Introduction. Modern buildings operate under changing climate and loading conditions, where foundation degradation leads to cracks, uneven precipitation and load-bearing capacity loss. Regular monitoring and inspections enable timely risk detection, accident prevention and repair cost reduction. The aim of the study is to develop methods for assessing operational safety across various foundation conditions, including calculating precipitation and performance limits.

Materials and Methods. The study included visual inspection, structural scheme identification, instrumental diagnostics, building inspection with preparation of the architectural drawings, defect detection and documentation, installation of pits with preparation of measuring drawings of еру foundations for open pits and identification of the strength characteristics of the foundation material, opening structures and testing building materials to identify their strength characteristics with subsequent verification calculations of the load-bearing elements.

Research Results. Based on the results of the verification calculations and identified structural defects, the condition of the building elements and the building as a whole has been established. Recommendations have been developed for ensuring the normal operation of a building as well as for strengthening or repairing structures.

Discussion and Conclusion. Comprehensive technical inspection of the building using advanced non-destructive testing methods and verification calculations revealed the current technical condition of the foundation elements and foundations. Based on the results of the technical inspection, taking into account the results of the verification calculations, it can be concluded that for further normal operation of a building in some areas, it is necessary to take measures in order to strengthen the foundations or strengthen foundations soils. The scientific significance lies in the developed and testing of the methodology for comprehensive assessment of the load-bearing capacity of foundations taking into account realworld operating conditions, which makes it possible to increase the accuracy of forecasting the durability of buildings on weak soils. The practical value of the results lies in the formation of specific recommendations for strengthening foundations. The findings can be used in inspecting similar civil and industrial facilities. 

Introduction. The study is dedicated to developing a new method for identifying defects in building structures with stress concentrators. The method is based on the integration of shadow ultrasonic testing with deep learning algorithms, which would enable accurate diagnosis with reliably identifying the geometric characteristics of defects.

Materials and Methods. A finite element model of an area with an angular point and damping layers made of metal with a flexible coating was used. An ultrasonic actuator and receiver were placed on the opposite edges. Numerical experiments with changes in the geometry and materials of the area and defect parameters were conducted on a distributed computing system. The resulting signals were converted into spectrograms which were used in order to train a convolutional neural network that establishes a connection between the spectrogram and the defect parameters.

Results. An extensive dataset of spectrograms has been formed. The trained neural network has displayed the ability to accurately identify the key defect parameters based on a spectrogram such as size, position, and orientation. Verification of the method has shown that it outperforms the traditional methods of ultrasonic signal analysis in terms of its accuracy and speed.

Discussion and Conclusion. The hybrid approach for non-destructive testing in complex geometric conditions has been proven to be effective. The major advantage is automated and intelligent data analysis reducing a degree of subjectivity. The practical significance is the creation of a prototype adaptive diagnostic system. Prospects are related to further training on experimental data and integration into portable systems for monitoring structures. 

Introduction. The compressive strength of masonry is the most important mechanical characteristic assessed during inspections of buildings and is determined based on direct testing of bricks and mortar selected from the walls. However, current regulatory documents also recommend the use of non-destructive testing methods, particularly while examining cultural heritage buildings. However, non-destructive methods fail to take into account differences in the strength of bricks and mortar joints in the surface layers and their main volume, interaction of bricks and mortar, as well as anisotropy of the mechanical characteristics of masonry. The article presents the results of a study of the anisotropy of the compressive strength of ceramic bricks and an analysis of its influence on the results of assessing the strength of masonry using indirect methods.

Materials and Methods. The object of the research are two types of bricks: historical bricks from the walls of the barracks of the Brest Fortress built in 1933, as well as modern bricks produced in the Republic of Belarus. The strength of the brick was identified under a compressive load in the direction of the front, support and end surfaces on cubes with an edge size equal to the height of the brick.

Research Results. Graphs of the ratio between the obtained strength values of experimental cube samples under compression perpendicular to the front and end surfaces of the brick to the compressive strength perpendicular to its supporting surface are presented. Similar studies by other authors, including on ceramic cylinder samples, are analyzed. It was found that the compressive strength of the historical bricks perpendicular to its front and end surfaces was higher than their compressive strength perpendicular to the supporting surface. The opposite pattern was observed for modern bricks. However, due to the high variation of the results, it is not possible to establish a correlation between the compressive strength and the direction of the compressive force.

