature of horizontal displacements demonstrates pronounced nonlinear behavior across a wide range of potential shifts. An engineering calculation method for horizontally loaded pyramidal piles has been developed. This approach allows determination of horizontal displacement and rotation angle of the pile head, along with bending moments and shear forces along the pile shaft. Calculations show good agreement with experimental data when displacements are small (~10 mm); however, deviations from actual values reach approximately 11-29% on average. Conclusions. The significance of these findings for the construction industry lies in providing a method which expands the scope of application for pyramidal piles due to their economic efficiency compared to constant cross-section piles. It has been demonstrated that taking into account the nonlinear behavior of the soil foundation is necessary for an adequate description of all ranges of horizontal displacements of piles.

Problem statement. The multicomponent nature of gypsum-cement-pozzolanic binder and concrete based on it predetermines the polyrecipe which is dictated by the quality of all components. A rational approach to solving this problem is a planned experiment, which allows obtaining a reliable and fast result with minimal costs. This is achieved by the correct choice of the experimental plan. Therefore, the purpose of this work is to establish independent factors influencing the behavior of responses and creating a dependency model. To achieve this goal, the following tasks were solved: establishing a set of gypsum-cement-pozzolanic binder components influencing the behavior of the most important characteristics of the hardened matrix, namely, the amount of cement, active mineral and chemical additives; determining the mathematical plan of the experiment; establishing independent factors influencing the behavior of responses and creating mathematical models of the dependencies of compressive strength, softening coefficient and water resistance on the composition of gypsum-cement-pozzolanic binder. Results. The paper presents the results of a study of the physical and physical-mechanical properties of gypsum-cement-pozzolan binder, depending on its component composition. Using mathematical models constructed after mathematical processing of the results of the planned experiment, the task of selecting the component composition of gypsum-cement-pozzolan binder was solved, for which the compressive strength after 28 days and the softening coefficient would be the highest, and the water absorption would not exceed 9%. Conclusions. The significance of the obtained results for the construction industry lies in the optimization of the gypsum-cement-pozzolanic composition formulation and the selection of effective modifying additives, which will expand the areas of application of these materials and increase their competitiveness in the construction market.

Problem Statement. To extend the service life of concrete and reinforced concrete structures, the application of protective polymer-based coatings is crucial and necessary. The primary requirements for this class of materials include high wear resistance and good adhesion to the substrate. In modern practice, epoxy polymers modified with metal oxides are widely used. The properties of the resulting material mainly depend on the type and concentration of the filler, its degree of dispersion, and surface characteristics. The aim of the work is to study the effect of micro- and nano-sized zinc oxide particles on the tribological and adhesive properties of epoxy polymer. The objectives of the study are to substantiate the choice of modifiers and evaluate their impact on the tribological and adhesive properties of epoxy polymers. Results. The paper presents the results of determining the tribological and adhesive parameters of epoxy polymers modified with zinc oxides of various dispersity. The best performance characteristics were demonstrated by epoxy polymers with nano-zinc oxide, in particular, it was possible to increase the shear and peel strength by 14% and 18%, respectively, as well as hardness and abrasion resistance by 10%. The roughness changes more significantly in coatings with micron-sized zinc oxide, demonstrating the greatest profile irregularity height. Conclusions. The significance of the obtained results for the construction industry lies in the possibility of increasing the durability of concrete and reinforced concrete structures through the application of wear-resistant epoxy polymers.

Problem statement. Modern construction closely interacts with the chemical industry. As a result, there is an annual increase in construction waste, chlorine- and fluorine-containing materials, which are then converted into highly hazardous compounds of a cumulative nature and have a negative effect on the environment and humans as a whole. The cheapest and most promising method of waste disposal is pyrolysis, which can be low- and high-temperature. An experimental study of the yield of combustion products is economically unjustified, since the composition of the waste is constantly changing, and research using numerical methods is a promising area of research regardless of changes in the composition. The purpose of the work is to predict the composition of the decomposition products of low-temperature pyrolysis in order to identify toxic compounds. The objectives of the study are to find the composition of the decomposition products of construction waste by low-temperature pyrolysis in specialized furnaces using numerical methods and to obtain data necessary for analyzing the toxicity of components, as well as for studying the possibility of their secondary use. Results. A diagram of the low-temperature pyrolysis process in a specialized furnace is given. The mole fractions of the products of decomposition by low-temperature pyrolysis of butadiene, isoprene, chloroprene rubber and fluororubber were obtained. Toxic compounds produced using this method of disposal were identified - carbonyl fluoride F2CO, hydrogen fluoride HF and hydrochloric acid HCl. Conclusions. It has been shown that the products of construction waste disposal can vary across the entire range of hazard classes of substances (I - IV) depending on the specifics of the building construction processes. Highly toxic compounds were obtained at the output of low-temperature pyrolysis decomposition of construction waste - carbonyl fluoride F2CO, hydrogen fluoride HF, hydrochloric acid HCl. Methane CH4 and carbon C obtained in the calculations can be selected for secondary use.

