## ARCHITECTURE AND CIVIL ENGINEERING

### BUILDING STRUCTURES, BUILDINGS AND CONSTRUCTIONS

The article presents a comparative analysis of the results of the calculation of rigid pavement on the shear stability obtained by the classical engineering method and using numerical calculations. The conclusion is made about the possibility of using modern design tools to select the optimal design of rigid pavement.

Determination of the Area of Reinforcement of Reinforced Concrete Columns of Circular Cross Section

A mathematical expression has been developed for determining the cross-sectional area of reinforcement of an eccentrically compressed reinforced concrete column of circular cross section, which makes it possible to simplify consideration of the infl uence of structural indicators and quality parameters of reinforcement and concrete on the required area of longitudinal reinforcement of reinforced concrete column. An example of using this formula in the calculation is shown. This mathematical expression can be used in the design of reinforced concrete columns, racks of power lines and circular supports as the least time-consuming method of engineering calculation, allowing to determine the cross-sectional area of longitudinal reinforcement.

Method of Evaluation of the Fire Resistance of Composite Building Structures

The article describes a new method for determining the design fi re resistance of composite (steel-concrete) building constructions of buildings. The advanced algorithm of the decision of the fi re-technical task in the part of express calculation of design fi re resistance of composite building constructions is given. A new constructive form of composite reinforced concrete structure of the building has been developed and the system of actions for assessing the fi re resistance of its elements at the level of inventions, which are implemented in building practice, has been improved. The components of the creative result of scientifi c work and the content of the technical eff ect, including resource saving, are introduced, with the introduction of an innovative solution in the practice of fi re protection and providing fi re resistance of perspective building constructions of buildings.

A new type of formwork systems based on the use of BIM technologies and formwork sheets from polymeric materials for the erection of standard and individual building structures with a fi ne fi nish have been proposed. The statistical data on the development trend of monolithic housing construction in Russia and the world are given. The advantages and disadvantages of this technology are presented, it is shown how to deal with them. A system of paraffi n formwork has been proposed to facilitate restoration work, as well as works on the construction of architecturally expressive parts of the facades (moldings, sandriks, bulk compositions). An algorithm for working with it using spatial scanning of facades and 3D printing has been developed.

## ARCHITECTURE AND CIVIL ENGINEERING

### HEAT SUPPLY, VENTILATION, AIR CONDITIONING, GAS SUPPLY AND LIGHTING

The heat-shielding properties of three-layer external walls insulated with monolithic foam concrete are considered in the article. The temperature is given in rooms operated in intermittent heating conditions. An optimal exterior wall design is proposed using monolithic foam concrete for the construction of country cottages. For this design, the results of heat engineering calculations are presented using the analytical dependence of determining the heat transfer resistance, which ensures the minimum warm-up time of the wall. The results of the calculation are presented in tabular form for a given heating time and density of foam concrete. Also a relationship is described to determine the maximum allowable resistance to heat transfer of the outer wall at diff erent densities of monolithic foam concrete.

A mathematical model of gas fi ltration through a porous medium is described, which describes the movement of air during high-pressure forced aeration, which is needed to maintain a high metabolic rate of oil-destroying microorganisms. Aeration is necessary to create an aerobic environment when applying a promising method of sanitation of the geological environment by injecting a special composition containing oil-destroying microbial additives into the lenses of oil products. The equation of fi ltration in polar coordinates is obtained, taking into account the experimental data, which describes the dynamics of gas movement in a porous medium under conditions of forced high-pressure aeration. The functional dependences are revealed, when obtaining the values of which one can solve the obtained fi ltration equation.

The solution problems of the additional the sought-for function and additional boundary conditions based when using local coordinate systems, an approximate analytical solution of the heat conduction problem for a double-layer plate is obtained for symmetric boundary conditions of the first kind. The use of the additional sought-for function in the integral method of heat balance makes it possible to reduce the solution of the partial diff erential equation to the integration of an ordinary

diff erential equation.

