Introduction. Successive development of historically established urban structures, formation activity areas of citizens with special attention to the image perception and quality of urban environment are becoming a steady trend. The research purpose is to propose a concept for the urban environment transformation, development of public spaces and cultural contexts based on study and systematization of works on citizens’ perception and city image formation.

Materials and methods. The research is based on the examination and systematization of works in culture, literature, psychology, sociology, architecture studies devoted to the perception of citizens, identifying city image and its elements, and mental maps making. The parallel formation the district volumetric-planning structure and urban environment image perceived by local residents is also traced. Interviewing was conducted and image elements appearance, stages of their development and gradual incorporation into the urban tissue were identified. Scientific novelty is that in addition to the territory historical and genetic analysis, the computer and Data-Base resources were involved to reach the objectives. Basing on archival maps, historical photographic material (postvu.com) and descriptions examination, popular and visited places are identified; heat maps of the frequency of recognizable places occurrence are drawn up and the areas of visual activity are defined.

Results. A way of monitoring the existence of urban environment and perception is proposed, and trends of ongoing transformations are identified. It is defined that the areas of visual activity are mainly grouped along historically formed pedestrian routes (streets, squares with well-formed image); within the group, stable connections are established between the areas; between groups of areas separated by large distances, there are image gaps, but correspondences related to their semantic content are also established.

Conclusions. A concept developed in the work is implementing the principles and techniques of structuring gaps and “visual voids” not perceived by people in order to saturate them with imaginative elements. The elements composing the image need to be completed and fragmentarily restore. Public spaces should be united, behavioral scenarios should be arranged and pedestrian routes should be organized, promoting the city image creation and the self-identification of citizens.

Introduction. The article is focused on the modern criteria of the university campus’s architectural and spatial organization. The authors identify some campuses typologies. Using this information, they analyze Novosibirsk higher educational institutions and their placement features in the city’s structure. Finally proposed classification, based on functional saturation and technological features, reflects the types of existing campuses in Novosibirsk. The result of this analysis in a conclusion whether the territorial organization of Novosibirsk universities meets the modern requirements of the campus.

Materials and methods. Based on the study of electronic, written and literary sources, various variants of the typology of university campuses are analyzed. Generalization and comparison of data on the constituent universities was carried out on the basis of comparative analysis. The conceptual modeling reflects the architectural and spatial features of the placement of university campuses, as well as their functional saturation.

Results. Territorial typological features of the location of campuses in the structure of cities are revealed. On the example of university campuses in the city of Novosibirsk, their spatial organization is indicated. In order to determine the features of the technological organization of Novosibirsk universities, a comparative analysis of the functional components of the university was carried out and a conceptual campus model relevant for Novosibirsk universities was presented.

Conclusions. Based on this analysis, it is concluded whether the territorial organization of Novosibirsk universities meets the modern requirements of the campus.

Introduction. The consequences of destructive earthquakes show that the problem of analyzing the response of reinforced concrete frames under seismic loads after a fire is urgent. The calculation models applied in this case for individual elements and buildings as a whole should take into account the nonlinear properties of concrete and reinforcement. The low-cycle nature of seismic action leads to the necessity of developing hysteresis models, which would reflect the specific behaviour of the structure not only during loading but also during unloading and subsequent application of force in the opposite direction. A brief review of hysteresis models for reinforced concrete elements under low-cycle loading with emphasis on the stiffness properties during unloading is presented. Hysteresis models for reinforced concrete elements after fire have not been developed at present.

Materials and methods. The proposed model is based on a bilinear diagram for the calculation eccentrically compressed reinforced concrete columns damaged by fire. Only three parameters are required to describe the model: limiting moment, limiting curvature, and effective initial stiffness. In determining the unloading stiffness, a method based on direct consideration of the stress and strain distribution in the stress-strain stage corresponding to full unloading is used. The model takes into account different levels of axial loading, indirect reinforcement by transverse clamps, longitudinal bending and non-uniform stress distribution in the compressed zone of concrete.

Results. Based on the proposed model, a comparison of bilinear diagrams of deformation and stiffness at unloading for reinforced concrete columns subjected to standard fire of different duration was carried out. Calculation results showed a significant decrease in the bearing capacity and stiffness of the damaged columns and an increase in their plasticity. The unloading stiffness for reinforced concrete columns was less than the initial one. The decrease in unloading stiffness is the more intensive the longer the fire exposure was.