The relevance of the research is due to the intensive development of high-rise construction. The traditional design of smoke ventilation often does not take into account the dynamics of the fire and the interaction of smoke extraction and compensation systems. According to the Ministry of Emergency Situations of Russia over a 5-year period, 68% of fires in apartment buildings are accompanied by critical smoke on evacuation routes, especially in buildings with open-plan layouts. Problem statement. The study is aimed at evaluating the effectiveness of solutions for smoke ventilation systems in conditions of fire development using the example of a 26-storey residential complex. The purpose is to analyze the interaction of smoke extraction and air compensation systems in inter-apartment corridors at the stage of fire power growth and to develop a methodology for evaluating the effectiveness of fire control during its unsteady development. Research objectives: based on a normative methodology, calculate the power of the fire source and the growing oxygen consumption, taking into account the parameters of the room and the fire load. The mass and volume consumption of the burning products being removed, their temperature and density were determined. The development time of the fire source (30 minutes to peak power) and the flame spread have been calculated. Results show, that smoke ventilation systems that provide a volumetric balance between the removal of the smoke and gas mixture and the supply of compensation air prevent excessive underpressure at the doors (pressure drop 150 Pa). In 30 minutes, the fire load burns out by 50%, while the volume of compensation air does not exceed critical values capable of stimulating the development of the fire. Conclusions. A calculated approach to the design of smoke ventilation, which ensures a volumetric balance, increases the safety of evacuation and complies with regulatory requirements. The results are relevant for apartment buildings, where the correct operation of systems is critical to minimize risks. The study confirms the need to take into account the dynamics of fire and the interaction of ventilation systems.

Problem statement. In the context of rapid urbanization and the standardization of cultural practices, there is a threat of losing the distinctive traditions and linguistic characteristics of local communities. This leads to a decline in cultural diversity and a weakening of the population’s sense of belonging to their region. Preserving and updating historical and cultural heritage is not only an important tool for maintaining cultural continuity but also a factor in sustainable regional development, fostering a positive image of the region, and strengthening civil identity. The article presents a stage of a comprehensive study aimed at developing approaches to strategic spatial planning of historical settlements of regional importance in the Republic of Tatarstan in the context of sustainable development. At the previous stage of the study, the features of urban development were studied and the typology of historical settlements of regional significance of the Republic of Tatarstan was identified. The purpose of this article and the corresponding stage of the study is to develop a methodology for strategic spatial planning focused on the sustainable development of historical settlements, taking into account the specifics of the region. The objectives are to describe the general scheme of the methodology; to determine the principles, stages of implementation and content of the methodology for different types of settlements. Results. The main results of the study are that the proposed methodology will make it possible to identify models and scenarios for the spatial development of settlements that take into account the balance between the preservation of historical and cultural sites, the sustainability of infrastructure and socio-economic development, depending on the scale and role of the settlement in the historical and cultural framework. This will allow for the preparation of specific recommendations and proposals to improve urban planning solutions and spatial planning policies, as well as tools for integrating cultural heritage sites into the spatial development of agglomerations and the region, taking into account the resource base of the settlements. Conclusions. The significance of the results obtained lies in the fact that the proposed methodology forms a roadmap for strategic spatial planning of historical settlements of regional significance in the Republic of Tatarstan and provides a basis for the technical specifications for the development of master plans for these settlements.

