The article discusses the possibility of using the ANSYS WORKBENCH software package to calculate the uneven settlement of building foundations. The heterogeneity of the physical and mechanical properties of the soil, the difference in the thickness of the bearing layer and other factors lead to uneven development of settlement. This causes the appearance of cracks in the supporting structures, and in the worst case, the destruction of part of the building or the building as a whole. Methods for calculating settlements are very complex, but using the capabilities of modern computers and computer simulation programs makes it possible to obtain a simple and accurate solution to such problems. To evaluate the deformations of the foundation on heterogeneous soils the ANSYS software package was be used. The proposed method can be used to quantify the uneven settlement of the foundations of real buildings and structures.

Keywords: ANSYS WORKBENCH, foundation, uneven settlement, skew, computer modeling, deformation, finite element method

Steel roof trusses are the main type of load-bearing structures used in the roofing of industrial buildings. Among them, trusses of the “Molodechno” type have become widespread, in which closed bent-welded profiles of square and rectangular cross sections are used as rods. The use of this type of rolled product makes it possible to create structures without gussets and connecting strips, with a maximum degree of process automation, which significantly reduces labor intensity and reduces the cost of their production. Another feature of the coatings under consideration is their non-running solution. The trusses are located in 4m increments, supported by rafter structures. However, in such a situation, the loads on the truss and the forces in the elements are small, and therefore, and also taking into account the limited range of bent-welded profiles, understressing of the truss elements and excessive consumption of metal are likely. Three variants of coatings with different pitches of trusses were considered, and the metal consumption per square meter of coating was determined. It has been proven that with increasing pitch of trusses, the metal consumption of coatings decreases.

Keywords: "Molodechno", rafter truss, sub-rafter truss, continuous purlin, lattice purlin, truss pitch, metal consumption

Studies of a circular cylindrical mesh shell with additional rods and increased rigidity of the supporting ribs were carried out. As part of the search for the optimal design, the criterion of rational material consumption was used. According to the results of the conducted studies, the regularities of the distribution of force factors and deformation parameters were revealed. An assessment of the degree of activity of the work and vulnerability to deformations was carried out. Dangerous areas of surfaces are analyzed, mosaics of forces and displacements are obtained. The contribution of reinforcing elements is determined and the influence of the stiffness of the supporting ribs is revealed. A significant unloading of the spatial structure was achieved and a high level of impact resistance was recorded. A significant decrease in calculated indicators was obtained.

Keywords: cylindrical mesh shell, reinforcement with rods, stiffness of support ribs, optimization, forces, displacements, material consumption

A review of studies of photovoltaic chromatic devices for regulating the transparency of glass and simultaneous generation of electrical energy through an internal photoelectric effect is given. Devices based on thin-film heterostructures with kesterite as a photocell are considered in detail. Kesterite is an absorbing material consisting of copper, tin, zinc, sulfur and selenium, a new promising material for creating "smart" glazing with adjustable transparency. The energy characteristics of coatings based on kesterite are compared with coatings of other types. The prospects of kesterite as a basis for creating effective autonomous photovoltaic windows of adjustable transparency are shown.

Keywords: photoelectric effect, transparency, glass, kesterite, perovskite, silicon, window, energy efficiency, electrochromic effect

The safety of hazardous production facilities is directly related to the reliable operation of pipeline systems, as a failure occurring in the elements of such systems can lead to serious consequences for production facilities and the environment. Since the greatest number of failures is associated with faults caused by corrosion, to increase reliability it is necessary to increase the corrosion resistance of metal of pipeline elements. The article gives an overview of materials for manufacturing parts, the influence of different climatic conditions on the mechanical properties of steels. The developed rotary gate designed for automatic prevention of reverse flow of working medium is also presented. To confirm the serviceability of the design, strength calculation of the structure was carried out, where its stress-strain state under the given loading conditions is considered. As a result, the values of maximum equivalent stresses, maximum deformations and displacements were obtained, which are lower than the maximum permissible ones.

Keywords: pipeline system, pipeline, shut-off valves, swing back gate, mathematical modelling, finite element method

A new building structure is proposed - a welded steel I-beam with a prestressed perforated wall. The prestress in the beam is created by stretching the web and subsequent welding with chords. Before prestressing, holes are cut in the wall. Using the LIRA-SAPR software package, a model is proposed that can be used to study the operation of a prestressed perforated beam (PNPB) structure. The influence of various forms of voids in the wall on the change in the stress-strain state of steel I-beams prestressed by the wall drawing is studied. A preliminary assessment was made of the favorable effect of prestressing in a conventional perforated beam on the stress-strain state of beams with different forms of perforations in the web.

