In article there is considered the application of the finite difference method to plate bending problems. There are done the calculations of simply supported rectangular plate on an elastic foundation by the finite difference method and to verify the results there is done comparison with the results obtained by double trigonometric series. For more accurate results is studied the degree of discretization of the finite difference mesh.
Keywords: finite difference method, plate on an elastic foundation, Winkler model, governing differential equation of the plate, finite difference operator
The article considers the influence of seismic load with different ballistics on aboveground steel gas pipelines of various diameters in areas of possible earthquakes. The change in the proportion of seismic load to the total load acting on gas pipelines during operation is investigated.
Keywords: seismic activity, loads on gas pipelines, analysis of seismic activity, degree of seismic hazard
The article is devoted to the analysis of the possibilities of using modular home building technology. Modular construction is determined by approaches that do not follow traditional methods. The system is reduced to the assembly of prefabricated buildings from individual modules. These modular elements are usually manufactured at the factory. This helps to remove weather restrictions, reduces the risk of a shortage of labor on the spot. Placed on the foundation, the individual modules are assembled into a complete modular structure. With modular housing construction, the possibilities and choices are quite limitless. There is always an opportunity to make an individual design. In prefabricated houses, it is possible to use modules equipped with water supply, sewerage, heating and electricity systems. The article presents an overview of the advantages and disadvantages of the modular design. The advantages are listed in terms of quality, economy, time and ecology, as well as in terms of design flexibility and work safety, both during production and during installation on the construction site. The disadvantages of the modular design are also considered - complex transportation of modules requiring coordination of production and construction, the high cost of production and its typification.
Keywords: architecture, modular housing construction, module, frame buildings, ergonomics, energy efficiency, volumetric and modular design, modular construction
When designing engineering structures, the efficiency of the engineer’s work is important. The cooperation between individual programs in BIM technology is very important in this aspect, because it significantly speeds up the work and, as a result, the design process is less time-consuming. In the process of designing steel structures, the first stage is the selection of an appropriate structural solution, then numerical calculations of the model together with all assigned load cases and dimensioning of individual elements of the structure in terms of the ultimate and serviceability limit state. After selecting the appropriate sections, you can start working on the detailed drawings of a given structure. When performing numerical calculations and drawings, at least two programs should be used. The article presents the cooperation between the Dlubal RFEM numerical calculation program and the Tekla Structures building structure modeling program on the example of a steel structure floor design.
Keywords: BIM, Dlubal RFEM, Tekla Structures, steel structures, direct import, engineering structures
The main maintenance of a diversification of production as activity of subjects of managing is considered. being shown in purchase of the operating enterprises, the organizations of the new enterprises, redistribution of investments in interests of the organization and development of new production on available floor spaces. The most important organizational economic targets of a diversification of management are presented by innovative activity of the industrial enterprise.
Keywords: management, traffic, traffic flows, pedestrian flows, technology, design, interchanges, control method, numerical model, simulation
Based on the research conducted by the authors, data on the stiffness and curvatures of reinforced concrete beams with a layer of various heights of concrete with frame structure are presented. Stiffness, curvature and deflections are given for cases of absence and presence of cracks in the tensile zone of beam. Formulas for describing changes in the stiffness and curvature of sections depending on the magnitude of the moment are obtained. The influence of the thickness of the layer of concrete with frame structure and the diameter of the working reinforcement on the change in the stiffness of the sections is established. The regularity of changing the position of the neutral axis for single and double-layer beams depending on the beam parameters.
Keywords: concrete of frame structure, stiffness, curvature, deflection, layered structures, bending moment, neutral axis
This article discusses various aspects of the design, construction and operation of shopping centers and shopping and entertainment complexes from the point of view of fire safety. Examples of existing structural and space-planning solutions that do not fall under the regulations governing fire safety, but pose a danger to visitors and staff of the shopping center and shopping mall in the event of a fire. Ways to eliminate these shortcomings are proposed.
Keywords: fire safety, children's play area, shopping-entertainment area, normative legal acts
The main reasons for the weakening of wooden structures, as well as the main requirements for strengthening wooden structures, are considered. Various methods for strengthening structures are being analyzed. Strengthening with carbon fiber is highlighted separately, the main advantages and disadvantages of this method are considered.