Problem statement. One of the consequences of the accident at the Chernobyl nuclear power plant was the formation of cultural trauma among the population living in the radionuclide-contaminated territories of the Gomel region, the Republic of Belarus. Creating a safe environment for the sustainable development of a local community requires a socio-psychological impact on the population through the environment. The principles of architectural and planning rehabilitation of radionuclide-contaminated territories proposed by the author directly affect the living conditions of the local population, and therefore it is necessary to conduct a systematic analysis in relation to the general methodological principles of rehabilitation. The purpose of the work is a systematic analysis of the differences between architectural and planning rehabilitation and the general methodological principles of rehabilitation of territories contaminated with radionuclides. The objectives of the study are to study the factors influencing the course of architectural and planning rehabilitation. Analysis and systematization of the principles of the general methodology of rehabilitation. Identification of criteria and parameters for comparison. Substantiation of the features and specifics of the application of principles in architectural and planning rehabilitation against the background of general methodological approaches, identification of advantages and disadvantages. Search for further ways of development and practical implementation of the research results. Results. The main results of the work are that the analysis revealed differences and relationships between the principles of architectural and planning rehabilitation and the general rehabilitation methodology, which facilitates the implementation of the results through various government development programs in the affected regions. Conclusions The significance of the results obtained lies in the fact that the use of architectural and urban planning techniques in the rehabilitation of radionuclide-contaminated territories is formed into an independent approach when working with settlements in such territories. Further research should be aimed at developing specific recommendations for the application of the principles of architectural and planning rehabilitation for various types of settlements and different levels of radiation pollution.

Problem statement. In the Republic of Tatarstan, thirteen municipalities have the status of historical settlements, but many of them do not have sustainable development concepts, which leads to the destruction of their historical urban fabric. The article presents one of the stages of a comprehensive study devoted to the search for urban planning tools for strategic planning of historical settlements of regional importance in the Republic of Tatarstan. The purpose of this stage is to test the previously developed strategic planning methodology for historical settlements of regional significance using the example of Mamadysh. Tasks: adaptation of the methodology taking into account the unique urban planning features of Mamadysh, development of strategic solutions, including the spatial organization of the historical center and service areas, integration of the city into the network routes of the Kama agglomeration, as well as the formation of proposals for economic development models. Results. As a result of the research, a methodological framework was formed that will allow defining the terms of reference for the development of strategic planning directions and the structure of the master plan concept for Mamadysh. Conclusions. The data and conclusions obtained can be used to further improve the regulatory framework and develop comprehensive programs for the development of historical settlements, which will contribute to the preservation of their historical and cultural value and sustainable socio-economic development.

Problem Statement: In the context of socio-economic transformations and Azerbaijans integration into the global community, there is a need to assess and modernize the tourism infrastructure to stimulate regional development. The Ganja-Gazakh settlement system has been selected as the subject of the study due to its significant tourism and recreational potential and the observable problems in infrastructure development. Objective of the study: To assess the current state of the tourism infrastructure in the Ganja-Gazakh settlement system by identifying main problems and determining directions for its improvement. To reach the objective following tasks were set: to analyze the development dynamics of hotel and health resort infrastructure of the region over the period from 2006 to 2024; to assess the areas provision with accommodation, food service facilities and transport accessibility; to identify territorial differences and problems of infrastructure development. Results: An increase in the number of hotels, particularly in the city of Ganja, was observed, alongside a simultaneous decrease in one-time accommodation capacity and the number of rooms. Uneven infrastructure development across the districts was identified: active development in Ganja but stagnant development in several other areas. Insufficient development of public catering services and limited use of water and rail transport for tourism purposes were also noted. Conclusions: The tourism infrastructure of the Ganja-Gazakh settlement system is underdeveloped and requires both quantitative and qualitative improvements. A high territorial differentiation in infrastructure development was revealed. The main problems are the shortage of accommodation and food service facilities and the underutilization of the region’s recreational potential, which diminishes tourism’s contribution to socio-economic development.

Problem statement. The architecture of functioning madrasahs in Russia represents a unique stratum formed under the complex conditions of reviving a historically interrupted building tradition. The resulting stylistic diversity, which reflects an active search for a new confessional identity, has not yet received proper scholarly systematization. This fact determines the relevance of this comprehensive study. The aim of the research is to conduct a comprehensive architectural-stylistic analysis and a study of the exterior morphology of functioning madrasah buildings in Russia to identify their typological features and key development vectors. The research objectives are: to develop a classification of architectural types of functioning madrasahs in Russia based on the analysis of their genesis – from the preservation of historical heritage and the adaptation of secular buildings to new construction; to identify and characterize the main stylistic trends in madrasah architecture, establishing their connection with the change of socio-political paradigms in Russia; to analyze the morphological features of the buildings (number of storeys, total area) to identify and describe various regional models of the Islamic education system organization; to outline prospects for further research in this area, including a more in-depth study of regional architectural schools and the creation of a basis for developing evidence-based design recommendations. Result. The main result of this study is the authors’ proposed classification, which identifies four architectural types of functioning madrasahs based on their genesis: historical-architectural heritage, adapted functionalism, post-soviet retrospectivism, and the modern hybrid type. Conclusions. The significance of the obtained results for architecture lies in the creation of an evidence-based foundation for the analysis, preservation, and reconstruction of Islamic educational architectural objects. The findings open up prospects for further research aimed at developing practical recommendations for the design of modern madrasahs in Russia.