Technique of Monitoring of Networks of Heating Boiler Room According to the Commercial Account

The technique of monitoring of production and consumption of thermal energy according to commercial and technological account on border of thermal networks of a heating boiler room is developed. The off ered approach on the basis of systems analysis allows to compare thermal loading, an expense, temperature and pressure of the heat carrier with their contractual values and to estimate quality indicators of heat supply. As an example results of monitoring of operation of the closed system of heat supply from an independent boiler room for a heating season of 2014-2015 are considered.

Improving the Efficiency of the Vortex Dust Collectors

It is proposed to use a modernized “wet” vortex dust collector for cleaning ventilation emissions from non-adhering dust. The design of the vortex dust collector contributes to its effi ciency by installing irrigation nozzles in the primary and secondary air connections made in the form of a Venturi tube, which allows reducing energy consumption during the cleaning of dusty air. Due to the multidirectional movement of dust particles and splashed water, active coagulation of dust particles and water particles occurs, as well as a liquid fi lm is formed on the inner surface of the separation chamber, which prevents the dust particles from rebounding from the separation chamber and facilitates their collection and washing into a collecting bin.

## ARCHITECTURE AND CIVIL ENGINEERING

### WATER SUPPLY, SEWAGE, CONSTRUCTION SYSTEMS FOR PROTECTION OF WATER RESOURCES

Development of the Rational Urban Engineering Systems for the Surface Wastewater Treatment

The results of studies and seasonal observations of the surface wastewater quality that generated in the territory of a modern large city are presented. The dependence of the surface runoff quality on the year season and the kind of urban development is shown. The eff ect of anti-ice reagents on the meltwater quality is noted. The article suggests a new approach to the making of a technological scheme for surface wastewater treatment. Based on the obtained data, a technological block-scheme of a local Wastewater Treatment Plant (WWTP) intending for surface wastewater treatment and operating in an automatic mode is proposed. The proposed technological solution takes into account seasonal changes in the surface wastewater quality in urbanized areas.

On the Problem of Viscous Incompressible Fluid Flow in a Flat Conical Slotted Channel

A precision pair operating under misalignment conditions, i.e. at a distortion of mobile elements of contactless consolidations is analyzed. The fl ow of a viscous incompressible fluid in a fl at conical slit gap is investigated. Since the boundary-value problem does not have an exact solution, an approximate analytical solution was found in the work that does not depend on boundary conditions. The equations of motion of a fluid are solved in the Navier-Stokes form by the method of small perturbations. The hydrodynamic parameters of a viscous fluid as it moves through a conical slit gap are determined. The profile of the velocity of the fluid in the form of the sum of a pressure flow with a constant pressure drop and flow due to the oscillation of the channel wall is constructed. Graphic illustrations are given with high and low frequency limits of oscillations.

The main methods of intensification of biological wastewater treatment by chemical, physical and biological factors are considered. The expediency of using biotechnological methods during commissioning works on biological treatment facilities in the modes of nitrification and denitrification, based on the use of biologic-enzyme preparations, magnetic treatment and lighting, is substantiated The results of research for urban wastewater on the model installation of bioreactors in the mode of nitrification and denitrification are given.

Priority Measures for the Renovation of Historic Urban Areas

The paper presents information on the sewage of residential areas in the historical buildings of Samara. Studies have shown that one of the main problems in the areas of historic urban development is the failure to comply with sanitary standards, due to the presence of yard dumps for collecting waste from non-canalized households. Based on the analysis of archival sources, about 40% of houses with courtyards that could theoretically be connected to a centralized sewerage network already by 1930.

## ARCHITECTURE AND CIVIL ENGINEERING

### BUILDING MATERIALS AND PRODUCTS

The article presents a method for calculating the composition of a two-component raw material mixture for producing lime-clay cement based on fuel-containing technogenic waste – gravitational waste of coal enrichment. A method for determining the optimal ratio of components in the charge, taking into account the calorifi c properties of the waste, is given. The key parameter, in this case, is the energy effi ciency ratio. The purpose of the calculation is to determine the ratio of components in the charge, which ensures maximum economy of process fuel. The results indicate the possibility of complete elimination of process fuel from the production cycle at the steady-state thermal process through the use of coal preparation waste.

