Vol 19, No 7 (2024)
Architecture and urban planning. Reconstruction and refurbishment
Reconstruction of built-up urban areas taking into account accessibility to limited mobility population groups: the case of Krasnodar
Abstract
Introduction. The development of a comfortable living environment for persons with disabilities is one of the most important tasks in the modern world. To a large extent, its implementation depends on housing conditions of wheelchair users, as well as principles of their settlement in multi-apartment residential buildings in cities. Physical barriers in the architectural environment are the most pressing problem hindering rehabilitation and socialization of disabled persons. Uncomfortable housing conditions can hinder therapeutic and preventive care aimed at health improvement, and physical barriers in housing and yard spaces can hamper the socialization of disabled residents. The problem is more relevant than ever, because due to the ongoing Special Military Operation, the number of physically challenged persons is growing fast. With this in mind, it is important to continue adapting residential buildings for limited mobility population groups and creating a more comfortable environment for all urban residents.Materials and methods. The article analyzes (1) the way wheelchair users take up residence in large-scale development areas in the post-war Krasnodar, (2) the settlement of wheelchair users in urban districts, (3) the residence of wheelchair users in buildings with a different number of storeys. Contradictions are identified between current urban development conditions and surrounding architecture, on the one hand, and the needs of limited mobility residents, including their socialization, on the other hand. Criteria for selecting design solutions are developed; recommendations are provided for the reconstruction of existing residential buildings, equipping and modernizing the urban environment, raising awareness of problems to be tackled by disabled persons.Results. A list of steps is proposed to solve problems of housing conditions and principles of resettlement of disabled persons. In particular, factors impeding the treatment, preventive care and socialization of wheelchair users are considered, and their elimination plan is proposed. The article provides a theoretical justification for techniques and principles of architectural design of buildings, taking into account the accessibility of standard residential buildings to limited mobility persons.Conclusions. The article describes methods and techniques for solving several most important problems of wheelchair users in Krasnodar, in particular, their accessible living environment. The appropriateness of the settlement of disabled persons in the existing urban development and reconstruction of this architectural environment were analyzed; methods for designing buildings that meet the housing requirements of limited mobility persons were presented. Also, a social approach to developing a comfortable living environment for such members of society was formulated and analyzed to ensure their integration into the life of society, equal access to infrastructure, work and education.
Vestnik MGSU. 2024;19(7):1069-1078
1069-1078
Construction system design and layout planning. Construction mechanics. Bases and foundations, underground structures
Space frame structures in domestic design practice and their installation methods
Abstract
Introduction. Modern construction demonstrates the wide use of various space frame types, because of their efficient from an engineering point of view, architecturally expressive, economical and durable. Large spans required increased frame rigidity; in such situations, space frames are more economical than classic flat trusses solutions. The most economical, both in material consumption terms and in the work cost are sparse structures. Such constructions meet all industrial and civil buildings requirements and have short building period. Not all safety requirements meeting building algorithm can be developed on currently existing technical base. More than that, domestic norms base does not include construction loads calculation methods. Critical differences in structures types determine building organization process but there are only general space frame building recommendations in domestic technical literature.Materials and methods. The space frame advantages and disadvantages are considered, the main area of application of this type of structures is determined. On the basis of material consumption and the most commonly used spans in modern buildings and structures research results, it was decided to study standard solutions developed by domestic research institutes. The main technical characteristics of structural blocks of the most common series are described. The main disadvantage of space-grid structures in general is the installation technology, so the methods of their installation are considered. The advantages and disadvantages of each method are analyzed, their field of application is determined.Results. The review and analysis of existing structural systems, including serial solutions of coverings and methods of their construction are performed. The most optimal method choosing criteria for structural blocks erection are determined. It was revealed that serial structural blocks such as “Kislovodsk” and “Moscow” do not have an exact installation algorithm. Therefore, an individual project is developed for the buildings with such coverings.Conclusions. The currently existing technical base is not enough to develop erecting structures algorithm that meets all safety requirements, and calculations for construction loads have not yet been made on its basis. To date, there are general provisions that have been developed for all coverings, but their use often becomes extremely dangerous due to critical differences in the types of structures.