Keywords: analysis, causes, methods, reinforcement, wooden structures, wood, reconstruction, carbon fiber, composite, strength, deformability
As part of Sol-Iletsky Mine No. 2, it is planned to erect and set up a health resort center for the treatment of respiratory diseases. This health center will provide medical services in the therapeutic salt chambers on the first horizon (123 meters underground). For this purpose, it is necessary to use the waste horizons of rock salt (chamber workings). For the construction of the health-improving complex for safety reasons in part of underground workings, it is required to arrange a fortification. This article deals with mathematical modeling and selection of the optimal type of support for chamber workings.
Keywords: mathematical modeling, stress-strain state, SSS, rock salt, roof support, chamber workings, finite element method, FEM, redevelopment
Effective reinforcement of the coating beam, by means of the construction of a framing frame around it, implies a reasonable choice of a construction from a range of rolled metal. The frame creates a single system with the coating beam by means of tension devices, the change of forces in which provides state control. In the article, a comparative analysis of moments in a frame made of an I-beam and a special steel channel, as having potentially equal performance characteristics, is proposed for a comparative study. The research was carried out on the basis of numerical modeling by the finite element method using the Etabs software product. The result of the experiment was the transverse forces and moments determined in the newly formed system – the coating beam plus the frame – from the applied loads and the percentage of reinforcement of the beam when taking into account the frame. The array of numbers obtained as a result of the numerical experiment was processed by digital mathematical analysis.
Keywords: reinforced concrete beam, I-beam reinforcement, channel reinforcement, moment, percentage of reinforcement, load, numerical method, mathematical model, comparison of results, Etabs and wxMaxima software packages
CFD modeling seems to be one of the most accessible and accurate ways to calculate the characteristics of flow processes using computational and physical-mathematical methods in solving practical problems today. In particular, it is used to determine the parameters of the indoor microclimate. This article describes the process of modeling the operation of hydraulic heated towel rails in the bathroom of a residential building and selects the optimal configuration based on the data obtained as a result of the calculation in the STAR CCM + software package.
Keywords: CFD modeling, building hot water supply, heated towel rail, heat flow, heat transfer, heat transfer, indoor climate, thermal analysis, SolidWorks, STAR CCM+
The formation of the structural form of the roof of trihedral trusses, each of which consists of two inclined flat trusses with a common lower chord, is considered. The design of the spatial truss is made with continuous chords of a closed composite section and a triangular slanting lattice from single rolling corners. The purpose of numerical research of a span trihedral trusses is to assess its stress-strain state with variability of influencing parameters. The methodology of numerical research is based on a calculated mathematical model of a trihedral truss with the application of single loads in the knots and allows you to obtain an array of stress-strain state data, taking into account the variability of the load, which is due to the characteristics of the construction region and the features of the enclosing structure of the roof. The structure of the spatial-stem model is based on a centered geometric scheme. The approbation of the presented methodology was carried out using a trihedral truss spatial-stem calculation model. As a result of numerical research of the proposed technique, data characterizing the stress-strain state of the trihedral truss model from a single nodal load were obtained. The analysis of the obtained results shows that the presented research methodology allows obtaining structured data taking into account the variability of load values and can have practical application of the calculation results in the design.
Keywords: trihedral truss; pentahedral composite profile; direct coupling knot; centered geometric scheme; stem calculation model
The article presents the results of comparative analysis of the equations of Russian and foreign design codes for calculating the web strength capacity of I-beams with steel and fiber reinforced polymer (FRP) transverse reinforcement. It is known that the strength of the web is affected by the properties of the transverse FRP, in particular, its relatively low modulus of elasticity. When calculating the strength of the webl, both homeland and foreign design codes do not distinguish between structures with FRP and steel transverse reinforcement. To assess the accuracy of the equations of the codes, the calculation was performed on a sample made up of the results of our tests and the experiments of other authors. When calculating according to the method of SP 295 and Eurocode 2, overestimated values of the resistance of the web with FRP were obtained. The formulas for the strength of the webs, which give a significant margin when calculating beams with steel transverse reinforcement, also overestimate the resistance of beams for specimens with composite transverse reinforcement
Keywords: wall strength, I-beams, transverse reinforcement, design standards, basalt-composite reinforcement, steel reinforcement
The article provides the basics of the theoretical prerequisites for the question of the reliability of elements of wooden structures, gives the structure that forms the parameters of reliability, formulates criteria for the use of scientific research in the design and calculation of structures using wood. The calculation implementation is presented on the example of calculating the deformability of the enclosing plywood panel of the coating.