Problem statement. The history of the appearance of specialized buildings for the treatment and rehabilitation of military personnel in the past, namely from the reign of Peter the Great to the period of the First World War presents a subject of scientific interest. An important point here is the participation of monasteries in providing and caring for the wounded and crippled of military operations at the initial stage of the formation of the future hospital and post-hospital treatment service, attracting former soldiers and officers to monastic life. The purpose of the study is to identify preserved objects related to our history, but undeservedly forgotten, in particular, the history of Invalid Houses in the second half of the 19th century and the beginning of the 20th century, the role of the Raifa Monastery in the appearance of such structures on its territory, as well as the determination of the historical and cultural value of the preserved buildings belonging to the complex of the Invalid House. The objectives of the research are to search for and analyze materials related to the description of the territory of the Invalid settlement; the history of the creation of almshouses, hospitals in the Russian Empire and invalid houses for the veterans of the First World War; the identification of architectural and planning features of the construction of hospitals and almshouses in the second half of the 19th century and the beginning of the 20th century, as well as the influence of architectural classicist traditions on rural (wooden) architecture at the end of the second half of the 19th century and the beginning of the 20th century on the territory of the Raifa settlement. Results. Field surveys of buildings located in the village of Sadovy (formerly Invalid), as well as studies of archival materials, confirmed preliminary data that these wooden buildings are part of the Invalid house, which was built on the basis of a model project. Conclusions. The obtained materials can serve as the basis for the formation of an application for the designation of a landmark site of the territory with preserved wooden buildings of the former complex of the Invalid House.

Problem statement. A part of the creative method of Kazan architects in the 1950s was the introduction of ornamental compositions dating back to historical ornamental complexes into the compositionally responsible and most visible parts of facades. Many of them have been adequately preserved, and in order to understand the regional features of the formation of the Kazan architectural school, it is necessary to study them in detail. The purpose of the study is to determine the methodology for constructing ornamental compositions on the facades of residential buildings in Kazan in the 1950s. Research objectives: to study bibliographic sources on the topic of the research; to identify and conduct a field survey of the most expressive in terms of the use of regional ornamental complexes of residential buildings built in the 1950s in Kazan; to describe and analyze the arrangement of ornamental compositions. Result. As a result of the conducted research, the most expressive from the point of view of the use of regional ornamental complexes designer residential buildings were identified and examined in kind: residential building in N. Ershova Street, 14/2, residential building in B. Krasnaya Street, 29, residential building in Pushkin Street, 58, residential building in Levo-Bulachnaya Street, 42. Graphic tables were compiled containing the general appearance and fragments of the facades of the residential buildings under study. Conclusions. The method of constructing ornamental compositions on the facades of residential buildings in Kazan in the 1950s was based on the synthesis of regional ornamental heritage, classical form-building techniques and the symbolism of socialist realism - this synthesized method created the basis for the formation of the decorative system of the Kazan architectural school of the period under consideration. The principles of constructing ornamental compositions for the designer residential buildings of Kazan were the same as for large public buildings of the 1950s. Ornamental compositions were used in compositionally responsible and most visible parts of facades - wall panels, capitals of columns and pilasters, cornices, frames of openings, architectural and artistic railings of balconies, compositions were predominantly of plant origin and originated in the 3rd and 5th historical regional ornamental complexes.

Problem statement. The article is devoted to identifying the features of the development and implementation of the Kazan plan of 1838 and its version after the fire of 1842. The study fills a gap in the study of the mechanisms of interaction between planning participants and plan adjustments, their real impact on the formation of the architectural and spatial structure of the city. The relevance of the study is due to the fact that the features of the development and practical implementation of these plans have not been studied. At the same time, they are of great importance for determining their role in the formation of the architectural and spatial development of Kazan until the beginning of the 20th century. The aim of the work is to identify the features of the creation and implementation of the regular plans of 1838 and 1842, to determine the role of F.I. Petondi and to establish their significance for the urban development of the city. The tasks include: reconstruction of the development process of the regular plan of Kazan in 1838 and its version of 1842 by provincial architect F.I. Petondi; establishing the nature of corrections to the original plan based on the documents of the provincial construction commission; identifying the features of plan changes during implementation after the fire of 1842; determining the range of participants in the process of reworking and implementing the plan during the period under review; assessing the significance of the regular plan of 1838 and its version of 1842 in the development of the architectural and spatial structure of the city. Results. The features of the 1838 plan and its adjustments after the 1842 fire have been identified. Documents of the provincial construction commission have been introduced into scientific circulation, making it possible to reconstruct the process of plan formation. Conclusions. The features have been identified and the leading role of F.I. Petondi in the development of the regular plan of Kazan and the implementation of its updated version after the 1842 fire has been proven. It has been established that, alongside F.I. Petondi’s original proposals, the suggestions of the representatives of the city administration and engineering services were taken into account, meaning the work was of a collegiate nature

