New issues - Известия Казанского государственного архитектурно-строительного университета.

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GROUNDS AND FOUNDATIONS, UNDERGROUND FACILITIES
Ilizar T. Mirsayapov, Niyaz N. Aysin  Assessment of the deep excavation effect on additional settlement of surrounding buildingsСтр.6
Resume:

Abstract: Problem statement: In restrained urban conditions the design and construction of new facilities is increasingly carried out in close proximity to existing buildings, which requires the development of a model for calculating the deformations of building foundations in a single system with foundations, basement and surrounding soil. The purpose of this work was to assess the impact of the excavation of a pit with a depth of 13 m next to an existing building without a protective fence. To do this, it is necessary to assess the influence of the deep excavation on the existing building and develop a calculation model for determining the deformations of the building foundation considering joint deformation in the system of superstructure and substructure - foundations - subgrade. Results: Complex modeling of the stress-strain state and numerical studies have made it possible to establish that the construction of a deep excavation led to simultaneous vertical and horizontal movement of the soils of the building foundation base 30.1 mm and 19.8 mm, respectively. There were a lot of shifting lines of the soil mass under the foundations, indicating the achievement of the first limit state of the foundations bases. The construction of a deep excavation led to excessive and additional deformation of the foundations, the tilt of the foundations and the building as a whole, as well as to the stress in the structures above the maximum permissible. Conclusions: The significance of the developed foundation model for the construction industry lies in the fact that it allows you to determine foundations settlement, taking into account the loading modes.

Keywords:
foundation settlement, deep pit, surrounding buildings, loading mode, design model.
BUILDING STRUCTURES, HOUSES
Mirsayapov Ilizar T.  Calculation of the strength of reinforced concrete sleepers taking into account the joint deformation with the ground baseСтр.14
Resume:

Problem statement. Reinforced concrete sleepers are special structures due to complex geometry and increased requirements for their crack resistance and endurance. The necessary crack resistance and endurance is provided by the use of prestressed reinforcement. The purpose of the study is to develop methods for calculating the endurance and crack resistance of reinforced concrete sleepers with prestressed core reinforcement on the basis of theoretical studies. Results. New methods for calculating the endurance and crack resistance of reinforced concrete sleepers with prestressed reinforcement have been developed. Conclusions. The significance of the results obtained for the construction industry lies in the fact that they make it possible to more accurately assess the endurance and crack resistance of reinforced concrete sleepers with prestressed reinforcement.

Keywords:
stressed reinforcement, crack resistance, endurance, reinforced concrete sleepers, creep of concrete
Khaidarov L. I., Kayumov R. A., Shmelev G. N., Gimazetdinov A. R.   Buckling of a concentrically loaded imperfect elastic column with identical nonlinear rotational connectionsСтр.23
Resume:

Problem statement. The connections of the demountable metal frame systems are often made of a wedge or cup type. In such connections the dependence of the bending moment on the angle of mutual rotation of the elements is nonlinear. Currently there is no engineering methodology for assessing the bearing capacity of a pillar with non-linear rotational end connections. The purpose of this article is to develop an engineering methodology for determining the ultimate compression force for an elastic prismatic column with nonlinear rotational connections with monotonically decreasing stiffness. The objectives of the study are derivation of dependencies for the normal force in a centrally compressed beam-column with and without initial curvature, analysis of the established dependencies and obtaining a methodology for determining the ultimate compression force. Results. An approximate formula is obtained for determining the compression force in an elastic column depending on its bending stiffness, the length and initial curvature, the function of the bending moment and the angle of rotation at the ends. Conclusions. The significance of the obtained results for the construction industry lies in the fact that the proposed formula allows determining the ultimate compression force for an imperfect elastic prismatic column with identical nonlinear rotational connections with monotonically decreasing stiffness.