Vestnik MGSU. 2024;19(7):1079-1090
1079-1090
Advanced technique for flexible cable analysis
Abstract
Introduction. Cable structures belong to perspective roof systems. Specialized software packages for structural analysis, however, do not provide optimization tools for obtaining efficient design solutions of the cable structures. Thus, development of improved methods for design and analysis of cable systems is an important task to be solved. An advanced technique for flexible cable analysis is proposed. It includes ordinary operations of summing the coefficients and their products. The technique is applicable for non-commercial mathematical software packages with numerical simulation tools included, thus providing structural optimization capabilities.Materials and methods. The technique proposed is based on the sine-series expansion of the external load and the shape function of the flexible cable. The differential equation of cable equilibrium is thus transformed into the set of algebraic equations. The cable length is expressed in algebraic form by means of the power expressions for the sum of the series.Results. The equation for the flexible cable is derived. It includes cable ordinate, axial stiffness, relative elongation and the external load parameters. The technique for determination of the axial stiffness of the cable is proposed under the operability conditions. The techniques for finding load-induced vertical displacements, as well as the initial cable sag and the undeformed length are given. The length of the cable under load and the ordinate given the cable length are proposed.Conclusions. The technique for flexible cable analysis allows taking into account distributed transverse external loads. For a combined load the coefficients of the series are the sum of the particular load coefficients. The technique is intended for automated structural solution. It allows facilitating the preliminary design stage, thus providing optimal parameters determination and in-depth design study implementation. Further development of the proposed technique encompasses the fields of non-shallow cable analysis, multy-chord cable systems, cable structures with stiffening girders, strutted cable systems and spatial roof structures.
Vestnik MGSU. 2024;19(7):1091-1103
1091-1103
The efficiency of the seismic isolating sliding belt under the impact of the most unfavourable earthquake accelerograms
Abstract
Introduction. Research was carried out on the performance of monolithic reinforced concrete buildings of varying heights with and without a seismic isolating sliding belt when subjected to the most unfavourable earthquake accelerograms. The objective of the study is to assess the effectiveness of seismic isolation in the form of a sliding belt at the foundation level under the action of the most unfavourable earthquake accelerograms using a direct nonlinear dynamic method.Materials and methods. The study employed a direct dynamic method based on an explicit integration scheme of the equation of motion (the central difference method). To determine the most unfavourable earthquake accelerograms, a method was used that accounted for all the most significant natural frequencies of the building under consideration.Results. Based on the calculations conducted, relative displacements and stress intensities for the building as a whole and in detail for the most loaded floor were determined. The analysis of the obtained results showed a significant reduction in shear displacements and stress intensities with the use of seismic isolation in the form of a sliding belt at the foundation level.Conclusions. When selecting the type of seismic isolation, its cost, as well as the labour intensity of manufacturing and installation, must be considered. It is necessary for the seismic isolation systems used to be available for mass construction, less complex, and maximally effective. Proven materials and technologies for the installation of these systems, which do not require specific skills and qualifications, should be used. Seismic isolation should provide comprehensive protection against the most likely seismic impacts. Conducted research shows that the seismic isolating sliding belt meets the above requirements. Unlike widely used rubber-metallic and pendulum sliding bearings, seismic isolation in the form of a sliding belt at the foundation level does not require factory manufacturing and can be implemented directly at the construction site.
Vestnik MGSU. 2024;19(7):1104-1115
1104-1115
Construction material engineering
Nanomodified cement composition
Abstract
Introduction. The focus area of construction materials science is to create materials with better performance characteristics. The most common construction material is concrete that has various purposes. The development of the construction industry leads to the design of increasingly complex structures, whose construction requires high-performance concretes featuring greater reliability.Materials and methods. Reported research data on using various nano-modifying additives for concrete are presented. Co-using carbon nanotubes (CNT) and plasticizer SP-3, as well as adding the nano-modifying additive by the method of ultrasonic dispersion are proposed as a composite additive for concrete.Results. The results of a series of tests are presented. The tests were aimed at studying the effect of a composite additive on the strength characteristics of fine-grained concrete. An increase in the compressive strength of concrete modified with CNTs was detected. Electron microscopy was employed to find that the use of nanomaterials changes the structure of concrete at micro- and nano-scale levels.Conclusions. Electron microscopy studies show the presence of fine-grained concrete areas modified with carbon nanotubes. However, this nano-modifying additive does not spread throughout the entire mixture. Therefore, additional actions should be considered to make the components spread throughout the mixture. The use of different type of mixers can have a positive effect on the dispersion of CNTs.