Keywords: stress, deflection, elastic modulus, stiffness, load duration fraction, bending, design resistance of wood
The purpose of this article is to conduct a comparative analysis of methods for assessing the technical condition of buildings and structures. The article considers various approaches to assessing the technical condition of buildings and structures, reviews and compares methods, identifies key differences between the foreign approach and the domestic one. The review of methods for assessing the technical condition presented in the article allows us to conclude that a variety of methods can create certain difficulties when choosing and using them. The analysis of domestic and foreign experience has shown that the most popular today are systems for monitoring the technical condition of buildings and structures, involving a set of measures using modern assessment, modeling and forecasting technologies that allow obtaining operational information about the technical condition of buildings.
Keywords: physical wear, operation, technical condition assessment, monitoring, operational qualities, instrumental examination, expert-normative method, cost compensation method
The article considers the work of a reinforced concrete beam lying on an elastic half-plane. The strength of concrete is considered as a random variable, while the initial modulus of elasticity of concrete and, accordingly, the initial stiffness of the beam are taken as functions of the random cubic strength of concrete. The base of the beam is considered as an elastic stochastically inhomogeneous half-plane. Using the method of canonical expansions of random functions, the probabilistic parameters of the probability distribution densities of beam deflections, as well as bending moments and transverse forces in a reinforced concrete beam, which are non-stationary random functions, are obtained. This makes it possible to further determine the probability of occurrence of limit states in a reinforced concrete beam.
Keywords: reinforced concrete beam, initial stiffness, cubic strength, inhomogeneous half-plane, distribution density, beam deflection, random function
The article considers the impact of wind flow on buildings and structures. The analysis of the influence of wind pressure on buildings of various shapes is carried out. The three main effects of wind occurring around wind-sensitive buildings are indicated. A comparison of three building forms was made. It is established that the round shape of the building in the plan has a smaller moment of resistance from wind gusts and from the force of resistance. It is determined that these parameters are higher in the case of square and rectangular buildings.
Keywords: wind, pressure, load, urban ecology, building shape, aeration, urbanization, ecoclimate
The article discusses modern methods for protecting load-bearing structures from progressive collapse, as well as methods for their calculation in extreme conditions, in order to ensure the safety of buildings and structures, reduce material damage and minimize human casualties as a result of emergency situations. The main purpose of the work is to identify the imperfections of existing methods for calculating building structures against progressive collapse, regarding multi-storey residential complexes, which are characterized by girderless frames, which have significant architectural advantages, as well as revealing the inaccuracies of empirical formulas used in practice for determining the coefficients of dynamic strengthening in tension and compression, which entails a calculation that does not correspond to the actual work of structures.
Keywords: beamless frame, progressive collapse, protection measures, calculations, dynamic coefficient, dynamic strengthening coefficient
Currently, artificial intelligence is gaining more and more development in various sectors of the national economy. However, he is not able to function without the control of a person and helps him in solving a narrow range of tasks. In the article, based on the analysis of leaders in the implementation of AI, the prospects for its development are considered. The role of company management in projects for the implementation of AI tools and methods is emphasized. The possibilities of introducing AI methods in the construction industry are considered. It is proposed at the initial stage to apply machine data processing to solve logistics problems. The main stages of the implementation of AI elements for construction organizations are proposed.
Keywords: artificial intelligence, construction, supply, material resources
Co-branding contributes to the creation of more successful products. Purposeful formation of the image of an architectural object, that is, its brand, consists of three parts. Its creation involves the brand of the organization or organizations located in the building, the brand of the author or authors of the project, and the brand of the place. These three components can manifest themselves in different ways in an architectural object. Studying the issues of joint branding of architectural objects and understanding this process is important not only for architects and developers, but also for other professionals. The realization of the possibilities hidden in this area contributes to the creation of a holistic image of an architectural object.