Keywords: steel structures, prestressing, numerical experiment, normal and shear stresses, bearing capacity

The problem of quality in construction and installation works at intermediate stages is being discussed. The role of technical supervision in the construction process is outlined. A proposed indicator, the "Quality Index," is presented for consideration, which reflects not only the quality of the works but also the effectiveness of the technical supervisor's work during the construction process.

Keywords: quality, construction quality, construction quality index, quality coefficient, regulations, technical supervisor engineer

The paper presents the study of the effect of multiple cyclic humidification on the compressive strength across the grain edgewise of laminated veneer lumber (LVL), long-term sustained in conditions with high humidity. A significant decrease in its strength properties during cyclic humidification (up to 18% in three cycles) has been proved. The dynamics of crack growth due to the influence of the humidity factor is given.

Keywords: laminated veneer lumber, timber structures, strength, cyclic dampening, drying cracks, hygrostalness

This article defines the necessary characteristics of the collapse of a group of 10 vertical steel tanks with volumes of 15,000 and 20,000 m3

Keywords: oil industry, petroleum products, accidents, vertical steel tanks, collapse

The article discusses modern approaches to the calculation of embedded parts using the most common computing systems in the design environment. The main purpose of the work is a comparative analysis of the stress-strain state of the support plates and anchor rods when calculating in various computing complexes in order to obtain the most reliable and complete results necessary for the designer to ensure reliability when designing components of building structures. In addition to the above, the article focuses on ensuring the rigidity of the support plates, in case of compliance with which, the nodal structural element is able to withstand a single impulse impact.

Keywords: computing complexes, embedded parts, calculation methods, calculation situations, dynamic coefficient, strength indicators

The paper presents a method for calculating the stress-strain state of composite metal-wood beams, taking into account the compliance of bonds in a nonlinear setting using the SCAD software. In the course of the calculation, the pattern of stress and strain distribution, which is close to the real one, was determined. The concentrations of stresses that are capable of initiating the destruction of the structure are determined. Dangerous areas have been identified that make it possible to predict the mode of destruction of the structure, in order to organize measures to strengthen it. The results of the numerical experiment are confirmed by the materials of physical tests.

Keywords: wooden structure, composite beam, pliable connection, calculation, finite element method, stress-strain state, connection, metal-wood beam

The paper presents a study of the water resistance of joints of load-bearing laminated timber structures using domestic melamine-urea-formaldehyde adhesives (MMFC). The high relative strength of samples dried after soaking and boiling above that established for the increased water resistance group is shown. An assessment of water resistance for three formulations is given, the dynamics of crack growth due to the influence of the moisture factor of MMFC.

Keywords: melamine-urea-formaldehyde adhesives, wooden structures, water resistance of adhesive joints, strength

To create composite building materials with a polymer matrix, various fillers of both plant (wood-polymer composites - WPC) and mineral (mineral-polymer composites - MPC) origin can be used. The article evaluates the feasibility of using twelve different minerals in MPC from the standpoint of strength, cost and weight of the resulting materials in comparison with similar indicators of WPC. By sequentially considering each of the evaluated parameters, the sample of fillers is reduced by excluding combinations with characteristics worse than those of the reference material - a wood-polymer binary composite consisting of wood flour and polypropylene. It has been shown that one of the most effective mineral fillers can be waste from construction industry enterprises, as well as structures recycled during the demolition of buildings and structures.

Keywords: composite, matrix, filler, mineral, wood flour, dust, cost, volumetric weight, strength, elastic modulus, Poisson's ratio

The process of determining the most effective design solution from the point of view of metal consumption for the dome structure of the designed exhibition complex in Rostov-on-Don with a plan diameter of 100 m is considered. Three different dome design options are analyzed. Calculation models were created in the Lira-SAPR software package and calculations of various coating options were performed. The obtained results were compared in terms of rigidity and conclusions were drawn about the possibility and feasibility of using each of the considered design solutions. The most efficient design option in terms of metal consumption was selected.