Vestnik MGSU. 2024;19(7):1116-1124
1116-1124
Adding zeolite to multi-component fine-grain concrete used for 3D construction printing
Abstract
Introduction. Requirements, applied to materials used for 3D construction printing, can be met by adding modifiers at the stage of designing fine-grained concrete compositions. Natural zeolites can be considered highly effective finely dispersed additives capable of adjusting properties of concrete mixtures, that are particularly relevant for remote development areas having deposits of this mineral raw material.Materials and methods. Research works and experimental data are reviewed to analyze the use of zeolites as a mineral additive in construction. Zeolites can partially, to different extents, replace cement in concrete to optimally meet the requirements of construction 3D printing. The setting time, the density and the dynamic shear stress of various compositions of concrete mixtures, as well as the density, ultimate compressive and bending strength values were determined for mature concrete. Results of strength and calorimetric testing were used to evaluate the activity of zeolite.Results. The best performance was demonstrated by the specimens with 5–15 % zeolite content by the cement weight. The information is provided about the time it takes for the density of concrete mixture to become critical to ensure its suitability for a 3D printer, which is reduced by 60 to 80 minutes for compositions with the 5–15 % zeolite content compared to the controlling composition, provided that and the mixture suitability period can be optimized by choosing the concentration of zeolite. The initial density of the concrete mixture, evaluated using the Vicat cone penetrometer, did not demonstrate any great changes when the share of zeolite was increased.Conclusions. Zeolite improves mechanical characteristics of fine-grained concrete and adjusts the setting time depending on the concentration of the mineral filler. Hence, zeolite can be considered as an effective component of concretes suitable for additive technologies.
Vestnik MGSU. 2024;19(7):1125-1137
1125-1137
Hydraulics. Geotechnique. Hydrotechnical construction
Stability analysis of cellular structures made of flat metal sheet piles
Abstract
Introduction. Cellular structures are internationally used as temporary and permanent structures. They are made of interconnected sheet piles forming adjacent cells, and they are usually filled with backfilling soil. When cellular structures are used as cofferdams, massive cells (1) make the use of cement and mortar unnecessary and (2) allow for the foundation soil to be excavated to a shallow depth. Since there are practically no bending moments in sheet piles of cellular structures due to their shape and sheet piles are mainly in tension, flat sheet piles are used to make these structures.Materials and methods. In this study, stability of a cellular structure was analyzed in compliance with effective regulatory documents. Several values of (1) the diameter of sheet piles and (2) the sheet pile driving depth were selected to study and compare methods of stability analysis. In addition to stability, the safety factor of interlocks was found for all design sections. Analytically obtained results were compared with those computed in two- and three-dimensional settings using Midas FEA NX software package.Results. Graphs were made to demonstrate the dependence between stability factors, the depth and the diameter of a cellular structure. The results computed in two- and three-dimensional settings using Midas FEA NX software package were compared with those obtained using analytical methods of stability analysis.Conclusions. Results of numerical modeling made in the two-dimensional setting are similar to the analytical solution. They show a substantially smaller stability factor compared to the three-dimensional problem.
Vestnik MGSU. 2024;19(7):1138-1150
1138-1150
Engineering systems in construction
Thermal and acoustic analogy for the study of thermal acoustic physical properties of solid materials
Abstract
Introduction. The article addresses the method of thermal and acoustic analogy, used to determine thermal and acoustic properties of solid building materials. A mathematical study is provided, which enables identifying parameters, dependencies and criteria characteristic of the propagation of temperature and sound waves in solid materials and to derive a new physical meaning of thermal conductivity. The mathematical experiment is confirmed by the experimental study conducted using a fluoroplastic specimen.Materials and methods. The method developed by the authors for determining a set of thermal and acoustic properties of solid materials is based on thermal and acoustic analogy. Temperature and sound vibrations (waves) propagate in a solid body according to the cosine law and are easily reproduced in laboratory conditions, which made it possible to conduct an experimental study by measuring the temperature and density of a heat flux on the surface of a specimen.Results. Experimental data on temperature and heat flow were obtained from the experiment conducted using the specimen under study, which made it possible, using the methodology developed by the authors, to identify thermal and acoustic properties of the material, including thermal conductivity, volumetric heat capacity, thermometric conductivity, surface veloci-ty of temperature waves, as well as the acoustic velocity of sound in the material. In addition, the mathematical experiment on thermal and acoustic analogy allowed the authors to establish the law of a temperature wave. Moreover, this law enabled formulating a new physical meaning of thermal conductivity of a substance.Conclusions. Experimentally identified thermal and acoustic properties of the material are consistent with the data provided in the reference and engineering literature, the discrepancy does not exceed 5 %, which confirms the validity of the mathematical experiment. Thermal and acoustic analogy makes it possible to determine not only the thermal conductivity, but also the speed of sound in materials by temperature and heat measurements taken on the surface.