Architectural discourse is constantly evolving, responding to contemporary challenges and striving to find new methodological foundations for design. This article examines the theory of discreteness by Gilbert Simondon as a theoretical tool for reinterpreting historical architectural objects. Although this theory is more often applied to the analysis of modern design processes, it can also be productively applied to the study of historical heritage sites. Problem Statement: Existing approaches to the study of architectural heritage are primarily based on stylistic and morphological analysis, which limits their potential for contemporary interpretation. Therefore, it is necessary to apply modern theory (using Gilbert Simondon’s theory of discreteness as an example) as a tool capable of revealing the hidden processes of form-generation in Art Deco architecture and demonstrating its potential as a dynamic system rather than a static historical style. The purpose of the study is to determine the possibility of applying Gilbert Simondon’s theory of discreteness to deepen the understanding of the architectural expressiveness of historical heritage sites, using Art Deco projects as an example. The research tasks are to identify the relationship between historical methods of architectural expression and new approaches to interpreting architectural form; to analyze historical Art Deco projects using discreteness theory; and to systematize the results of a new architectural interpretation of cultural heritage sites. Results: This article explores and systematizes the diversity of architectural techniques in four projects within a unified style, using methods for analyzing both the overall artistic and figurative plan and geometric, constructed detailing. Each object within a unified stylistic framework has distinct imagery, techniques and design logics. Conclusions: Discreteness theory demonstrates that architectural heritage projects are relevant and open to interpretation. Within the context of a unified style, the integrity of style and the multiplicity of approaches are preserved, demonstrating the duality of this state. The proposed approach to structuring architectural form is alternative to the traditional method. The interaction of geometry and language within the context of style with graphic patterns (vector and raster) is also revealed. By applying natural conditions, architecture begins to utilize the basis of natural, geonic structures.

Problem statement. Historical gymnasiums constitute an important layer of St. Petersburgs architectural heritage, being an integral part of its historical and socially significant infrastructure. The study of the typological features of historical educational institutions provides a theoretical basis for scientific and design rationale for the modernization of such facilities, and also complements the overall picture of the pre-modern construction tradition. This paper attempts to typologize the historical gymnasiums of St. Petersburg based on their volumetric and planning patterns. The study aims to identify the planning and spatial-morphological characteristics of historical gymnasiums in St. Petersburg, analyze the stages of their infrastructure development, and determine their role in the urban fabric. Results. The study examined the construction chronology of the objects, taking into account their interaction with the evolving urban planning situation, and analyzed the layouts of the gymnasiums. It was found that the formation of St. Petersburg gymnasium infrastructure included the adaptation of existing buildings before the principles for specialized school construction were formulated. The analysis of the volumetric and planning patterns allowed for the differentiation of the entire array of St. Petersburg gymnasiums into four groups, with the exception of one instance that did not fit into the general typology. It should be noted that the evolution of the studied design solutions reflected the perception of gymnasiums as significant civil facilities. As part of the research, it was important to refer to the legal documents that determined the development of school construction. Conclusions. By the end of the 19th century, St. Petersburg was dominated by high-quality gymnasium architecture, which was largely in line with modern ideas about specialized school spaces. The buildings from this era have significant potential to support educational functions.

The relevance of research. The diagrammatic method of calculating structures, based on the introduction of real deformation diagrams of the materials used, allows for the most accurate description of the stress-strain state of reinforced concrete under various types of force effects. This method involves the use of curvilinear graphs of concrete deformation, as well as nonlinear diagrams of reinforcement deformation with or without a yield point. In this case, force loading under heating conditions significantly changes the initial deformation diagrams of the material, which must be taken into account in their analytical modeling. The purpose of the article is to provide a way to transform diagrams of concrete deformation under loading under normal environmental conditions into diagrams taking into account heating and humidification. The research objectives include a description of the initial characteristics of diagrams under heating conditions and the proposal of a mathematical apparatus for theoretical modeling of diagrams. The results of the study. The nature of the influence of various heating modes on the compression and tension diagrams of B50 class concrete was revealed. The initial characteristics for constructing diagrams are adopted in accordance with the normative literature. Conclusions. The proposed method for accounting for temperature conditions was developed with the possibility of integrating it into a diagrammatic calculation method for concrete and reinforced concrete structures. This method is the most accurate in modern design practice, making this study significant for the construction industry.