Keywords: metal structures, dome, metal consumption, material consumption

The provisions on the choice of vehicles for the transportation of prefabricated reinforced concrete structures are considered. Transportation can be carried out using general-purpose and specialized vehicles. The existing rules for loading onto road transport are aimed at eliminating the formation of defects in structures. For loading onto vehicles in structures, various devices for slinging are used - mounting loops, holes, or other elements provided for by working drawings for specific structures. Ensuring the safety of transported structures is possible only when studying the complex system "road - vehicle - transported structures". Factors that should be taken into account when calculating for transport effects: type of product (columns, slabs, panels, etc.) and its design features; type of vehicle (column carrier, panel carrier, etc.) with its characteristics; type of road and speed of transportation.

Keywords: transportation, road transport, loading, precast concrete, slab, truss, column, beam

The article is devoted to the topic of secondary use of oil industry waste, namely drilling mud, as an additive in the production of building bricks. In the article, the most used methods of drilling mud processing in the oil production industry are discussed. To date, there is no ecologically effective method of processing, utilization and neutralization of drilling waste. Processing technologies that involve the use of drilling waste as secondary raw materials are gaining popularity, but are not fully developed. Special attention in the article is devoted to consideration of the use of drilling mud waste as a secondary raw material. The laboratory studies of the application of drilling mud in the production of ceramic bricks are presented, the main purpose of which is to reduce the negative impact on the environment, reduce the costs of transportation, storage, processing of drilling waste, as well as the economy of natural resources.

Keywords: drilling, oil industry waste, drill cuttings, sludge pits, negative impact on the environment, recycling, secondary resource, component composition, construction

The transitional type of pavement of highways is widespread in Russia. At the same time, the increased estimated time between repairs cannot be fully ensured by the adoption of existing design solutions for the installation of transitional pavement pavements. This is confirmed by the dynamics of changes in the operational state, presented on the example of the road of regional importance Birakan - Kuldur in the section km 0+000 - km 25+000 in the Jewish Autonomous Region. Non-failure operation during the estimated overhaul and estimated service life of the pavement is assessed by the destruction coefficient, the limit values of which are set in the regulatory documentation. A significant decrease in the pavement destruction coefficient during the first few years of operation indicates insufficient strength and stability of the transition pavement pavement, which determines the need to develop special measures to ensure them.

Keywords: road, pavement, transitional type of pavement, pavement, destruction coefficient, overhaul life, longitudinal evenness, strength

Construction control at the stage of preparation for the commissioning of the object requires checking the quality of external enclosing structures according to the air permeability parameter. The GOST 31167 methodology available to specialists, as well as other similar methods, is based on the principle of creating and maintaining the required pressure drop in the room and beyond its boundary for a long time while simultaneously determining the flow rate of the air supplied for testing. The essence of this method is that it limits the possibility of quantifying the values of air permeability through specific sections of external enclosing structures and allows you to determine only complex indicators for one room or a group of rooms without specifying specific values of defects in various types of exterior walls, window fillings, door openings, and abutments. The proposed method of qualitative and quantitative assessment of air permeability is based on an additional analysis of the temperature fields of the internal surfaces of external enclosing structures while ensuring a given difference in pressure and temperature of the indoor and outdoor air entering the room by creating a vacuum. Conducting field studies is necessarily complemented by the results of numerical modeling of structures in undisturbed and defective states.

Keywords: non-stationary heat transfer, numerical modeling, calculation of temperatures in the defect region, analysis of temperature fields, air permeability resistance, experimental evaluation of air permeability

The comparison of technological settlement values during the construction of various variants of diaphragm wall is presented. Numerical modeling of the construction of a diaphragm wall enclosure was performed in weak water-saturated clayey soils using the Plaxis 3D software package. The investigation results revealed that the technological settlement of the building foundation caused by constructing a trench-type diaphragm wall significantly exceeds the values observed in the construction of a diaphragm wall with augered piles.

Keywords: technological settlement, excavation enclosure, diaphragm wall, numerical modeling, Plaxis

The article presents the results of a study of the use of reinforcement in glued wooden elements of a circular mesh vault. The use of reinforcement in flat wooden structures has proven itself well, but the possibility of using reinforcement in large-span spatial structures still remains little explored. A number of authors presented conflicting data regarding the increase in the bearing capacity and rigidity of reinforced wooden glued elements. In the proposed work, a numerical experiment was performed to compare various options for reinforcing elements of a circular mesh vault. 10 options for external and internal reinforcement of elements with various materials were considered. As a result of the analysis of the stress distribution in the section of the elements, it was revealed that external reinforcement is a more priority method of reinforcement in terms of the stress-strain state of the element. The dependences of the deflection on the height of the section and the area of the reinforcement were determined. The most appropriate solution in terms of material consumption, economic efficiency and corrosion resistance is internal reinforcement with carbon composite reinforcement.