Conclusions. The obtained model is easy to use and suitable for most engineering calculations. The model can be used as a basis for constructing a hysteresis diagram for low-cycle impacts after a fire, which is necessary for seismic analysis of structures in the time domain.

Introduction. Modelling of pile foundations in modern software packages (PC) is often carried out in a linear formulation of the problem and with the use of coefficients that overestimate the results of pile foundations by several times. This approach leads to significant overconsumption of materials and overestimation of the estimated cost of the object under construction. In modern realities, designers are faced with the problem of modelling the design situation, which is closest to the real operation of the pile in the ground, and since the foundation soil is a heterogeneous medium, the calculation must be carried out non–linearly, which is quite time-consuming in software packages. A numerical comparison of full-scale tests of a single pile under static load and calculation in a software package, taking into account the nonlinearity of the foundation soils, is carried out.

Materials and methods. The calculations are carried out in the finite element software package LIRA-CAD by modelling the design scheme with volumetric finite elements. The change in the settlement of piles in different soils under step load is analyzed.

Results. Numerical experiment of change in the settlement of a single pile using a volumetric finite element model with a given physical nonlinearity of the soil was performed. The obtained results of the numerical experiment are compared with the results of the full-scale experiment.

Conclusions. The results of the study show a large discrepancy between the settlements of piles according to field tests and the results of calculations according to SP 24.13330.2021. With the help of modern software packages, it is possible to carry out more accurate calculations. However, the introduction of correction coefficients can bring the calculated situation according to regulatory documents closer to more real conditions of deformation of the foundation soils in the process of preliminary selection.

Introduction. The adhesion properties and factors influencing the formation of the composition of thermally modified timber (TMT) and cement are investigated. The results were focused on the creation of a new material with improved service properties, which is named thermo-wood concrete (TWC).

Materials and methods. Adapted standard methods to assess the adhesion of sand-cement mortar with TMT and compressive strength of sand-cement mortar obtained on waters infused with different types of wood and TMT were applied. The influence of the following factors was considered: the intensity (classes) of wood thermal modification, wood species, mortar formation method, cement binder content, wood surface conditions and moisture content of TMT, the presence of final steam curing of specimens.

Results. The sand-cement mortar with a high content of cement binder had the highest adhesion with TMT. PVA-emulsion solution resulted in additional slight improvement of the sand-cement mortar and TMT adhesion. In general, unmodified (natural) wood had higher adhesion in comparison with TMT under the same conditions. Negative factors included premoistening of thermally modified timber surface, cleaning and leveling of its surface and the use of coniferous species for TMT specimens. The strength of sand-cement mortar was the lowest for specimens with addition of PVA-emulsion. Factor of water purification after infusion with TMT and unmodified wood had insignificant effect on strength of sand-cement mortar.

Conclusions. TMT-cement composition had a lower adhesive force in comparison with unmodified wood. This is due to
the combined effect of low hygroscopicity and wettability of the TMT surface. Water washing of the TMT is inappropriate due to deterioration of adhesion properties of the filler in TWC. To increase the adhesion of the components, it is recommended to use mortars with a high content of cement binder.

Introduction. Ho Chi Minh City, the largest city in Vietnam, located in the lower reaches of the Saigon – Dong Nai river system, is facing increasingly severe flooding due to changes in river flow and water levels. This article presents the results of a study to assess the impact of hydraulic structures located in the upper reaches on the water level in the lower reaches of the SG – DN river.

Materials and methods. To assess the impact of upstream reservoirs and flood control structures on the water level in the lower reaches of the SG – DN river, hydrological data of the river network were collected and a hydraulic model was developed based on a digital elevation model (DEM) using the software package Mike 11, Mike 21 and Mike Flood.

Results. The water level of the Saigon River from the upper reaches to the Thu Dau Mot measuring station directly depends on the Dau Tieng reservoir, and the Tri An reservoir directly affects the water level in the river section from behind the Tri An dam to the Dong Nai section in the Tam An – Long Phuoc area.

Conclusions. In the sections of the Saigon and Dong Nai Rivers less affected by the two upstream reservoirs, it is necessary to develop preventive measures to supply sufficient fresh water to meet the needs of the population and industries. In areas prone to flooding and underflooding as a result of the operation of floodgates, it is also necessary to reconstruct hydraulic structures (raise foundation level, expand drainage systems, build reservoirs to collect flood water etc.).