Discussion and Conclusion. The results of some studies that have shown that ceramic bricks are an anisotropic material are presented. A possibility of using non-destructive testing methods for brick strength has been evaluated, as well as that of designing a calibration ratio linking the compressive strength of a brick with the results of indirect testing of the front surface. 

Introduction. The article looks at the issue of determining the design lengths of rods of the structural construction of the Kislovodsk type. While examining the existing structure of the coating of the shopping center, in the design documentation for the object, the authors found that the design length coefficient equal to 0.8 was used in the calculations of the rod structure. The value of 0.8 is due to the results of the tests performed at Kucherenko Central Research Institute in 1987. However, according to the current regulations, a coefficient of design length equal to one is to be used. The aim of the article is to justify the value of the design length coefficient in calculations of such structures.

Materials and Methods. A standard unit of attaching rods to a nodal connector is considered. It was decided to study the work of both a separate structural unit and rods together by modeling in the Femap with Nastran software package. The paper considers the effect of a nodal joint on the stability of an individual rod. To this end, a nodal structural element with a support at the contact connection of a compressed rod and a calculation of a separate rod for stability was modelled. A system of rods is then considered in order to determine the critical force, taking into account the influence of adjoining elements. The scheme consists of four rods of the lower belt and four rods of the braces connected in one node and loaded with a compressive or tensile load.

Research Results. The considered separate joint of the rod with the connector, where compressive forces are transmitted through a tight contact, is very close to rigid fastening by the nature of the work when checking the stability of the rod. The design length coefficient for compressed elements ranges from 0.77 to 0.88, depending on the force values in the elements and their cross sections. Based on this, it can be unambiguously concluded that the application of a coefficient of 0.8 for all compressed rods cannot be theoretically justified.

Discussion and Сonclusion. The coating studies show that the requirements of SP 16.13330.2011 "Steel Structures" are correctly applied in terms of determining the design length of a compressed rod equal to 1, and the use of a coefficient equal to 0.8 cannot be theoretically justified. Reducing the metal consumption while using reduced design length coefficients in calculations does not lead to significant savings for the overall structure and is not feasible. 

Introduction. This study is dedicated to development of methodological foundations of territorial development construction project (TDCP) as a tool for managing integrated territorial development (ITD). The existing approaches to construction organization based on the traditional object-by-object construction organization project (COP) fail to provide necessary coordination of resources and logistics. The aim of the study is to develop the theoretical foundations and structure of TDCP and structure of ITD, ensuring effective management of construction processes within the framework of ITD projects and master plans.

Materials and Methods. The research is based on the analysis of theoretical approaches to construction organization, systematization of experience in implementing integrated territorial development projects and identification of the drawbacks of the existing methodologies. Methods of system analysis, comparative analysis, structural and functional modeling and generalization of the theoretical provisions were used.

Research Results. The structure of TDCP has been developed, including the external contour (transport accessibility, engineering infrastructure, engineering protection of a territory, logistics links, natural and territorial conditions, institutional environment) and an internal contour (production facilities, temporary infrastructure, internal engineering networks, transport networks, labor resources, stages of construction). The mechanism of converting the constraints of the external contour into the internal one and compensatory measures ensuring the sustainability of the project is substantiated.

Discussion and Conclusion. The developed TDCP methodology serves as the theoretical foundation for organizing construction within integrated territorial development projects. The introduction of the concept of external and internal contours enables one to systematically account for the limitations and capabilities of a territory, ensuring efficient allocation of resources and coordination of construction processes. 

Introduction. Well-known studies on the research subject have failed to specify sample sizes and types of workshops based on their technological characteristics, which prevents us from summarizing the numerous damage data. The downside of the previous studies is the lack of generalizations with designing regression dependences of damage to the bearing elements of buildings on their service life. The subject of the study is the correlation of damage to the main structures of industrial buildings from their service life. In order to design these dependencies, a significant sample of workshops  (at least 100 workshops) has been investigated and the frequency of damage to their main structures has been examined. The frequency of damage has been previously studied and published by the authors. The aim of the study is to establish correlations between the degree of damage and the service life of structures.

Materials and Methods. The objects of the study were single-storey industrial buildings of the metallurgical, machine-building, energy industries, as well as production of building materials. The workshops were inspected by means of the standard methods endorsed in the national standards and norms. In order to analyze defects and damages, an electronic database was designed in a tabular processor that recorded all the basic information on types of workshops, materials and structures, defects and damages.