Keywords:
beam-column with non-linear connections, post-buckling behavior, initial curvature, monotonically decreasing stiffness, second-order analysis
Information about the authors.  Analytical calculation of deflections of a planar externally statically indeterminate trussСтр.36
Resume:

Problem statement. A planar statically determinate lattice truss with a straight lower chord and a curvilinear upper chord has three movable and one fixed supports. The task is to derive a formula for the dependence of the amount of deflection of the truss and the horizontal displacement of the movable supports on the number of panels. To determine the forces in the rods and the reactions of the supports, a system of equilibrium equations for hinge joints is compiled and solved. The deflection is determined using the Mohrs integral. The generalization of analytical solutions for a number of trusses with a different number of panels to the case of an arbitrary number of panels is performed using Maple symbolic mathematics operators. The coefficients for similar expressions in the desired formula are determined from recursive equations compiled in this system based on the analysis of the sequence of solutions. Results. It is shown that for a certain number of panels the truss has the property of instantaneous change. This is confirmed by the found distribution of the virtual velocities of the construction hinges. The actions of a uniform distributed nodal load along the curvilinear upper or lower chords and the action of a concentrated load on the middle of the span are considered. Analytical dependences of forces in the most stretched and compressed elements on the number of panels in the truss are obtained. Conclusions. The proposed scheme of the truss, which allows obtaining the final formula for the dependence of the deflection and forces in the rods for an arbitrary number of panels. It is shown that the deflection depends abruptly on the number of panels, which makes it possible to increase the rigidity by choosing the optimal number of panels.

Keywords:
truss, deflection, Maple, induction, kinematic variability
Artem S. Petrov, Aleksey I. Ivantsov, Ainur M. Yuzmukhametov  Assessing overmoistening of structures in places of heat engineering inhomogeneitiesСтр.45
Resume:

In existing regulatory documents (SP 50.13330 and ISO 13788), overmoistening protection is taken into account along the surface of the structure, that is, in thermally homogeneous parts of the enclosure. There is no requirement for protection against overmoistening of inhomogeneous nodes. At the same time, field and numerical studies show that in many cases overmoistening occurs precisely in places of thermal inhomogeneity. A qualitative assessment of the degree of moistening of thermal inhomogeneity becomes available to a wide range of engineers in connection with the advent of specialized software. However, the questions of both the method of such a calculation and the interpretation of the results obtained remain unclear. The results of a numerical study of the moisture state of the enclosure fragment based on a software package with a two-dimensional transfer of vaporous moisture according to G. Glaser are presented. Based on the moisture fields obtained, the calculated values of thermal conductivity over the fragment cross section were refined. An example of assessing overmoistening of a structure based on simplified stationary methods by G. Glaser, Safin I.Sh. and Kupriyanov V.N.is given. It is shown that the fulfillment of the requirements for protection against overmoistening of a homogeneous fragment of a structure in accordance with paragraph 8 of SP 50.13330 is not enough, in addition to existing calculations, it is necessary to assess possible moistening in places of heat engineering heterogeneity. The alternative method for protecting structures from moistening in places of heat engineering heterogeneity is proposed based on the methods of G. Glaser, I. Sh. Safin and V.N. Kupriyanov.

Keywords:
external wall structures, temperature and humidity conditions, condensation, humidity fields, heat engineering inhomogeneity
Ilshat Talgatovich Mirsayapov,Ilnur Mansurovich Gimatdinov  Study of the stress-strain state of steel-reinforced concrete beams with partial embedding of I-sections in concreteСтр.56
Resume:

Statement of the problem. There are many ways to calculate reinforced concrete and steel structures, but at present there are no complete regulatory documents for the design of steel-reinforced concrete structures, for the case when a steel I-beam is embedded in a concrete body. In this regard, the issue of studying the work of steel-reinforced concrete structures is very relevant at the present time. Due to the lack of a complete regulatory framework for the calculation of steel-reinforced concrete beams with partial concreting of I-sections in concrete, there is a need for a model for calculating structures by numerical methods. The aim of the work is to develop a methodology and model for determining the destruction of concrete through the deformation diagram, using the ANSYS software package. Objectives of the work: to analyze the research and experiments of steel-reinforced concrete beams with partial sealing of I-sections in concrete and, based on the experiment, to propose a method for determining the destruction of concrete through a deformation diagram in the ANSYS software package. Results. A model is presented in the ANSYS software that describes the operation of a steel-reinforced concrete beam with a partial embedment of an I-section in concrete, which makes it possible to evaluate the stress-strain state of the entire section. Conclusions. The significance of the obtained results for the construction industry lies in the fact that the proposed model in the ANSYS software allows us to evaluate the stress-strain state of the structure. This is a significant contribution to the development of the methodology and improvement of the regulatory framework for calculations in the design of steel-reinforced concrete structures.

