It is well known that imperfections are always present in structural elements. Imperfections can significantly affect the behavior and bearing capacity of steel structures, especially in the case of stability-related tasks. Therefore, inconsistencies must be taken into account in the load[1]bearing capacity model and their correct application (setting the shape and value) is a key point in the numerical analysis process. In recent decades, much attention has been paid in the domestic scientific space to updating imperfection models for use in numerical models, including taking into account modern more accurate manufacturing and installation technologies for steel structures. The purpose of this study is an analytical review and analysis of scientific research and technical literature, followed by synthesis and elaboration of recommendations on imperfections in relation to the calculation of steel structures using computer modeling technology, including the finite element method. The results of the study contain instructions on how to set the shapes and values of imperfections for different groups of imperfections. The article consists of two parts. The first part is devoted to the study of geometric imperfections, residual stresses and rules for the combination of imperfections, the second part of the article is devoted to equivalent imperfections.

The object of the study is reinforced concrete modules used for high-speed construction of low-, medium- and multi-storey buildings and structures for various purposes. The subject of the study is the forces in the nodes of slinging of reinforced concrete modules. A sample with the distribution of forces of five hundred modules is taken to analyze the nature of force distribution, It’s sample is realized according to the patented technology of Group of companies “MonArch”. The sample was analyzed by the Brandon’s method. Analytical determination of forces in slinging node0s of the selected module was carried out by approximate method – by cargo areas. The character of the actual distribution of forces is conditioned by the sling length obtained as a result of the slinger’s adjustment, as well as by the difference between the tempering and design strength of concrete of the module load-bearing structures. According to the results of the calculation it was obtained that the most loaded are the corner nodes of slinging. Properly selected and adjusted length of slings allows to distribute forces more evenly over the structure and avoid overstressing of individual structural elements of the module.

The results of experimental studies of the force interaction of models of free-standing foundations with a sandy base under rapid additional loading are presented. The studies were carried out on reinforced concrete foundation models and a metal stamp in a sand tray. The analysis touched upon such factors of the operation of the “foundation-soil” system in the presence of rapid additional loading as a change in the bearing capacity of the foundation for bending, foundation settlement, transformation of the diagram of normal contact stresses. The reasons for the decrease in the bearing capacity of foundations for bending during rapid additional loading have been identified, the main one of which is a change in the shape of the diagram of normal contact stresses. Factors influencing the concentration of normal contact stresses near the edge zones of the foundation base have been identified, including: different rates of components of the stress redistribution process in the foundation, the development of dilation, etc.

 The problem of robustness of structural systems of buildings and structures is receiving more and more attention in the publications of Russian and foreign authors. In this regard, the presented review article is aimed at systematizing, summarizing and analyzing new research results on issues related to the development of calculation models of static, dynamic and static-dynamic resistance of buildings structural systems under conditions of special and emergency impacts, as well as criteria, used when testing their robustness in special design situations, seems relevant. To achieve this goal, a critical review and analysis of foreign and domestic publications is provided on the issues of formulation and conceptual approaches to assessing the mechanical safety of buildings and structures at the stages of the life cycle of buildings and in emergency situations, force and environmental resistance factors of buildings structural systems under dynamic loads in emergency situations as well as calculation models of the resistance of load-bearing.

Particular attention in the scientific review is paid to the analysis of works related to assessing the robustness of buildings structural systems using semi-probability (deterministic), probabilistic methods and risk assessment methods. The main conclusions and possible directions for the development of these studies are formulated in the conclusion of the article.

Statistics on fire incidents in the Russian Federation indicate that a number of regions with high seismic activity have the highest number of fires in the country. This poses a risk of building collapses due to seismic loads on vertical load-bearing structures damaged by fire. The current normative approach to the calculation of fire safety of reinforced concrete structures does not consider heat and mass transfer at the stage following the termination of the fire. The distribution of temperature fields along the cross-section of a reinforced concrete column is analyzed, taking into account the stages of heating and cooling. Standard fire tests of experimental reinforced concrete specimens are performed. The duration of standard fire exposure is 15, 30 and 45 minutes. For the central areas of the cross[1]section, the highest temperatures were obtained after heating, with a temperature increase of up to 222%. To elucidate the distribution of temperature fields, a numerical heat-technical FE calculation of experimental specimens in SOLIDWORKS PC is conducted. Based on the experimental data on thermocouples, the thermal characteristics λ and C are specified for each sample. ts of the study indicate that in order to identify the maximum temperatures, it is necessary to consider both the heating and cooling stages.

The relevance of the study is determined by the presence of a complex of socio-economic, environmental, cultural and historical problems in urban planning related to the effective use of former industrial areas and the creation of public spaces with the preservation of architectural monuments. The article examines the problems of renovation of historical buildings and industrial architecture in large cities. The subject of the study is the renovation of a cultural heritage site of regional significance (ensemble) “Distillery” in Kursk.