Problem statement. To reduce harmful gaseous emissions into the atmosphere, open treatment facilities are protected with covers. Known settling tank covers are relatively heavy and are subjected to rapid corrosion wear due to design imperfections. The purpose of the work is to analyze the known cover design in the form of a synthesis of a cylindrical and shallow conical shell. The objectives of the study are to select the shape of the middle surface and corrugations of a rational option, as well as to develop a lightweight version of the cover design with increased corrosion resistance and durability. Results. The work notes some known covers, provides an analysis of the design of the settling tank version in the form of a synthesis of a cylindrical and smooth shallow conical shell; a new structural design of the cover is described, eliminating the noted disadvantages. Conclusions. The new version of the cover has an architecturally expressive shape, provides maximum load-bearing capacity with minimum weight of the structure, and has high durability. It is recommended to use the development when designing new settling tank covers.

Problem statement. Modern structures operating in various environments perceive vibration loads. Almost no attention is paid to studies of the effect of vibration on corrosion. The purpose of the work is to assess the influence of vibration on corrosive wear. The objectives of the study are to carry out experimental studies on the phenomenon of corrosion under vibration loads, to process experimental data based on the experimental-and-theoretical method and to adjust the model of changing the thickness of the passivation layer. Results. The study provides information on the kinetics of processes occurring on the metal surface and on the model of change in the passivation layer depending on mechanical deformations. The results of studies of vibration influence on corrosion in an aquatic environment are presented. A model is proposed for changing the thickness of the passivation layer of a thin-walled structural element located in an aquatic environment in the presence of vibration. It is established that the presence of vibration loads increases corrosion wear. The need to take into account the obtained data when designing and operating steel structures is noted.

Problem statement. The development of the construction industry and increasing demands on the functionality of buildings and structures necessitate the development of effective methods for strengthening load-bearing structures. The need for reinforcement may be driven by such factors as changes in the building’s functional purpose, increased loads, degradation of material properties, and the need for repairs after emergency situations. Traditional reinforcement methods (installing casings, extending sections, etc.) often have a number of disadvantages: increased labor intensity, increased structural weight, and interruptions in the facility’s operation. The objective of this work is to develop and analyze a technological solution for strengthening reinforced concrete floors and coverings with composite materials. The tasks of the work are to study this reinforcement technology using external reinforcement systems based on composite materials, to investigate the deformation properties of reinforced structures, and to evaluate the effectiveness of this technology. Results. It has been established that the application of external reinforcement technology based on composite materials significantly increases the load-bearing capacity and improves the operational characteristics of structures. A technological solution is proposed based on strengthening reinforced concrete structures of floors and coverings using carbon strips and carbon fiber reinforced plastic plates. This technology effectively strengthens reinforced concrete floors and coverings with minimal disruption to the structural integrity of the elements, while simultaneously preserving their architectural appearance and reducing construction time. Conclusions. The applied technology for strengthening reinforced concrete floors and coverings, based on external reinforcement of structures with composite materials, has high efficiency while simultaneously ensuring operational reliability, which allows this technology to be recommended for wide application in construction practice.

Problem Statement. Reducing the labor intensity and time required to construct monolithic structures while simultaneously ensuring high quality of finished construction products is the most important area for improving this technology. Traditional rebar reinforcement is a resource-intensive process, and the use of fiber-reinforced concrete requires solving problems related to ensuring the mix uniformity and controlling its properties. The aim of the work is to improve organizational and technological solutions for monolithic fiber-reinforced concrete structures by solving the problems of an integrated approach to material modification and technology control. Results. A three-stage quality control system has been developed and tested, comprising input, operational, and acceptance control. The system’s specificity lies in the regulation of operations for dosing steel fiber and carbon nanotube suspension, two-stage mixing, and monitoring the kinetics of hardening. It has been established that the combined use of steel fiber and nanotubes in the concrete mix composition provides a synergistic effect. It has been experimentally confirmed that the proposed solution ensures a 45% reduction in labor costs by eliminating rebar cage installation operations and reduces the construction cycle duration by twenty-five percent due to the intensification of concrete hardening. Conclusions. The significance of the obtained results for the construction industry lies in the development of an organizational and technological solution ready for practical implementation. Its implementation makes it possible to significantly increase the efficiency of monolithic construction by reducing labor intensity and shortening project timelines while guaranteeing the required physical mechanical characteristics of the fiber-reinforced concrete structures.

