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

This article presents the main recommendations for the construction of nodes of solid-wood structures. The basic scheme of the rigid junction of the meridional edges is considered. Based on the results of tests and calculations, conclusions are drawn on the possibility of improving this node. Some recommendations for strengthening the node without increasing the metal capacity of the structure are presented. Several schemes for improving the welded structures are shown. Conclusions are drawn on the possibility of implementing the examples given in the designed structures.

Keywords: Wooden structure, full-size samples, mechanical connections, solid wood, prismatic arch, mounting element, polymer concrete, design model, continuous girder, prefabricated structures

The results of studies of two-layer reinforced concrete beams with a layer of various thicknesses of high-modulus concrete of the frame structure in the compressed zone and traditional heavy concrete in the rest of the section are presented. The stress-strain state of normal cross sections along the height of the beam was estimated by the values of relative deformations at the level of stretched and compressed reinforcement using the hypothesis of flat sections and actual compression and calculated tensile deformation diagrams of concrete. The influence of the thickness of a layer of high-modulus concrete on the nature of the stress-strain state between the layers is shown. The possibility of destruction of the beam on the concrete of the compressed zone was revealed due to the abrupt decrease in the actual height of the compressed zone due to the "shooting" of a layer of high-modulus concrete with its thickness less than 0.1 h0. The dependence of the relative actual thickness of the compressed concrete, i.e. the distance from the edge fiber of the compressed concrete to the neutral axis, in the studied beams on the magnitude of the bending moment is obtained. It is established that for single-layer beams, with a difference in the elastic modulus of concrete up to 20%, the dependences of the relative actual thickness of the compressed concrete layer on the bending moment are almost identical. In the studied beams, the limiting state of which is caused by the fluidity of the reinforcement, the thickness of the compressed concrete layer was 0.37 ...0.4 with a relative moment value of 0.5, and 0.33 ...0.36 with a maximum bending moment value.

Keywords: double-layer reinforced concrete beams, normal cross-sections, nonlinear deformation model, high-modulus concrete, neutral axis coordinate

The article describes the conduct of field studies carried out during the overhaul of the cultural heritage object – the building of MBOU "Gymnasium No. 45" to establish rational parameters of injection of cement-sand mortar, the choice of the type and design of injectors and the scheme of drilling injection wells. It is proved that the technical solutions adopted in the soil fixing project are not optimal and do not provide the required quality of work. Recommendations on technological and constructive solutions for fixing soils have been developed and implemented in practice, taking into account engineering and geological conditions, the results of the survey and fixing at the pilot site.

Keywords: subsidence soil, foundation, cementation, injector, well drilling, geocomposite

The features of the functioning of steel structures in an aggressive environment are considered, the results of a qualitative and quantitative assessment of the nature of damage to a profiled sheet are given.

Keywords: steel structures, building structures, corrosion, aggressive environment, zinc coating, corrosion rate

The technical solution for the construction of local treatment of return drainage flow from an irrigated area, based on the use of ion-exchange filter materials, is proposed. It has been established that the concentration of chemicals in the water of the drainage well is 1/3 lower than in the open collector, where the drainage flow is diverted. Therefore, the localization of the technological unit for the treatment of drainage water relative to the drainage well is a reasonable decision, since it will reduce the financial costs of filter media and the frequency of their replacement. The technological scheme of the treatment plant based on the block principle is described: by disconnecting or connecting individual blocks, it is possible to respond flexibly to changing needs in the quality and degree of drainage water treatment.

Keywords: technical solution, water treatment, ion exchange, drainage flow, block approach, drainage well, water quality, chemical analysis, land reclamation, irrigation system

The thickness of the steel sheets used in the element was gradually increased to meet the load bearing capacity requirements of large span steel bridges. As the main method of joining heavy plate steel, welding results in significant residual welding stresses with a complex distribution. Large residual stress during welding will significantly affect the performance of steel bridges. In this work, the distribution of residual stress in a welded thick steel sheet is systematically investigated, a specimen with a thickness of 80 mm was designed and manufactured, and the residual stress of welding was measured by X-ray diffraction.

Keywords: steel bridge, thick steel plate, welding residual stresses, X-ray diffraction method, weld joint