The article analyzes the survey results of standard curtain walls with air space (hereinafter – CWs), used in construction industry in the city of Moscow. Despite a large number of advantages, curtain wall ventilated systems have a number of disadvantages, resulting, on the one hand, from the design solution of the CW: heterogeneity, shrinkage and deformation of the insulation layers, water penetration through the lining cracks, etc. On the other hand, failure to meet the CW technology and insufficient development of regulatory support for the design, installation and maintenance of CWs lead to a decrease in their quality. For a number of survey objects, a discrepancy between design and technical solutions was revealed: for the material of the supporting structures; for the material of the brackets; for the material of self-tapping screws; for the material of facing plates. Based on the survey results, it was revealed that it is inappropriate to use facing elements made of fiber cement boards in order to prevent their collapse and ensure the safety of people near the wall systems. Also, it is not advisable to use ""TYVEK House Wrap"" (1060) wind and hydroprotective membranes for installation from the outer surface of the thermal insulation of buildings due to their fire hazard.
Keywords: hinged facade systems, ventilated, facing plates, fasteners, defects, testing, displacement, cracks, chipping, deformation
The results obtained during experimental studies of deflections of reinforced concrete struts of two flexibilities λh = 10 and 20 tested at three load application eccentricities e0=0; 2.0cm (0.16h) and 4.0cm (0.32h) are considered.Theoretical calculations of deflections were performed according to the current set of rules (SP 63.13330.2018). Based on experimental data and calculation results, it was found that the values of theoretical deflections differ significantly from experimental ones. The influence of the eccentricity of the load application and the flexibility of the samples on the convergence of the theoretical and experimental values of the deflections of the images was analyzed, possible causes of the discrepancy were considered and proposals for improving the calculation methodology were developed.
Keywords: "concrete, reinforced concrete, compressed elements, flexibility, eccentricity, the second group of limit states, deflection "
The article is devoted to the actual problem of automating the life support processes of the system “intelligent building”, through the introduction of telemetry modules, in order to comply with the requirements of high-quality supervision, control and precautionary measures, in particular, in the areas of maintenance of water networks, responsibility for the operation of engineering networks and facilities between suppliers and consumers, ensuring water quality analysis. An analysis of the automated dispatching control and management system (on the example a water intake unit) shows that a lot of works (both Russian and foreign researchers) are devoted to the issues of control and distribution of water supply in the city, but narrowing the object of study to a complex of an automated sodium hypochlorite dosing system, the possibility of its optimization, taking into account the specific states of the system. The formulas given in the work for calculating the working dose and the amount of active chlorine, well as the number of strokes the dispenser pumps and the formulas for determining the actual working dose of the disinfection process, open up the possibility of clearly monitoring the actual dose and adjusting it, analyzing in detail the main parameters of the disinfection system. At the same time, the automatic control of the complex is carried out by a controller and PC, and the relevance lies in the use of telemetry control modules for organizing uninterrupted, remote operation of the dispatch service. Thanks to telemetric means of dispatching control and management of the state of water supply facilities, the process reaches a new qualitative level. The functionality of the water intake unit is expanding due to the introduction of telemetry and telecontrol system in the form of separate technological modules. The developed modules (through spatial and time series models) provide the performance of additional functions, such as: water quality control (residual chlorine, accounting for a number of random pollution factors), support for the route technology of the dispatching system, remote control of actuators with the possibility of automatic control, self-diagnostics of the software and hardware complex, as well as planning preventive measures. repair and restoration works of engineering systems. As a result of operational monitoring of water quality (using a telemetry module), optimal ratios of chlorine entering the water are automatically provided in the chlorination room. At the same time, the author convincingly proves that the use of the proposed method for monitoring and transmitting data makes it possible to perform continuous remote diagnostics (of communication channels, the performance of all systems) and, importantly, there is no need to send specialists directly to the object each time (parameterization and calibration of devices is carried out remotely). Quick setting of limit levels and modes of operation allows you to flexibly control the production process, reconfigure it according to changing tasks and re-equip it (if necessary).
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
Тhe article provides a detailed analysis of the work under load structures of clamp scaffolding and systematizes the features of taking into account loads and impacts when performing strength calculations. The article analyzes the stress-strain state of free-standing forests. An algorithm for calculating free-standing forests is proposed, taking into account the features of structural schemes of blocks that are not specified in the normative literature. Based on the results of the analysis of data from a series of numerical experiments, constructive measures are proposed to ensure the load-bearing capacity, rigidity and stability against overturning of spatial blocks of free-standing forests, which will allow installing blocks with a height-to-size ratio exceeding 3,5:1 in open areas (outside buildings and structures) without attachment to existing structures.
Keywords: steel scaffolding, yoke scaffolding, stress-strain state, structural solutions, stability, load-bearing capacity, nonlinear calculation, spatial free-standing block, dismounting, off-center coupling of elements
The work of reinforced concrete racks made of concrete frame structure is analyzed. The conclusion is made about the expediency of using concrete frame structure in reinforced concrete columns.