Research Results. The analysis of data on a large sample of industrial buildings made it possible to establish correlations between damage and the service life of structures. It was found that the rate of damage to steel columns is higher than that of reinforced concrete columns. The intensity of damage to steel columns is described by means of an exponential dependence, while that of reinforced concrete columns is a linear one. Brick and reinforced concrete walls are damaged linearly depending on the service life. The dependence "damage - service life" of reinforced concrete floors and coatings is approximated by a polynomial of the second degree, close to a linear relationship. Similar linear damage is typical of steel trusses. The damage rate of steel crane beams does not directly depend on the service life of the building itself, as the beams are replaced if damaged.

Discussion and Conclusion. As a result of the study of the frequency of damage, mathematical models of "damage - service life" of industrial building structures were obtained that can be used in order to optimize maintenance and repairs of buildings. The distinctive features of the accumulation of damages and defects over time for metal frames of industrial buildings associated with human mistakes are noted. In order to reduce accidents and optimize costs throughout the life cycle of buildings, it is suggested that a risk-based approach is applied, the likelihood of errors and cost of restoration measures at the stages of design, construction and operation are assessed.   

Introduction. Using the example of the production of road concrete in the Rostov region, the article looks at the issues of increasing the efficiency of the technology for preparation of concrete mixtures to ensure the normative indicators of the physical and mechanical properties of concrete without increasing cement consumption and additional costs for reconstruction of existing enterprises in the construction industry. The aim of the study is to develop a set of prescription and technological measures to ensure regulatory requirements for strength characteristics of concrete produced with the use of local raw materials with no technical re-equipment of existing concrete mixing plants.

Materials and Methods. To this end, while conducting the experimental research, a local raw material base was used that is widely available in the construction industry. The study aimed at developing prescription and technological measures for improving the production efficiency of the road concrete under study was performed using standard methods for assessing the normalized properties of similar materials, concrete mixtures and hardened concrete. In order to optimize the parameters of the developed formulation and technological solutions, mathematical modeling methods of the stochastic system under study based on the theory of experimental planning were applied.

Research Results. The developed innovative technology for preparing concrete mixtures enables an increase in the strength of the concrete under study by 15–20%, or reduce cement consumption by 10–12% without a reduction in the strength of the resulting material. The results were achieved by means of developing a set of prescription and technological measures including introduction of the suggested carbonate micronutrient and polycarboxylate superplasticizer into the concrete mixture in combination with the developed two-stage method for preparing the concrete mixture.

Discussion and Conclusion. The novelty of the developed technology for preparing concrete mixtures is protected by an invention patent. The results were achieved by means of the combined introduction of the developed limestone-shell filler and superplasticizer ST 5.0 into the concrete mixture in combination with an innovative two-stage technology for preparing concrete mixtures. Based on the general theoretical understanding of the structure formation of cement concretes as well as of their strength properties, it is possible to extend the results of these studies to production of a broad range of monolithic and prefabricated products as well as structures that are to comply with the regulatory requirements for not only compressive strength, but also for tensile strength. Naturally, in each specific case, additional research will be required that would take into consideration the specifics of the regional raw material base as well as the specifics of a particular enterprise in the construction industry and its product range. 

Introduction. The research is devoted to developing effective methods for managing construction waste on residential sites in dense urban areas. Innovative approaches to waste management are set forth, including separate collection, digitalization of processes and modern primary treatment technologies in compliance with the requirements of ecology and resource conservation.

Materials and Methods. The study was conducted using the method of aggregated calculations of waste volume using the example of an actual housing construction facility with an area of 20,000 m2 . The assessment was performed based on the distribution of waste by categories and stages of production (excavation, monolith, installation, engineering networks, finishing, landscaping). The average coefficients of waste generation and material density were used in oder to calculate the total mass of each fraction. A comparative analysis of two logistics scenarios was carried out: a traditional one (collecting all waste together and sending it to the landfill) and an innovative one (separate collection, on-site pretreatment, recycling priority and digital accounting).