Introduction. Swirling flows are widely used in hydraulic engineering particularly in the spillway systems of hydroelectric systems and kinetic energy absorbers. An experimental setup for the study of circulation flows by non-contact laser volumetric method is described. The principle of the method and the main characteristics of the recording equipment are given.
This installation allows to carry out physical modelling of complex flows to obtain kinematic and dynamic characteristics of the flow.

Materials and methods. The study of various physical phenomena requires compliance with certain modelling laws. When modelling hydrodynamic phenomena, it is necessary to observe geometric, kinematic and dynamic similarities. One of the most important concepts of any kind of modelling is similarity criteria. Based on these criteria, an experimental stand is designed. The air flow is generated by AeroLab wind tunnel. PIV system consisting of two Imager HS cameras and NL 200-15 laser is used as measuring equipment. To swirl the flow, a local mono-vortex axial type vane swirler is used. Synthetic oil is used as indicator particles for imaging.

Results. An experimental stand for modelling studies of vortex flows in the flow path of a hydraulic turbine, an optimal scheme for the arrangement of measuring equipment was developed and velocity distribution diagrams along and across the flow were obtained.

Conclusions. The developed scheme of instrumentation arrangement allows obtaining high-quality images of the flow suitable for further processing. The velocity distribution diagrams constructed as a result of the experiments correspond to those previously obtained by other researchers. The created experimental stand can be used to fulfill a wide range of tasks, for example, to study the possibility of using spiral chambers as spillways with counter-vortex energy dampers.

Introduction. Overflow air heating is a rarely used, but possessing a significant economic effect technology, the research of which is given insufficient attention. The subject of the research is the parameters of the thermal and humidity state of the air. The purpose of the research is to develop an algorithm describing the change of air state during the work of overflow air heating. Research objectives: to develop a model of air state change for overflow air heating; to apply the developed model and to formulate the recommendations on the organization of the overflow air heating for the warehouse building.

Materials and methods. The research methodology is based on the traditional laws and equations of heat and mass transfer, aerodynamics and continuum mechanics; application of I–d diagram and the rules of construction of heat and humidity air treatment; principles of operation and design of ventilation equipment; sanitary and hygienic bases of ventilation design. Selection of climatic data, properties of materials, as well as the development of design solutions were carried out in accordance with the current regulatory documentation.

Results. An algorithm including methods and models and describing the change in the state of the air for overflow air heating was developed. A model of air cooling in an unheated room was developed. It was tested on the example of a warehouse building with an unheated part. It confirmed the relevance of the developed model. Additionally, recommendations on
the organization of optimal air distribution and selection of equipment were designed.

Conclusions. The application of overflow air heating, calculated according to the proposed algorithm, will make it possible to increase the energy efficiency solutions in the field of ventilation of industrial buildings. The use of the algorithm implies that the organization of overflow air heating does not violate the technological process and requirements for fire and sanitary-hygienic safety of the building.

Introduction. Engineering systems are an integral part of all buildings. It is they who provide a comfortable stay and provide vital activity for a person. The role of energy-saving measures used in the construction and operation of engineering systems is very important. With the help of these technologies and their improvements, energy conservation of natural resources takes place. Energy efficiency in technology helps humanity to reduce the cost of energy resources, but at the same time to ensure the necessary level of technological processes in buildings. This article will show the problem of energy saving in mechanical ventilation systems. To implement energy-efficient use of resources, an improved recuperator unit with an increased efficiency is proposed. Currently, for engineers, there should be a greater choice of used recuperator designs with an increased efficiency, which can be used for different types of objects and technical conditions.

Materials and methods. The recuperator is offered as an analogue of existing samples and relates to the field of energy efficiency in ventilation systems.

Results. An increase in efficiency compared to analogues due to an increase in the area of contact of heat carriers, due to a special internal design capable of more uniform heat transfer, due to a non-standard layout of the recuperator unit to avoid freezing and “defrosting” of condensate at the heat transfer surface. Application in many types of buildings, as there is minimal mixing of supply and exhaust air. The operation of the ventilation system is regulated by automation, in order to obtain a more comfortable microclimate in the room.

Conclusions. The new design acquires an increased efficiency compared to analogues.

Introduction. Apartment heat supply refers to the provision of heat to the heating, ventilation and hot water supply systems of apartments. At the present time, wall convection gas boilers are used as heat generators for apartment heat supply. Comparison of energy, ecological, economic indicators of autonomous heat supply system when replacing gas heat generators with electric ones is given. The issues of equipment safety and costs of service maintenance are considered. Constructive and architectural solutions of equipment placement are proposed.