Keywords: concrete frame structure
The article discusses the areas and prospects for the use of low-poly geometric models in the construction industry. Data on foreign researches in the considered area are given. The main differences of this type of models from the three-dimensional components of information models are listed, the difference in the methods of their development is described. An analysis of the currently relevant areas of application of these models in the construction industry was carried out, the key features that models should have to use them in these areas are named.
Keywords: civil engineering, low-polygon models, architectural and urban planning solutions, virtual reality, 3D cadastre, geoinformation systems
The article is devoted to the study of curves that are not representable by the intersection of two surfaces. In modern architectural practice, they very often depart from classical forms, replacing them with complex surfaces. Recently, there has been the development of such an architectural style as architectural bionics or bio-tech. Faced with the challenges of sustainable development and its impact on the environment, the construction sector faces the necessary need for innovation. Architecture is presented as one of the promising areas of knowledge use based on biological research. And it is able to respond to current environmental problems. Indeed, many species of animals and plants know how to apply adaptation strategies to the environment and its transformations, forming together with it a sustainable ecosystem. Technological advances in very small-scale observation allow for deeper knowledge of how nature works and offer a new source of knowledge and inspiration for architecture.
Keywords: architecture, spatial curves, axonometric projections of curves, narrowed curves, bionics, biomimicry, eco-innovation
The exploited roof is intended for use, for example, as a recreation area, sports grounds, landscaping, parking lots, etc. It is proposed to compensate for the shortage of urban areas and the high cost of land within the city by using the concept of vertical construction expansion. The lack of free open space limits the ability to accommodate the necessary infrastructure to serve the growing number of residents and reduces the level of comfort for living. The article presents the results of a comparative study of technologies for the installation of operated roofs, arranged with a traditional and inverse arrangement of a waterproofing carpet and thermal insulation. As a result of the study, the technological advantages of the installation of an inverted exploitable roof intended for landscaping are shown. The labour intensity of technological operations and the duration of work when installing a green roof using inversion technology is 19.5% lower compared to the traditional one.
Keywords: exploited roof, vertical gardening, inversion roof technologies
The article proposes a technique for optimizing trihedral lattice tower structures according to the criterion of minimum mass, taking into account limitations in strength, ultimate slenderness of elements, stability, and the absence of resonant vortex excitation. A lattice tower with a cross section of elements in the form of round pipes, consisting of two sections, is considered. The variable parameters are the width of the tower, the height of the lower section, the outer diameters of the cross-section of the chords and gratings, the number of panels in the lower and upper sections. The solution of the nonlinear optimization problem is performed in the MATLAB environment using the Global Optimization Toolbox package. Determination of forces in the tower and frequencies of natural oscillations is performed by the finite element method using the subroutine for MATLAB developed by the authors. The influences on the tower are ice and wind loads, the dead weight of the tower, as well as the weight of the equipment. When calculating the effect of wind, the pulsation component is taken into account. The surrogate optimization method is used to solve the nonlinear optimization problem. In the initial approximation, the mass of the tower was 2 tons. As a result of optimization, the mass was reduced by more than 2 times.
Keywords: lattice towers, finite element method, surrogate optimization, resonant vortex excitation
The paper considers theoretical studies of the deformed state of the nagel joint with claw washers in LVL structures (from the English LVL – Laminated Veneer Lumber). A mathematical model of snow load has been developed. The method of theoretical calculations of creep from the action of periodic load on the basis of previously performed experiments is given.
Keywords: claw washer, LVL, connection, deformation, mathematical model, load, regression equation, humidity, creep
The regulation of the stress-strain state of the floor slab is considered in order to choose the optimal design solution for the frame of a unique building. Three variants of design solutions with varying reinforcement of the plate and cross sections of the vertical elements of the frame are proposed. The numerical experiment was performed by the finite element method using the Lira-CAD software package. To improve the accuracy of the results obtained, calculations were made taking into account the nonlinear operation of materials. The computational model of the floor slab includes physically nonlinear shell finite elements. Nonlinear loading was modeled taking into account the creep of concrete. Based on the results of the calculations, the analysis of the deflections of the floor slab and the consumption of materials was performed. The numerical experiment allowed us to propose an optimal design solution for the frame of a unique building.
Keywords: stress-strain state, finite element method, unique building, physical nonlinearity, deformation law, building frame
A step-by-step finite element method calculation algorithm of concrete filled steel tubes is provided with an example. A comparison of the finite element calculation results with experimental data, calculations according to Russian (SP266.13 25800.2016) and European standards (Eurocode 4) and the “inverse” numerical-analytical method, which takes into account the actual rigidity of sections, is given as well. The study shows an accuracy of the proposed finite element model using Drucker-Prager model for concrete and the “inverse” numerical-analytical method in comparison with standard calculation methods.