Problem statement. Improving the reliability and safety of transport facilities located on the shores of the seas (highways, railways, bridges) largely depends on the effective operation of structures of engineering protection from the hydrodynamic effects of the natural aquatic environment. Reducing the risk of accidents on protective structures is an important task. Since the primary way to ensure the safety of structures in our country is to comply with the requirements of national standards of the Russian Federation and/or codes of practice, risk assessment should be carried out taking into account the availability, relevance and validity of calculation methods and applicable standards. The purpose of the research is to assess the risk of accidents on structures protecting transport structures from erosion by sea waves, in cases where the purpose of the loads is not sufficiently justified, or outdated calculation methods were used and, at the same time, the necessary regulatory and methodological documentation is partially missing. Research objectives: to perform an integrated hazard assessment, an integrated vulnerability assessment and an integrated risk assessment of accidents of hydrodynamic impacts of the natural aquatic environment engineering protection structures, depending on the availability, relevance and validity of calculation methods and applicable norms and standards. The work was performed by quantifying the risk of accidents (integral risk assessment) by obtaining normalization coefficients characterizing the proportion of the most unfavorable situation. Results. The work performs integral assessments of the danger and vulnerability of engineering protection structures of transport facilities from the hydrodynamic effects of the natural aquatic environment. Accident risk coefficients have been obtained for the most severe and least severe accident scenarios at such facilities. Conclusions. It is shown that the lack of relevant and reasonable calculation methods and applicable standards leads to a significant increase in the risk of accidents on structures of engineering protection of transport facilities from the hydrodynamic effects of the natural aquatic environment, and, consequently, significantly reduces the reliability and safety of transport facilities.

The main problem in the diagnosis of highways is the lack of a methodology for determining the international index of evenness in areas with bridge structures and its correlation with the safety indicator of passage through bridge structures. Deformation joints, vibrations of superstructures and other features of bridges lead to an overestimation of the values of the evenness index, and, as a result, to an overspending of budget funds for repairs allocated depending on the measurement results. The purpose of the work is to study the peculiarities of the influence of bridge structures on the evenness index and to find approaches to determining the mathematical dependence of the safety indicator for bridge structures on the evenness index. The main objectives of the study are to develop basic models of single artificial bumps; to conduct road laboratory tests on control sections with the placement of artificial bumps and the measurement of evenness, to process experimental data and to evaluate the effect of the size and number of single artificial bumps on the evenness index. The paper presents the results of studies of the effect of single artificial bumps on the evenness index on road sections with and without bridge structures. The significance of the work lies in the fact that the results of experimental and computational studies are the basis for the development of a mathematical model of the dependence of the safety index of passage on bridges on the evenness index, which in turn will optimize the cost of repair and maintenance of highways without compromising the safety of passage on bridge structures.

Russia needs its own methodology for the qualitative assessment of movement by various kinds of transport: private car, truck, public transport, means of individual mobility or on foot. For a qualitative assessment, it is proposed to use the level of convenience of movement as an indicator, which characterizes the traffic conditions on the road network, taking into account the users point of view. Each movement indicator should be expressed quantitatively and qualitatively, that is, have certain significance for the user. With the help of statistical data processing and a sociological survey, the weighting coefficients of the significance of each indicator during movement were obtained. The aim of the work is to develop a methodology for assessing the quality of transport infrastructure services for drivers of vehicles or users of public land passenger transport according to selected indicators for various traffic conditions in localities that differ in size. The objectives of the study are to select indicators for assessing the quality of transport services, determine the weighting values of the indicators taken into account using mathematical statistics for traffic conditions in settlements of different sizes, and form a system of estimates based on the weighting coefficient within the framework of a sociological survey of vehicle drivers. The results of the study made it possible to statistically substantiate the importance of qualitative indicators of traffic on the road network for users of public transport in cities. Conclusions. The significance of each indicator characterizing the users movement on public transport is expressed in mathematical terms. The obtained weighting coefficients of the indicators can be used in the development of a methodology for assessing the level of convenience of movement.