Keywords:
steel-reinforced concrete, steel-reinforced concrete beam, ANSYS, numerical methods.
BUILDING MATERIALS AND PRODUCTS
Ravil Z. Rakhimov  Fuel and energy complex, ecology and mineral bindersСтр.67
Resume:

The article presents an overview of the current state of the current problem of reducing the material consumption of the building materials industry by involving large-tonnage industrial wastes in their production, which includes various wastes of the fuel and energy complex. The types of waste generated and the volumes of waste accumulated by various branches of the fuel and energy complex have been analyzed. A review of modern achievements in the field of efficient waste management in the production of mineral binders, materials and products based on them is presented. The insufficient level of implementation of promising options for using waste in the building materials industry and reducing the burden of the fuel and energy complex on the environment is shown. The main directions for solving the problems of environmental safety, resource and energy saving in the production of cements and concretes are formulated

Keywords:
wastes, cement, fly ash, slag
Ayaz G. Khantimirov, Lyaylya A. Abdrakhmanova, Rashit K. Nizamov, Vadim G. Khozin  Wood-polymer composites based on polyvinyl chloride reinforced with basalt fiberСтр.75
Resume:

Problem statement. The paper presents the results of studies of wood-polymer composites (WPC) based on polyvinyl chloride (PVC) reinforced with short-fiber basalt fiber. The positive role of various fibrous fillers for WPC based on polypropylene and polyethylene is well known, but their effect on polyvinyl chloride WPC is poorly understood. The purpose of the work is to study PVC-WPC modified with short-fiber basalt fiber. The objectives of the study are: the creation of reinforced WPC with a uniform distribution of filler fibers, as well as the assessment of the influence of basalt fiber on the physical and mechanical properties of composites. Results. Electron microscopy data showed a uniform distribution of basalt fiber over the volume of the composite. The modification of the WPC led to an increase in bending strength by 22% and a decrease in water absorption by 32%. Conclusions. The significance of the results obtained for the construction industry consists in expanding the scope of WPC application by increasing the physical and mechanical properties of products.

Keywords:
polyvinyl chloride, wood-polymer composite, basalt fiber, fiber modifier, scanning electron microscopy, energy dispersion analysis.
Karina R. Khuziakhmetova, Lyailya A. Abdrakhmanova, Rashit K. Nizamov, Ludmila I. Potapova,   Structure of polymer blends based on polyvinyl chloride Стр.82
Resume:

The paper presents the results of the study of the structure of polymer blends based on polyvinyl chloride (PVC). Mixtures of polymers have properties superior to the properties of each component separately, which is associated with the interfacial interactions of the two polymers. The main research in the field of polymer blends is aimed at studying the structure of composites subjected to shock and tensile loads. The structure and fracture mechanism are determined by the ratio of components in the polymer mixture. Therefore, the aim of the study is to investigate the structure of polymer blends based on PVC and acrylonitrile butadiene styrene (ABS) triple copolymer. The objectives of the study are: studying the chemical composition of powdered ABS and extruded PVC/ABS polymer mixtures by infrared spectroscopy; comparing the structural features of PVC compositions at different concentrations of ABS. The main results of the study are that the structure of ABS by infrared spectroscopy, which determines the conditions of compatibility with PVC, has been evaluated. The effect of different concentrations of ABS on the structure of PVC compositions was considered. When adding ABS up to 20 phr the formation of a microheterogeneous structure of the composite is observed, and when adding 50 and 100 phr of ABS per 100 phr of PVC the formation of a continuous phase of two polymers was detected, which was confirmed by the results of enegodispersion analysis. The significance of the obtained results for the construction industry is that the formation of continuous phase of polymer mixture provides high impact strength of the final product compared to compositions based on individual polymers (PVC or ABS).