Keywords: finite element method, concrete filled steel tubes, Drucker-Prager model, “inverse” numerical-analytical method, eccentric load
Energy saving and energy efficiency is one of the priorities of the state policy of the Russian Federation and, in particular, the Stavropol Territory. This article analyzes the current state of energy efficiency of construction facilities in the Stavropol Territory. There is a discrepancy between the technical condition and functional and consumer qualities of industrial and civil buildings to the current thermal engineering standards. From this point of view, the chosen research topic may be very timely and relevant. The problem of increasing energy efficiency depends on solving the issue of energy saving in the design, construction and operation of buildings. Saving energy consumption is one of the most important tasks in the construction, reconstruction and operation of buildings and structures of the Stavropol Territory. The article presents regulatory sources used for analysis and recommendations on energy efficiency of buildings. The conditions for carrying out measures to improve energy efficiency in the cities of the Stavropol Territory are analyzed, cities that have received significant savings due to the introduction of energy-efficient measures are highlighted.
Keywords: construction, construction technologies, industrial and civil buildings, energy saving, thermal protection of buildings, energy efficient technologies, construction industry, Stavropol Territory
The article presents the results of experimental studies of the operation of mobile wood and metal-wood road pavement and work sites. The results allow to predict with sufficient confidence the stress-strain state of mobile road pavements in real conditions of operation ground as temporary roads, helicopter pads and drilling rig sites.
Keywords: mobile road pavement, demountable plate, temporary roads, static load testing
The process of optimizing the applied sections in steel frames with elements of variable stiffness, formed from rolled I-beams by their diagonal dissolution and subsequent welding, is considered. A table with groups of I-beams according to GOST R 57837-2017 is proposed, which are advisable to be used together to form a monosymmetrical I-beam of variable height. An algorithm for finding the optimal section is proposed, taking into account the discreteness of the assortment. The calculation of a typical building structure code 828KM according to the proposed algorithm is carried out and a comparative analysis of the applied sections with the found optimized sections is presented. The possibility of obtaining a more economical supporting structure, both in terms of metal consumption and in terms of the cost of rolled products, is noted.
Keywords: variable section, variable stiffness, diagonal opening, I-beam, steel frame
The article considers the possibility of increasing the resistance in sulfate environments of concrete composites based on cement raw mixtures modified with a slag mineral component and a complex superplasticizer. The method of research and modeling of the nature of the impact of an aggressive environment on composites proves the prospects of the technology of chemicalization of cement concretes for the manufacture of durable building structures based on them.
Keywords: sulfate environment, cement concrete, corrosion resistance, chemicalization, composite, environmental impact modeling
The unique building of the Center for Science and Art is modeled as a variant of the complex development of the territory of the old hippodrome in Rostov-on-Don. The analysis of the formation of vertical external communication parametric structures for a spherical object is performed. Based on the results of the consideration of ten forms, a rational form of "Turban" was determined, which retains a constant comfortable slope, and in emergency situations can go into autonomous mode while maintaining the rigidity of the structure. Visualization of the object's integration into the urban environment was carried out in Rhino 3D using the Grasshopper visual programming language program. By combining specialized years, modeling of roads and the volumetric geometry of buildings, the object of study, zoning and reading information from the surrounding area was carried out. The resulting model allows us to evaluate the aesthetics and comfort of the urban environment in the case of construction of a new facility.
Keywords: unique buildings, modeling, parametric architecture, urban environment, grasshopper
The article discusses the geological aspects of the existing and designed anti-landslide protection system of the central part of the Karasan landslide on the Crimean peninsula, where the reconstructed Oryol boarding house is located.
Keywords: landslide, anti-landslide protection system, pile protection wall, retaining wall, Crimea, reconstruction, bored piles
The article substantiates the effectiveness of the design and construction of terraced houses for building slopes as a solution to the problem of a limited amount of land and preserving the originality of national architecture. Architectural and planning solutions for terraced-blocked residential buildings for construction on the territory of the Kabardino-Balkarian Republic are proposed.
Keywords: Residential building, terraced building, complex relief, architectural appearance, block house, social need, national architecture
the article deals with the issues of anchoring external composite reinforcement. The advantages of one of the reinforcement options are described - with the help of anchor harnesses. The procedure for performing work when reinforcing with anchor harnesses is presented. Also presented is a method for calculating pull-out anchors made of carbon fibers.
Keywords: reinforced concrete, concrete, composite materials, carbon fiber, reinforcement, external reinforcement, composite anchor
The article discusses solutions to eliminate obsolescence of the Abakan Hotel, while preserving the historical appearance of the building. The main distinguishing features of the architectural image of the hotel are considered, examples of eliminating moral (functional wear) are given: replacement of wooden floors with monolithic reinforced concrete, arrangement of cores, creation of a frame frame in a docked block, creation of a basement floor instead of existing floors on the ground. Objects with the use of similar design solutions are considered. A variant of reconstruction with an attic floor superstructure is proposed.
Keywords: reconstruction, strengthening, Stalin's Empire style, attic floor, preservation of the architectural appearance, seismic impact