Vestnik MGSU. 2024;19(7):1151-1160
1151-1160
The role of heat transfer resistance of a window in formation of resulting temperature at the boundary of habitable space in a room
Abstract
Introduction. According to current regulations, values of required heat transfer resistance of external enclosing structures must comply with the purpose of a building, a structure itself and the number of degree days in a heating period. This technique applies to all external enclosing structures, including windows. However, windows have greatly lower heat transfer resistance than solid envelopes. Therefore, windows have a greater effect on temperature than solid envelopes at the boundary of habitable space in a room.Materials and methods. The resulting temperature at the boundary of habitable space is lowest when outdoor temperature is lowest, or when temperature is lowest for five days in a raw. It has been found out that during such periods standards of resulting temperature are not met. A regression curve, made using the least squares method, is presented; it describes the relationship between t592 and the heating season degree-day (HSDD) for nursery and junior groups of preschool institutions in 30 cities of the Russian Federation. Some points are below the trendline. It is for such cities that it is proposed to take into account not only the HSDD, but also t592 when standards are set for resistance of windows to heat transfer.Results. Resulting temperatures at the boundary of habitable space in a room are determined. They show that optimal requirements for resulting temperature are never met, while acceptable requirements are met for all values of heat transfer resistance of windows and exterior walls, even if resistance to heat transfer is normalized. As for the local asymmetry of resulting temperature, its standards are also met at all times. Values of resistance of windows to heat transfer are calculated to find those that correspond to optimal resulting temperatures at the boundary of habitable areas of rooms for nursery and junior groups at preschool institutions if basic values of resistance of exterior walls to heat transfer remain unchanged. In a large number of cases, values of resistance of windows to heat transfer greatly exceed the maximum value set by Construction Regulations 50.13330.Conclusions. If the choice of a large value of window width is only explained by aesthetic reasons, the window’s resistance to heat transfer must exceed 0.8 m2∙°С/W, despite higher costs of such windows.
Vestnik MGSU. 2024;19(7):1161-1172
1161-1172
Technology and organization of construction. Economics and management in construction
Methodology for delimiting borders of the St. Petersburg agglomeration
Abstract
Introduction. The lack of unified approaches to (1) formation and development of agglomerations, (2) the regulatory legal framework for the methodological support of agglomeration processes, (3) the official conceptual framework in this area, (4) the assessment of agglomeration effects, (5) the approved methodology for delimiting agglomeration boundaries hinders the process of making informed decisions needed to solve a number of territorial, socio-economic, and transport problems arising in connection with the expansion of trans-regional integratory interactions between various constituent entities of the Russian Federation. In this regard, development of a border delimitation methodology for the St. Petersburg agglomeration is particularly relevant. The subject of the research is regulatory and methodological support for agglomeration processes. The goal is to develop a system of methodological support for creating and developing urban agglomerations within the framework of a well-balanced urban planning policy and legal framework of integratory processes in agglomerations.Materials and methods. The material for the study is the research focused on formation and development of agglomerations. Methods of system analysis and generalization of research results and practical work were applied to set the criteria for delimiting the boundaries of agglomerations. A methodology for delimiting the boundaries of the St. Petersburg agglomeration is proposed on the basis of analysis of research works of Russian scientists, results of practical research by St. Petersburg specialists, and special features of the St. Petersburg agglomeration.Results. The most complex theoretical and methodological problems of delimitation of the boundaries of the St. Petersburg agglomeration are identified; basic principles of formation and development of urban agglomerations are formulated to define the requirements for establishing boundaries; the main criteria for the delimitation of the St. Petersburg agglomeration are formulated, taking into account its specific features. A methodology for establishing the boundaries of the St. Petersburg agglomeration is proposed. Its main stages and research methods, used at each stage, are highlighted. The main problems of the legal support of formation and development of agglomerations are formulated.Conclusions. The research novelty and practical significance of the study result from the problems identified in the field of the regulatory support of agglomeration processes, which do not allow intensifying the development of agglomerations. The proposed methodology for establishing the boundaries of the St. Petersburg agglomeration is based on objective spatial development patterns of the two constituent entities of the Russian Federation and takes into account specific features of their interaction.