Keywords: Circular mesh vault, glued timber, wood reinforcement, FRP, external reinforcement, numerical stress analysis, economic efficiency of reinforcement

When solving the problem of ensuring the mechanical safety of buildings and structures according to GOST 27551-2014 “Reliability of building structures and foundations. Basic provisions” it is allowed to apply a risk-oriented approach. A mandatory stage of this approach is the forecast of the expected accident risk situation of the facility. Due to the fact that the current regulatory documents on risks do not reflect all the features of the stress-strain state of building structures and foundations of buildings and structures during the operation of structures and, therefore, do not allow for a sufficiently accurate assessment of the safety of structural systems, risk assessment for building structures is a very relevant scientific and technical problem.

Keywords: building, building structures, design, destruction, safety, accident risk, risk assessment, risk management, monitoring and risk analysis

The article deals with the application of load-bearing and enclosing structures made of glued wood for multi-storey, including residential, buildings. Introduction. The relevance of the construction of wooden multi-storey buildings is confirmed by quite a large experience of construction abroad. Also, there is an increasing interest in this industry in Russia at present. Theoretical numerical study and technical and economic evaluation of the results. The stress-strain state and technical and economic indicators of three structural schemes of the building are analysed in the proposed work on the basis of the theoretical study: frame scheme - full frame with bearing columns, floor and roof beams; combined structural scheme - vertical bearing elements are wooden columns, glued wooden panel is used as floor and roof; frameless structural scheme - all the structural elements are made of glued wooden panels. Conclusions. As a result, the most rational and economically favourable structural solution of a multi-storey building made of glued wooden elements has been obtained.

Keywords: glued timber structures, wooden multi-storey building, structural design, economic efficiency, stress-strain state

This work is a continuation of a scientific study to determine the effectiveness of composite materials based on carbon fabric in the field of strengthening bending and compressed elements. The article is devoted to the determination of the geometric characteristics of prototypes, the description of the structure of the internal metal frame and the methodology for strengthening reinforced concrete samples. The importance of this scientific work lies in the fact that one of the most popular companies selling composite materials in Russia (“Gidrozo”) proposes to use a new technology for reinforcing reinforced concrete structures that differs from that recommended in the norms. However, according to the manufacturer's specialists, this technique not only ensures reliable adhesion and joint operation of reinforcement materials and structural concrete, but also significantly increases the efficiency of the composite material.

Keywords: steel, heavy concrete, reinforced concrete, composite material, reinforcement, carbon fiber, test, stand, beam, sample

No modern metropolis can be imagined without such public transport as the subway. The subway is the most important element of infrastructure for large cities and provides a convenient, fast, safe and environmentally friendly way for the population to travel. The construction of the subway is a long and complex process, which requires large investments and consideration of many factors. During the construction of metro stations it is necessary to carry out work on laying utilities, such as electric cables, pipelines for water supply, sewerage, ventilation and other systems. These utilities ensure the operation of the stations and comfort for passengers. Erection of engineering networks in the subway is a complex and multi-year process that requires application of new technologies and high qualification of specialists. However, proper planning and work coordination can significantly reduce time and costs of the project, ensuring uninterrupted operation of metro stations in the future. The work is devoted to the peculiarities of construction of the Moscow subway, which is considered one of the largest subways in the world in terms of length and passenger traffic.

Keywords: metro, utilities, high voltage cable, ventilation shaft, tunnel fan

The influence of the location of reinforcing bonds on the general condition of cylindrical mesh shells is investigated. Cruciform core elements made of tubular profiles were used as reinforcing structures. The number of reinforcing elements is 8 (4 on each panel). Opposite nodes of adjacent faces are connected by cross-shaped elements in the direction of the arc. The expediency of placing reinforcement elements inside each of the two middle panels and at a distance of one panel from the middle of the length is checked. As a result of the conducted studies, the regularities of the stress-strain state and dangerous areas of the shell were determined. When using cruciform joints, a decrease in the forces in the elements and a decrease in the movements of the nodes were revealed. A redistribution of internal force factors and a decrease in the number of typical sizes of elements were recorded. A rational scheme of reinforcement of the structure is obtained.

Keywords: cylindrical mesh shell, reinforcement, cross-shaped elements, forces, displacements