## ARCHITECTURE AND CIVIL ENGINEERING

### THEORY AND HISTORY OF ARCHITECTURE, RESTORATION AND RECONSTRUCTION OF ARCHITECTURAL HERITAGE

Tectonics of Crystal Domes and Covers and Factors Defining their Volume and Space Composition

The article provides a brief history of the geodesic crystal dome structures. A set of factors that are determining conditions in the formation of the tectonics of the volume-spatial composition of dome structures is considered. The issues of plastic processing and plastic expressiveness of dome structures with diff erent structural scheme of the geometric breakdown of the surface are considered. A comprehensive assessment of the initial design conditions and the consideration of formative factors allowing the creation of expressive volume-spatial compositions of structures of various functional purposes using crystal dome shells are given.

The article views the classification and features of the formation of objects of landscape architecture in the structure of households of the estate building of the XIX – beginning of the XX centuries on the example of the city of Samara taking into account the town-planning features: social affiliation, location relative to the historic city center, density, height, functional and planning type of buildings. Emphasis is placed on the preservation of objects of landscape architecture within the borders of the existing households, which form the basis of the planning of the neighborhoods of the historic city center. Considering the identified classification a technique for the preservation and development of landscape architecture objects in modern conditions is proposed.

Architectural planning principles of urban bridges reconstruction

The bridges and overpasses of the city of Samara are considered, their main characteristics are identifi ed. A brief historical background of the appearance of the first bridges as simple engineering structures is given, the main temporary periods are highlighted. Examples of implemented solutions that characterize the main stages of the history of bridge construction are given: the Hohenzollern Bridge in Cologne, the Millennium Bridge in Gateshead, the Ponte Vecchio Bridge in Florence, the Golden Gate Bridge in San Francisco, the Russian Bridge in Vladivostok, the String Bridge in Jerusalem. The analysis helps to understand how a modern bridge, located in the city building system, aff ects it, complements and enriches it, combines many functions and advanced technologies, and also has architectural expressiveness.

The impact of architectural and historical environment on religious objects of Samara

The purpose of the article is to identify the impact of the system of identifiers of the architectural and historical environment on the religious architecture of Samara on the considered and identifi ed historical stages of the development of the city. It is shown that due to the particularly rapidly developing cities of our time, including historical ones, the historical heritage is the first to be in danger of complete or partial extinction. From here it becomes apparent the preservation of the heritage of cities and the preservation of the identity of the historical city. As a result, a typical image of the Samara religious architecture was determined throughout its development, characteristic types, styles, influences of external and internal ethnos were established, and productive forces were identified, which are the basis for the development of the city of Samara at each historical period.

In the course of this work, the following tasks were identified: 1) the formulation of the definition of “environmental tourism”; 2) identification of opportunities and prospects for the development of environmental tourism with the help of additional efforts (saturation of infrastructure, scenery, changing architectural and landscape organization, entertainment programs, etc.); 3) identification of areas of valuable development; 4) identification of areas that most clearly form the image of the city; 5) identification of tourist routes; 6) development of principles and techniques of cultural and entertainment organization of zones. In this work, we set as our goal the fixation of sections of urban fabric that have survived to our time with a stable morphotype of building up. We give a brief justifying description of this morphotype and show the general approach to environmental tourism as a complex event. Issues of detailed routing, economic calculations and legal justification are beyond the scope of this work. The proposed approach can potentially both increase the tourist attractiveness of the city for nonresident and foreign tourists, and will contribute to the preservation of the historical heritage in its most vulnerable component – a valuable background building. Such activity can stimulate the development of business and investment attractiveness of the historic city.