Materials and methods. Official data of Rosstat of the Russian Federation, reports of the Ministry of Energy, the Ministry of Economic Development, current GOSTs and regulatory documents for calculation of heat loss through enclosing structures are used. Calculations were carried out by methods of mathematical modelling.

Results. The total power consumption capacity of an apartment household, including electric heat supply, does not exceed 15 kWh. The issue of peak short-term exceeding of the allocated power and the operation of devices for automatic shutdown of household electrical power is solved by setting priority distribution of the allocated power. The carbon intensity of heat power production by electric boilers does not exceed the total average CO2 emission of hydrocarbon fuel heat generators. When using electricity tariffs for houses with electric stoves, the total cost of heat supply by electric boilers does not exceed the standards of payment for district heating of multi-storey buildings. Explosions and gas poisoning are excluded.

Conclusions. Autonomous electric heat supply of apartment households has a number of advantages in comparison with apartment heating based on gas heat generators and centralized heating with boilers on gas, coal and liquid fuel. Due to the fact that tariffs for electricity, district heating, gas supply in the regions of the Russian Federation change many times, climatic and environmental conditions are different, it is advisable to calculate the efficiency of the use of electric heat supply separately for each subject of the Russian Federation.

Introduction. The significance of road construction both in investment and construction activity and in the national economy in general is characterized. The specificity of investment and construction activity management, including road construction, which has a multi-level project approach in its basis, is noted.

Materials and methods. The research methods are a review of information sources, analysis of the project approach and the basics of road construction management, the usage of a systematic approach with the allocation of project management levels, generalization of professional experience in the service of the state customer, comparative analysis of the material with the identification of problems and trends in the development of project management in road construction.

Results. The macro level of project management is considered, because, according to the country’s development goals, the development of road construction is included in the system of national projects. The problems of the management of the national projects, including “Safe high-quality roads” and “Comprehensive plan for modernization and expansion of the trunk infrastructure” are identified. The problems of the state customer practice in the sphere of road construction are analyzed and the specifics of the micro-project level of road construction are defined. The express review of the directions of project management improvement in road construction is presented. The measures of project management improvement are proposed at the inter-branch level, which will be effectively reflected at the micro level of specific road construction projects.

Conclusions. Based on the results of the analytical review, the key positions of methodological support for effective project management in road construction were identified: optimization of the value chain of investment and construction projects; consolidation of cost, schedule and quality management parameters into the project model; assessment and management of the moment efficiency of the investment and construction project; use of the synergetic effect of system components of project cost management; implementation of adaptive management of investment and construction projects, precedent management, production modelling and controlling system.

Introduction. The paper considers the questions of the formation of a new approach to the study of property complexes of universities, which are traditionally dominated by real estate. Their relevance is determined by the state policy of the Russian Federation in the sphere of higher education, the important priorities of which are the improvement of the property complexes management on the digital basis, orientation to the creation of world-class campuses in the future.

Materials and methods. The characteristics of the source materials of the study, compiled on the basis of official statistical data generated by the state authorities of the Russian Federation, are presented. The insufficiency of official reporting data for a full-fledged study of the issues of real estate development within the property complexes of universities is noted, there is only the possibility to determine their main characteristics related to the structure and investments in the context of certain types of property. It is emphasized that during the transition to digitalization in all spheres of the economy, it is important to transform significantly the statistical information related to the property complexes of universities.

Results. Three aspects in the analysis of real estate objects were studied, in the context of which a comprehensive analysis of the effectiveness of state budget investments in the property complexes of Russian universities was carried out. The trends that are significant for assessing the current state and forecasting the situation with the construction and reconstruction of real estate as part of the property complexes of universities were identified. The main tendency, on which the attention of the authors was focused, was noted — the risks of incomplete construction, which should be reduced in order to ensure the effectiveness of the implementation of the Russian Federation state policy in the sphere of higher education.

Conclusions. In this regard, in terms of discussion, a set of measures that can be implemented at the state level in the context of digitalization was proposed, starting with the expansion of the information base on operated, under construction and reconstructed real estate, ending with proposals to include indicators of the state of university property complexes in
the indicators of their ratings, including on the basis of the creation of an information system on the state of real estate objects on a digital platform.