Keywords: building image, place brand, building brand, architecture, co-branding, logo, trademark
This article is devoted to some features of the performance of engineering and technical inspection of chimneys made of brickwork. The relevance of this research topic is due to the presence in our country of a large number of functioning chimneys made of brickwork, whose age exceeds 50 years, while a clear algorithm for performing surveys, taking into account all possible types of defects and features of performing verification calculations of these structures has not yet been developed. The author of the article substantiates the relevance of this research topic, presents the types of defects characteristic of brick chimneys, and also briefly describes the features of performing verification calculations of these structures when performing their engineering and technical surveys.
Keywords: inspection of building structures, exhaust shafts from brickwork, chimneys, brickwork, flaw detection of chimneys, flaw detection of building structures
Mechanical systems oscillate relative to the equilibrium position, and their amplitude depends on both frequency and mass, shape, design and mechanical properties of the system. There are two parameters of the grequency response of mechanical systems: the frequency of their natural vibrations and dynamicity on the effect of forced vibrations (dynamic coefficient). The purpose of the article is to investigate methods for calculating the parameters of the frequency response such a frequency of natural vibrations and the dynamic coefficient of a cantilevered steel beam. The methods which were used are analytical, finite element method with the ANSYS software environment and experimental method on the vibration stand with two loading methods: sinusoidal vibration using the swinging frequency method and broadband random vibration. The obtained natural oscillation frequency values are consistent within the relative error of 15%, dynamic coefficient values are consistent within the relative error of 5%. The finite element method is well consistent with the analytical method, while it requires fewer operations for more complex designs. Differences in the results of experiments arise from differences in the methods of loading the object of research.
Keywords: frequency response, finite element mathod, ANSYS, natural vibrarion frequency, sweep check, broadband random vibration
The application of the gas-dynamic method with the use of nonlinear dynamics to the calculation of an underground structure built into the lower floor on the impact of an air shock wave is considered, taking into account the collapse of the above-ground part of the building. It is known that one of the impacts on built-in underground structures designed to protect the population and territory from natural and man-made emergencies is the impact of a possible collapse or blockage from a higher building when exposed to an air shock wave. This task is relevant because the current methods are based on linear static calculation methods and involve certain assumptions, including when calculating for collapse, and all this can lead to difficult to estimate errors in the calculation results. Therefore, when solving these problems, which are highly non-linear and the processes under consideration themselves are fast, it is necessary to consider the use of more adequate and accurate methods based on more rigorous formulations, which is the gas-dynamic method using nonlinear dynamics.
Keywords: emergency explosive effects, air shock wave, impulse effects, non-linear gas dynamics, compression phase, rarefaction phase, underground structures, “Ambient” elements, Eulerian grids, progressive collapse, collapse of structures, destruction of structure
The article describes four developed designs of samples of joints of solid wood elements on aluminum linings. They made it possible to simulate the operation of real connections of the main and secondary beams, as well as crossbars and columns. Tests of connection samples were carried out, one of the four developed variants of sample designs was selected that most fully reflects the actual work of real joints of wooden elements. The strength and deformation characteristics of the joint, the upper boundary of the elastic work area (VGOUR) of the joint are determined. Based on the conducted research, the peculiarities of the work of the studied compounds were determined, a sample of the connection of a wooden element with a metal overlay was developed, which allowed the development of measures aimed at increasing the bearing capacity and reducing the deformability of the studied compounds without significant material costs associated with the purchase of expensive SHERPA linings.
Keywords: solid wood, metal slips, testing of joint specimens, joint bearing capacity, joint deformability, upper limit of the elastic work region, full deformation, permanent deformation, elastic deformation, safety factor
The article presents the results of the calculation of a steel truss with parallel belts with a span of 36 m for the second group of limit states, taking into account the selected share of the temporary snow load duration. The comparison of the results of determining the vertical displacements of the steel truss structure nodes under the action of permanent and temporary snow loads is carried out.
Keywords: truss, calculated combination of loads, modulus of elasticity, stiffness, fraction of duration, deflection, CAD