## ARCHITECTURE AND CIVIL ENGINEERING

### ARCHITECTURE OF BUILDINGS AND CONSTRUCTIONS. CREATIVE CONCEPTS OF ARCHITECTURAL ACTIVITY

The basics of functional-spatial typology in the context of the design of residential interiors are viewed. The structure of functional-spatial relations that influence the formation of the design concept of a residential interior is described in detail. The classification and definition of types of internal space are given. The basic requirements for the selection, taking into account the qualitative and quantitative types of functions of the residential interior are developed. Definitions of nominal and vital types of functions are given as well as mass, group and individual types of functions in relation to residential interior. The classification of the main spatial schemes and their modifications is given. The methods for analyzing the reference spaces for determining the compositional strategy and choosing the space-planning concept are shown. The definition of project goals and objectives and algorithms for their solution are given.

Atrium Spaces: Realization of Fractal Models of Local and Urban Structures

The paper refers to the functional purpose of the atrium in architecture and town planning. The authors interpret atrium spaces in the context of a fractal-cluster model of environment formation. The study includes theoretical and conceptual development of the formation of space as a multilayer structure, based on key elements (clusters). The authors investigate the elements of space that are formed by means of atria taking into account fractal concepts. The hypothesis of sustainable development of urban spaces is stated by introducing atriums as transit and unifying elements of the urban environment.

## ARCHITECTURE AND CIVIL ENGINEERING

### URBAN PLANNING, PLANNING OF RURAL SETTLEMENTS

Design Algorithm of Urban Bicycle Infrastructure

An algorithm for designing urban cycling infrastructure using sociological, natural and psychological research, spatial multi-criteria evaluation of segments of the road network is presented. The following blocks are distinguished in the body of the algorithm: collection of input data, sociological and psychological research, determination of the existing and planned number of users, spatial multi-criteria assessment of the road network segments, typology of planning decisions, the phased development of the bicycle transport infrastructure. During the application of the algorithm in the design, a high degree of correlation of the results with expert proposals was revealed, which makes it possible to recommend it for use in the design and expansion of the cycle transport infrastructure in cities.

## ENERGY ENGINEERING

### ELECTRIC POWER STATIONS, NETWORKS, AND GRIDS

Transient Processes in the Microgrid Based on a Group of Autonomous Operating Synchronous Generators

The current level of development of power electronics allows the creation of microgrids based on synchronous generators operating at diffrent speeds of rotation of the shaft. The management of energy flows in such networks and the provision of the specified parameters of the generated electricity is carried out using converter devices. The article presents the results of the study of transient processes in the microgrid, in which the energy flows are summed on the DC bus. Simulation of the microgrid is performed using the MATLAB software package with the Simulinlk expansion pack. It is shown that to ensure the stability of the system, it is necessary to carry out an operational correction of the parameters of the automatic controller.

A mathematical model has been developed that adequately describes the complex profile of a high-power single-phase autotransformer tank over 100 MVA. The tangential components of the magnetic field of dispersion on the surfaces of the tank and additional losses of active power from eddy currents in the walls of the tank are determined when the magnetic system of the autotransformer is saturated with direct current flowing through grounded windings. Many of the hottest points of the tank autotransformer are found. The dependence of the maximum values of the rate of change in the temperature of the most heated points on the surface of the tank of the autotransformer AODTSTN-267000/500/220 on the magnitude of the direct current was established.

## ENERGY ENGINEERING

### INDUSTRIAL THERMAL POWER

Design and Study of Exchangers with Pressure Gradient Heat Intensifiers

This paper is presented the numerical study of local heat transfer in the turbulent boundary layer with longitudinal pressure gradient. The study is based to free software with open source code (Salome and Code_Saturne) has been based by RANS approach and empirical models of turbulence. Validation of mathematical models and software is based by collation numerical results with the results of experimental study of flow characteristics in a turbulent boundary layer of longitudinal pressure gradient and high turbulence intensity (Epik E. Ya., NASc of Ukraine). The validation had a high qualitative coincidence of the flow characteristics determined as a result of the simulation with experimental data. We designed two constructive schemes of heat exchangers for air. This study presents a calculation plan for these heat exchangers. Results of the study are showed that the use of gradient heat exchange intensifiers leads to an increase in the heat transfer coefficient from air to 17 %.