Research Results. The significant economic and environmental effect of the introduction of an innovative approach to construction waste management is indicated. Compared to the basic scenario ("mixed collection → landfill"), the innovative scheme ("separate collection + on-site processing + recycling priority + digital registration") provides a 51% reduction in landfill volumes and a 50% reduction in traffic. The major success parameter is the volume of soil reuse, which reduces the mass of recyclable waste and the number of dump truck trips by almost a half. The financial benefit is complemented by the possibility of commercial sales of secondary resources and introducing digital control tools. The results are presented in tables displaying the monthly dynamics of waste generation. Recommendations on containerization and assessment of the impact of the assumptions on the final indicators are provided.

Discussion and Conclusion. A construction waste management methodology has been developed that reduces the volume of disposal, transport load and provides savings by optimizing on-site recycling. An increase in the level of secondary use and effective primary waste treatment has been ensured. 

Introduction. The article examines the development of urban irrigation in Central Asia as regards the evolution of the urban environment structure. Agricultural irrigation and the history of Central Asian urban planning have been extensively investigated, while urban irrigation has not been sufficiently studied. There are barely any studies looking at landscape irrigation in the chronological context of urban development for the region. Therefore the aim of the study is to identify the stages of development of urban irrigation and irrigated elements of the urban environment as well as the boundaries and characteristic features of each stage in the historical context.

Materials and Methods. The stages of urban irrigation development were identified by analyzing historical and archaeological materials as well as studies on landscape architecture, urban planning, and hydraulic engineering throughout a variety of historical periods.

Research Results. As a result, the stages of development of irrigation and the irrigated urban environment have been identified and described; a chronographic line of irrigation development has been designed; irrigation schemes of cities throughout various historical periods have been designed.

Discussion and Conclusion. The results can be used in order to substantiate the cultural and historical value of the openchannel irrigation in modern cities of Central Asia, as well as to design adaptation measures for cities whose climates are becoming arid. 

Introduction. An urgent task facing the field of road maintenance is an objective assessment of their residual resource. The existing methods are typically subjective or require that complex procedures are carried out. The aim of the study is to develop a new approach to such an assessment based on instrumental measurements.

Materials and Methods. The object of the study is road surfacing of highways. The method is based on a model that relates the amount of elastic deflection of the coating to the estimated number of loading cycles until the strength has been exhausted. Deflection was measured using a Falling Weight Deflectometer. The technique allows one to adapt the model to a variety of conditions by calibrating the coefficients.

Research Results. Based on the suggested model, a four-level scale of the condition of the road surface has been designed according to the size of the residual resource: a normative, satisfactory, pre-maintenance and critical one. In order to increase the reliability of the estimate, the median value of the resource is used as the calculated value for the measuring point, and its weighted average value is used to characterize the entire site.

Discussion and Conclusion. The developed approach makes it possible to quantify the residual resource based on instrumental data. Implementing this technique would increase the objectivity of diagnostics and assist optimal repair planning. The prospects of the study are related to the further adaptation of the model for a variety of road and weather conditions. 

Introduction. The relevance of using applying air-source heat pumps (ASHPs) in Russia’s moderately cold climate conditions is restrained by a sharp decline in their efficiency at low outdoor air temperatures. The aim of this study is to present a digital approach to lifecycle management of low-rise capital construction facilities based on a combined heat pump system with optimized heat and air exchange.

Materials and Methods. A technical solution is set forth incorporating a patented mixing chamber installed in the boiler room to supply an air mixture with a calculated temperature gradient to the ASHP evaporator. The system is integrated with a cross-stream supply and exhaust ventilation (efficiency of 40–60%) and controlled by a digital module based on a microprocessor and PWM regulator. Mathematical modeling of streams was performed using the Bernoulli and continuity equations. For monitoring and automatic control, a set of temperature and pressure sensors was employed to ensure adaptive operation of the compressor, fans, and backup electric boiler.

Research Results. Experimental data have confirmed that the joint operation of the ASHPs with a heat recuperator and mixing chamber allows maintaining a high coefficient of performance (COP) of the system. It was found that the threshold of economic feasibility remains at an outdoor air temperatures of down to –15°C and heat carrier temperatures of +30…+45 °C. The developed digital control algorithm optimizes the ratio of outdoor to recirculating air minimizing heat losses and electrical loads.

Discussion and Conclusion. Implementation of the suggested digital modular and functional control scheme ensures rational heat and air exchange, reduces the size and cost of engineering utilities, and enhances the energy efficiency of low-rise buildings. The developed solution can be scaled for a broad range of climatic conditions nationwide contributing to resource conservation and extension of the lifecycle of capital construction facilities.