Keywords:
polyvinyl chloride, acrylonitrile-butadiene styrene, polymer mixtures, profile-finished products, structure, FTIR-spectroscopy, scanning electron microscopy, energy dispersive analysis
Denis S. Smirnov,Eduard M. Yagund,Valeriya E. Brodneva, Almaz Sh. Khasanov  Road surface material based on bitumen-rubber binderСтр.90
Resume:

Problem statement. The purpose of the project is to consider the possibility of using rubber waste as a modifying additive of petroleum bitumen, to study the effect of waste from the production of rubber and technical products on the physical and mechanical properties of bitumen binders. Results. Positive results of physical and mechanical properties were established when adding waste rubber products to bituminous binders, the use of a bitumen-rubber composition in the composition of crushed stone-mastic asphalt concrete (SMA) also provides regulatory characteristics Conclusions. It is assumed that the optimization of the technology of adding bitumen-rubber composition to the composition of the SHMA and its development will increase its physical and mechanical characteristics, which makes it possible in the future to increase the period of operation of asphalt-concrete road surfaces made on its basis

Keywords:
asphalt concrete, bitumen, strength, rubber-technical product, stabilizing additive, softening temperature, brittleness
E.A. Vdovin, P.E. Bulanov, I.V. Zhuravlev  The effect of cellulose stabilizing additives on the physical and mechanical characteristics of bitumenСтр.103
Resume:

The aim of the work is to study granular stabilizing additives with different cellulose content on the physical and mechanical characteristics of bitumen. The relevance of the study is related to the trend of increasing traffic intensity of motor transport in the Russian Federation. As a result, there is an increase in requirements for the inter-repair terms of highways, for environmental safety. Compliance with these requirements is facilitated by the use of crushed stone-mastic asphalt concrete with stabilizing additives that are more resistant to increasing loads. Results. Modification of bitumen with a stabilizing additive (containing cellulose and wax fibers – 60% and 40%, respectively) in an amount of 2% and 4% increases the following physical and mechanical characteristics: softening temperature along the ring and ball by 7.36% and 26.18%; needle penetration depth at 25 оС – 6.25% and 12.5%; extensibility at 0 °C – 105.24% and 74.33%, respectively. Modification of bitumen with a stabilizing additive (containing cellulose and wax fibers – 20% and 80%, respectively) in an amount of 2% and 4% increases the softening temperature along the ring and ball by 22.29% and 59.10 %; reduces the penetration depth of the needle at 25 °C – 10.34% and 5.49%; increases the extensibility at 0 °C – 110.35% and 9.27%, respectively. Conclusions. The regularities of the influence of stabilizing additives with different content of cellulose and wax fibers on the physical and technical characteristics of bitumen are revealed.

Keywords:
bitumen, crushed-mastic asphalt concrete, stabilizing additive, cellulose, physical and mechanical characteristics
CONSTRUCTION MECHANICS
Anvar V. Gumerov  Determination of the coefficients of forces acting on a rectangular prism in a two-dimensional flow by the method of discrete vorticesСтр.110
Resume:

In this paper, the calculation method of discrete vortices determines the aerodynamic coefficients of the section of a rectangular high-rise building in plan. The problem of two-dimensional unsteady separation flow around a rectangular cylinder by an incompressible medium is considered. Calculations were carried out for various rectangular sections at different integration steps and the number of attached vortices on the contour of a streamlined rectangle. It is shown that by varying these parameters, it is possible to obtain aerodynamic characteristics close to experimental data. Results. Time dependences of coefficients of aerodynamic forces for various rectangles are obtained. The distribution of the pressure coefficient over the surface of the rectangle at the maximum lifting force is given. We compared the obtained calculated dependences of the force coefficients and the Strouhal number for various rectangles with the available experimental data. Recommendations are given on the selection of the integration step and on the number of placement of attached vortices on the contour of the rectangle. Conclusions. The significance of the results obtained for the construction industry consists in the possibility of evaluating the structural elements of rectangular cross-section for strength and fatigue, using the calculated force coefficients. The calculation model makes it possible to determine the distribution of the pressure coefficient for finding wind loads on the fa?ade panels of multi-storey residential buildings.