The study of the problem of using industrial facilities that have cultural and historical value is interdisciplinary in nature and makes it possible to reveal the urban planning potential of industrial architecture buildings. The principles of choosing directions and assessing the results of renovation depending on the size of the object and its place in the structure of the city remain insufficiently studied. The authors propose the use of immersive practices as the most promising direction for renovation. The return of abandoned and problematic urban areas for new intended uses can be carried out in various ways. The principle of creating an immersive space is based on a deep understanding of the historical, cultural and environmental significance of the object, maintaining a balance between the original appearance and the urban surroundings. Immersive technologies have been successfully implemented in the urban environment of European and Russian cities. The authors reveal the characteristics of the immersive space and propose an option for using the territory of the distillery based on a plot immersion in the cultural matrix of the object using virtual reality technologies. The realism and dynamism of the space, along with maximum preservation of the appearance of the cultural heritage site, allows us to rethink the transformation of industrial areas and their significance in the modern urban environment in a new way

Methods of modeling are considered with the division of methods and models into two classes: mental and material. The dependence of the application of certain modeling methods and types of models on the nature of the object or phenomenon under study is determined. It has been established that an integrated and systematic approach is used for complex objects. The inefficiency of technical, economic and "complex" research methods is shown, and it is concluded that a way out of the current situation is possible only if the architects revise the existing methodological concept. An analysis of the criteria that an architectural object must meet for quantitative analysis and modeling of its structure is proposed.

It is shown that designers and researchers use methods of quantitative analysis of the functional and spatial structure of the landscape and recreational space of the urban environment, as well as additional methods and techniques for analyzing the functional and spatial structure of the urban environment. The only realistically feasible way of successful construction and management of the life of demoecosystems as an object of architecture is the development of functional models that are adequate to real ecological systems of the "population-environment↔" type with an accuracy of "C-isomorphism" (system isomorphism). Thus, the formulation of the concept of the project for the reconstruction of landscape and recreational space is based on the understanding of space as a demoecosystem, the achievement of efficiency, the interrelated work of all components and ongoing processes (industrial, domestic, recreational and communication). Thus, the integrity of the landscape and recreational space is achieved.

Numerous studies have shown that control and stabilization of drying, in which the amount of moisture is removed within 70%, in ceramic products is mainly due to the introduction of various absorbers into clay compositions, which increase the intermolecular distance between clay particles, as a result of which mechanically mixed water is removed. The purpose of the work: to study the effect of ash and slag mixture on drying indicators: plumbing, shrinkage and mechanical strength of a ceramic sample based on technogenic raw materials of non-ferrous metallurgy - GZI (clay part of the "tails" of gravity of zircon-ilmenite ores) using a regressive analysis method.

Task statement. Given the limited availability of high-quality raw materials in many regions of Russia, energy waste and non-ferrous metallurgy without the use of natural traditional raw materials were used to obtain ceramic samples. The inclusion of a non-shrinkable ash-slag mixture in the ceramic composition contributes to a more uniform distribution of moisture throughout the sample and then to its smooth removal during drying of the article. The ash and slag mixture must be added to the ceramic masses to reduce shrinkage during drying, increase moisture conductivity, but it must be borne in mind that the compression strength of the dried sample decreases. Increase of ash-slag mixture content in ceramic compositions reduces its plasticity. Increasing the content of ash and slag mixture to 32% reduces ductility to 9. Such plasticity in the formation of semi-finished products contributes to the appearance of cracks on them (the binding ability of the clay component decreases, which does not allow forming samples without defects). Optimal compositions for efficient drying of samples are those containing 20-24% ash and slag mixture. In this work, a regression analysis method was used, which makes it possible to select the necessary model equations that will help determine ceramic masses with effective properties and to predict results that were not included in the experiment.

Foam glass and foamed glass-ceramic materials have a number of unique properties. They are chemically resistant, light, durable, do not burn, do not transmit heat and sound well, etc. They are used both in private construction and in the construction of specially responsible facilities. The article confirms the possibility of using flask as a raw material for the production of porous glass ceramics (PSK) in one charge heating by powder foaming. Flask, soda ash and corrective additives (chalk, clay) were ground together in a dry state, poured into heat-resistant molds and fired. The temperature ranges of sintering and foaming of the charge based on the flask, the effect of additives on the macrostructure and properties of porous glass ceramics have been established. The results were obtained by thermal analysis (TA), X-ray phase analysis (XFA), etc. Chalk and clay in the composition of the charge have a significant effect on the temperature of its sintering and foaming during heating, as well as the phase composition of the UCS samples. As a result, samples with a finely porous structure in the form of blocks of 500×500×200 mm in size with an average density from 190 kg/m³to 1535 kg/m³, compressive strength from 2 MPa to 116 MPa and with a thermal conductivity coefficient from 0.06 W/m°C to 0.61 W/m°C.

Porous glass ceramics based on flasks, soda ash and corrective additives (chalk, clay) surpass many analogues in terms of physical, mechanical and thermal properties and can be used as structural, thermal insulation and other types of building materials during construction, repair and reconstruction of facilities for various purposes.