Problem statement. Selection of bitumen binder according to the Performance Grade system plays a key role in ensuring the durability and reliability of road surfaces and foundations. However, this process remains labor-intensive, as it requires taking into account a large array of initial data: climatic conditions, transport loads, features of the designed structure and regulatory requirements. Performing calculations manually takes a significant amount of time, increases the likelihood of errors and complicates the selection of the optimal binder grade. Therefore, an urgent task is to automate the process of selecting a bitumen grade. In this regard, the goal of the work was set, which is to develop a program for the automated selection of a bitumen binder grade taking into account climatic conditions and transport loads. The tasks of the work are to collect initial data for the selection of PG bitumen binder, assess the temperature conditions of the regions of the Russian Federation, analyze transport loads, develop a code and create software for selecting a binder grade according to the PG system, as well as a comparative analysis of the results of selecting the developed software with existing analogues. Results. The developed program provides a significant reduction in labor costs (20-70 times compared to manual calculations), full compliance with the regulatory documentation methodology, and surpasses existing analogues in terms of the relevance of the regulatory framework and the volume of climate data. Conclusions. The significance of the results obtained for the road industry consists in increasing the accuracy of material selection, reducing errors and ensuring the durability of road infrastructure while optimizing the costs of its operation.

Problem statement. As part of the development of small aircraft in the Russian Federation, it is necessary to solve such a problem as the construction of airfield sites that ensure safe take-off and landing, while taking into account the all-season nature of their operation. This problem is especially acute in regions far from the central part of Russia. One of the relevant areas of solving this problem is the use of modification in airfield construction, when strengthening local soils. The purpose of the study is to determine the possibility of using ash and slag waste (fly ash) from thermal power plants of the Siberian Federal District in the construction of cement-based coatings of airfield sites. To achieve this the following tasks are solved: determining the effect of the quantitative and qualitative composition of cement-based mixtures with fly ash additives sealed with aqueous solutions of polyvinyl alcohol on strength and frost resistance; justification of the use of fly ash from thermal power plants in the Siberian Federal District as part of cement-based mixtures sealed with polyvinyl alcohol solutions of various concentrations during the construction of airfield site coverings. Results. The rationale for the use of fly ash from thermal power plants in the Siberian Federal District as part of cement-based mixtures sealed with solutions of polyvinyl alcohol of various concentrations is presented. The study found that the introduction of fly ash into the cement-based mixture provides an increase in strength while reducing the level of water absorption, uniform distribution of a film-forming solution of polyvinyl alcohol over the volume of the mixture, and also increases the density and frost resistance of cement-based soils. Strengthening of clay soils of cements modified with solutions of polyvinyl alcohol together with fly ash can be used in the construction of airfield sites. Conclusions. The significance of the results obtained for the construction of transport facilities lies in the fact that strengthening clay soils with cement and modifying them with solutions of polyvinyl alcohol together with fly ash from the Siberian Federal District can be used in the construction of airfield sites. The use of fly ash in the composition of cement-based mixtures provides the possibility of obtaining an economic effect, which consists in reducing the cost of building airfield sites compared with technology based on the use of stone materials.

Problem statement. The construction of highways in remote territories of the Russian Federation requires the import of a huge amount of stone materials, which increases its cost. In these areas, as a rule, cement-reinforced soils are used in the construction of road pavement. The problem of using road pavement with layers of cement-reinforced soils is represented by their gradual destruction due to variable freezing and thawing. One of the ways to increase the durability of such layers of road pavement is to improve the properties of their constituent road-building materials. The aim of the work is to increase the frost resistance of cement-soil layers of highways pavement by adding modifying additives that will reduce or eliminate the negative effect of water on the aggregates of the cement-soil matrix while maintaining the achieved strength. To achieve this goal, the following tasks were formulated: to identify the effect of the Portland cement content on the physical and mechanical properties of cement-soils sealed with polyvinyl alcohol solutions of various concentrations; to conduct a pilot test of the research results during the construction of experimental sections of the highway bypassing Volgograd. Results. To increase the frost resistance of the layers of road pavement, the formulation of a modified cement-soil mixture has been determined. It has been experimentally established that the introduction of cement into the soil together with polyvinyl alcohol as mixing water reduces the water-solid ratio due to plasticization. An increase in the concentration of polyvinyl alcohol in the solution with a simultaneous increase in the amount of cement contributed to an increase in strength and frost resistance coefficient for all the samples studied. Two experimental sections have been built on the bypass of Volgograd with the use of M400 and M500 cements with the sealing of a cement-based mixture with an 8% solution of polyvinyl alcohol. The condition of the experimental sections after two years of operation is assessed as satisfactory. Conclusions. The significance of the results obtained for road construction is to confirm the possibility of using polyvinyl alcohol solutions in a cement-soil mixture in the construction of road pavements, which will increase the efficiency of highway construction in remote territories of the Russian Federation.