Keywords:
method of discrete vortices, bound and free vortices, control points, rectangular prism, the Strouhal number, flow complex potential
URBAN PLANNING, RURAL PLANNING
Alexander A. Dembich,Olesya A. Baltusova  The historical center of Kazan - between transformation and preservationСтр.119
Resume:

The article analyzes the main existing documents related to the development of historical settlements, describes the current situation of the development of a historical settlement on the example of Kazan, where one of the key tasks is a significant antagonism between the representative function necessary for the capital of the republic and regulations aimed at preserving the planning and architectural qualities of the urban environment. The article describes the mechanisms that should become the basis for the correction of urban planning documentation on the territory of a historical settlement, be public and formalized. The purpose of the study is to determine, identify and preserve the historical and cultural identity of the city during the urban reconstruction of the urban architectural and spatial environment on the example of the territory of the historical settlement of Kazan, by highlighting the positive qualities of architecture and principles of urban planning characteristic of this settlement, for their preservation and with a qualitative change in the environment during new construction. The relevance of the study is due to the assignment in 2017 of the central part of Kazan with an area of 22.5 sq. m. the status of a "historical settlement". Results. The main results of the study consist in the formation of a methodology for the preservation and adequate development of the historical and cultural identity of a large historical settlement on the example of the city of Kazan. Conclusions. The developed methodology is of great practical importance and can be taken into account in real urban planning practice aimed at regeneration, renovation and reconstruction of existing historical territories.

Keywords:
historical and cultural identity, regeneration, planning structure, spatial regulation, historical settlement.
Yuliya A. Zakirova, Adel R. Sagdiev   Features of urban development of urban-type settlements in the structure of the Kazan agglomerationСтр.130
Resume:

Problem statement. The purpose of the study is to analyze the spatial and socio-economic development of urban-type settlements in the structure of the Kazan agglomeration, highlighting the priority directions of their spatial development. The object of the study is urban-type settlements (Zelenodolsk, Vasilevo, Nizhni Vyazovye, Innopolis, Laishevo) that perform the role of satellite settlements in the territorial structure of the Kazan agglomeration or have the potential to perform this role in the future. Results.The main results of the study are that the features of the development of urban-type settlements in the structure of the Kazan agglomeration are determined, priority directions of their spatial development are identified on the basis of a comprehensive analysis. Conclusions. The significance of the results obtained for territorial planning lies in the fact that a detailed study of the features of urban development of urban-type settlements within the Kazan agglomeration will determine the principles of territorial development of the Kazan agglomeration and form a model of its spatial development. These developments can become the basis of the concept of the territorial planning scheme of the Kazan agglomeration.

Keywords:
satellite city, planning structure, agglomeration zone, Kazan agglomeration
ARCHITECTURE THEORY AND HISTORY. HISTORICAL AND ARCHITECTURAL HERITAGE RESTORATION AND RECONSTRUCTION
Alfiya R. Minibaeva, Marat Sh. Fazleev  Architecture of spectacular buildings in the historical gardens of Kazan for the period of the second half of the XIX – early XX centuriesСтр.147
Resume:

Problem statement. Currently, the creation and revival of public urban spaces is an urgent topic in Kazan, in other wordsvarious national, federal, state programs and projects are in operation, investors are attracted. For this reason, there is a need to turn to historical experience in order to revive the structures located on the territories of public urban spaces. The purpose of the study is to identify the architecture of entertainment structures in the gardens of Kazan for the period of the second half of the XIX – early XX centuries. The objectives of the study include: -study of bibliographic, iconographic and archival materials related to the research topic; -identification of typology and architectural analysis of spectacular structures located on the territories of Kazan gardens for the period of the second half of the XIX – early XX centuries. Results. As a result of the study of the architecture of entertainment structures located on the territories of Kazan city gardens for the period of the second half of the XIX – early XX centuries, the following were identified: -the main types of structures are theaters, outdoor stages, bandstands, voxals. -architectural solutions, in other words structures of spectacular purpose were 1-2-storey symmetrical structures made of wood. The prevailing trend of architectural style is eclecticism. They were the dominant objects in the planning structure of the garden. Also in this study, the prerequisites for the appearance of entertainment facilities in the city gardens of Kazan are considered. Conclusions. The results of the research can be used in the restoration, design and reconstruction of public facilities on the territory of the historical center of Kazan and other historical settlements, as well as in a course of lectures on the history of architecture in construction and architectural educational institutions of Kazan and Volga region cities.

Keywords:
spectacular buildings, architecture of buildings and structures in the historical gardens of Kazan, estrade, open stage, theater
 
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