Vestnik MGSU. 2024;19(7):1173-1185
1173-1185
Analysis of principal characteristics of modern university campuses
Abstract
Introduction. In any society education and science are at the core of social and economic development. Special conditions should be in place to improve the quality of education, make it more attractive, develop science and boost its popularity, get talented young people involved in research activities. One of these conditions is a proper environment for life, education, work and intellectual development. Cases of the largest universities around the world were analyzed to choose the way to arrange the area and infrastructure of an educational institution. The idea is that areas of such universities feature complex spatial arrangement patterns known as “a campus”. According to Presidential Instructions No. Pr-419, by 2030 a network of modern campuses should be created in Russia. The purpose of the study is to identify basic campus arrangement principles, which should serve as the basis for an approach to designing world-class campus spaces and developing management mechanisms of their operation. The identification and formulation of these principles makes it possible to (1) formulate an approach to architectural and spatial solutions, (2) outline requirements for a legal entity to be involved in a campus development project, (3) make a target campus model and identify criteria to benchmark the effectiveness of a campus project.Materials and methods. The authors analyzed 52 campuses located worldwide. The subject of the study was the arrangement of campus space, the search for tools of interaction with the urban environment, and the identification of functional features of a campus. The main research method was information analysis.Results. As a result of analysis of 52 modern universities, 5 principles of campus space arrangement were formulated: the openness of campus space, the hierarchy of space components, the identity of spaces, the use of specialization in architectural solutions, and the use of library spaces as “living rooms”.Conclusions. A study of basic principles of spatial arrangement of modern campuses allows concluding that a new approach to campus spaces has emerged. Campus space arrangement determines a model of interaction between basic processes, the openness or closeness of a university in respect of a city and its requests, and implements the university’s management culture.
Vestnik MGSU. 2024;19(7):1186-1200
1186-1200
Cross-country assessments of the housing sector based on the development of comparative analysis methodology
Abstract
Introduction. The article addresses cross-country comparative studies of the housing sector. Comparative studies allow quantifying the heterogeneity of spatial development and ranking various territorial economic systems. The purpose of the work is a comparative assessment of the countries of the world according to the state and level of development of the housing sector, as well as an assessment of the situation and identification of problems in the housing sector of Russia in comparison with other countries of the world. The object of the study is the housing sector, and the subject of the study is housing relations.Materials and methods. The work is based on the methodology of comparative studies. The authors of the article have identified four conceptual approaches to the implementation of comparisons in the housing sector: based on the concept of sustainable development of settlements, the concept of reproduction of housing, the concept of analysis ex post – ex ante and the concept of the life cycle of residential real estate. The study systematizes housing characteristics used for comparisons in the housing sector within the framework of four identified conceptual approaches. Methods of comparative research in the housing sector are analyzed in the article. It is shown that the index method is a most universal and informative one for the purposes of comparative research.Results. In this study, the authors tested an approach to cross-country comparisons within the framework of the concept of sustainable development based on the index method. Comparative studies of the housing sector were performed by determining the integral housing index, aggregated indices of housing and living environment adequacy, and the aggregated housing affordability index. The analysis of integral characteristics of the housing sector showed a great difference between countries in terms of the level of development of the housing sector and allowed analyzing the quality of housing conditions in the countries of the world.Conclusions. The study allowed to expand the methodology of comparative studies of the housing sector. The proposed methodological approaches to the implementation of comparative studies are quite universal and can be applied to cross-country and interregional comparisons. Results of comparative studies can become the basis for (1) a state policy of spatial alignment in terms of the development of territorial housing systems and (2) the housing policy formulation.
Vestnik MGSU. 2024;19(7):1201-1216
1201-1216
The market of full-cycle construction companies: analysis of the current state and key trends
Abstract
Introduction. In the present-day environment, development of the market of full-cycle construction companies needs a thorough research on key trends governing its operation and improvement. Due to the gradual digitalization of the construction industry, traditional approaches to its analysis, based on geographical and product boundaries in terms of the number, the floor area and the volume of constructed buildings, will become ineffective because they disregard alternative criteria characterizing digital construction markets. Against this background, the projected development of the market of full-cycle construction companies is misleading. The evolution of methods for analyzing the market of full-cycle construction companies is characterized by a shift towards the use of digital ecosystems by developers willing to interact with market players. Hence, big data and data access modes will become increasingly important in the construction industry. The purpose of the study is to analyze the current state and trends in the Russian market of full-cycle construction companies.Materials and methods. Theoretical analysis of research works, statistical data analysis and comparative analysis, data generalization and systematization are among the main research methods.Results. Key trends governing the development of the market of full-cycle construction companies were identified by means of secondary data processing and computing the average annual growth rate. The main factors determining the current state of the market of full-cycle construction companies were systematized. Opinions of scientists, experts, as well as statistics were analyzed to systematize the reasons and factors, characterizing the current state of this market.Conclusions. Despite the positive dynamics, observed in the market of full-cycle construction companies, some administrative and legal factors restrain its development and act as barriers to its qualitative changes. In turn, regulatory authorities must meet the challenge of introducing digital technologies in the construction industry amid sanctions and import substitution of software for full-cycle construction companies preferring foreign alternatives.
Vestnik MGSU. 2024;19(7):1217-1227
1217-1227