The coatings construction of buildings and structures in the form of wooden shallow shells on a rectangular plan are considered. The orthotropic of the material and the geometric nonlinearity of the thin-walled structure taken into account in the equations. The Bubnov-Galerkin method is used to solve differential equations of wooden shallow shells with different supports. The influences of the ratio of elasticity in mutually perpendicular directions, shape and thickness of a structure on the value of stresses, critical load and low frequencies of small values of vibrations are investigated. The investigations results are given in dimensionless form and graphs are shown. This makes them useful in engineering calculations. Recommendations for adjusting the shape and thickness of the structure of coatings in the form of shallow shells to increase their bearing capacity or reduce material consumption are given.

A variant of the crack resistance criterion and the strength criterion of plane-stressed structures made of high-strength fiber-reinforced concrete, fiber-reinforced concrete is proposed. The criteria are based on the theory of plasticity of concrete and reinforced concrete G.A. Genieva. In general, the condition for crack resistance of a plane-stressed fiber-reinforced concrete element is presented in the form of an ellipse with jumps on the coordinate axes of the main reduced stresses. The strength condition of a fiber-reinforced concrete element is described by a complex figure that takes into account cracking in the element under a plane stress state. The characteristic points on the coordinate axes are calculated from the physical and mechanical characteristics of concrete strength, obtained as a result of testing high-strength fiber-reinforced concrete for uniaxial compression and uniaxial tension with “dissolved” fiber in the concrete body and reinforcement reduced to concrete. The results of a comparative analysis of the criteria for crack resistance and strength of high-strength concrete and high-strength fiber-reinforced concrete are given, depending on the percentage of fiber in the concrete body and the type of fiber used. The proposed analytical dependences can be used to analyze the crack resistance and strength of plane-stressed reinforced concrete beams-walls reinforced with fiber, corner zones of shallow shells and other plane-stressed structures made of high-strength fiber-reinforced concrete and fiber-reinforced concrete.

The moments in reinforced concrete during bending with torsion were determined, the new first hypothesis of linear deformations and its filling of the diagram during bending with torsion for the analytical second functional as a function of three functions - an exponent, a straight line and a parabola curve. A simple new method is found (from the family of mesh methods) and a summed function of additional deplanation is proposed. The new second hypothesis of angular deformations and its filling of the diagram in reinforced concrete during bending with torsion is constructed. The analytical first general undefined functional is a function of functions, as well as transitions, operations between functions. At the same time, a spatial triple integral of arguments from longitudinal deformations for the first hypothesis was obtained, as well as the third and fourth functionals (indefinite and definite) from moments (bending and twisting) with the projection of the coefficients of the diagram of "deformations - stresses" of compressed concrete and the filling coefficients of the diagrams of compressed concrete for their shoulders to the neutral axis for a field of small squares. The bending and torque moments from the compressed area of concrete and working reinforcement are determined (folded for their levels or expanded into algebraic functions from the synthesis of the computational model of reinforced concrete blocks). In this case, we have new functionals (from the first to the fourth functional), proposed hypotheses (first and second), as well as cross sections (from small squares) to a spatial crack. There are also jumps (cracks) lateral, normal, etc., from the first - third stage of average deformations of concrete and working reinforcement.

Shear-free theory of V.Z. Vlasov remains one of the most reasonable approaches to calculating thin-walled bars taking into account constrained torsion. At the same time, the use of this theory for the analysis of deformations of frame structures still requires research in terms of the conditions for transferring forces in bar connections. As noted in some scientific papers, the balance of bimoments can be significantly broken at the joints of thin-walled bars of an open profile in some designs. This paper deals with thisphenomenonfor steel I-beam profiles, associated with thepresence of inclined stiffeners in joint units. Using shell finite element models,the influence of inclined stiffeners on the appearance of bimoment jumps at the pairwise connection of bars is shown. A dependence is derived that makes it possible to take into account the stiffness of the inclined edge in the bar models from the point of view of the restraint of cross-section warping. On the basis of numerical experiments, it was determined that the introduction of such stiffness into the bar finite element schemes of frame structures allows to reflect the condition of bars interaction in the transferringof bimoments with a sufficiently high accuracy for engineering practice.

Textile concrete is an innovative composite material that has been the subject of intensive research since the beginning of the 90s of the last century. After the approval of the rules and regulations on its application to strengthen floor slabs, an important step was taken towards its entry into the building materials market. Questions regarding the reinforcement of rod-shaped load-bearing elements of building structures need additional research. Despite the great potential available, the method of tying load-bearing supports and columns is still not well understood. There is a need for research on a wide range of geometric parameters and the reinforcement systems used. The Institute of Reinforced Concrete of the Higher Technical School in Leipzig tested various samples of carbon-reinforced samples in a wide range of geometrical parameters. Their goal was to assess the effect on a possible increase in the bearing capacity of carbon-reinforced columns at a concentrated point load.

The paper presents a method of using the reduction factor to ensure the stability of monolithic reinforced concrete bearing structures to progressive collapse. Within the framework of the verification study, the correctness and validity of the developed method for the computational analysis of monolithic reinforced concrete bearing systems of buildings and structures to resist progressive collapse were proved. The reduction factor (K1) obtained and justified in the framework of the research performed is the most important deformation characteristic of the special limiting state of monolithic reinforced concrete bearing systems of buildings and structures for an emergency design situation associated with the failure of a local structural element.

During the entire life cycle, the facilities are experienced to force and environmental actions of various nature and intensity. In some cases, such influences can lead to a loss of the bearing capacity of the structural elements of a building, which in turn can lead to a disproportionate failure of the entire structural system. Such phenomenon was called progressive collapse. Major accidents at facilities, such as the collapse of a section of the Ronan Point high-rise residential building (London, 1968), the Sampoong department store (Seoul, 1995), the Transvaal Park pavement (Moscow, 2004), the World Trade Center (New York, 2011) and others, clearly demonstrated the urgency of this problem. In this regard, the regulatory documents of the USA, Great Britain, EU, China, Australia, Russia and other countries established requirements for the need to calculate structural systems of buildings for resist to progressive collapse after sudden localized structural damage. However, the steady increase in the number of new publications on the problem of progressive collapse observed in the world scientific literature indicates that the results of such studies do not yet provide exhaustive answers to all questions related to this phenomenon. In this regard, the proposed review article is aimed at systematizing, generalizing and analyzing new research results on resistance to progressive collapse of facilities, identifying new trends and proposing new research directions and tasks to improve the level of structural safety of design solutions for buildings and structures. In order to achieve this goal, the following aspects were considered: the nature of the impacts leading to progressive collapse; features of modeling the progressive collapse of structural systems of buildings and structures; mechanisms of resistance to progressive collapse and criteria for evaluation of a progressive collapse resistance. Particular attention in the scientific review is paid to the analysis of works related to a new direction of research in the area under consideration, associated with the assessment of the bearing capacity of eccentrically compressed elements of structural systems, the effect on their resistance to progressive collapse of the parameters of the loading mode, degradation of material properties and the topology of the structural system. The significance of the proposed scientific review is that, along with the well-known and new results presented in the English-language scientific literature, it summarizes and analyzes the original approaches, methods and research results published in Russian-language scientific publications, primarily included in the RSCI Web of Science.

The study is based on little-known factual material: a comprehensive analysis of documentary and printed sources of central and regional archives, museums and libraries; family domestic and foreign archives; a full-scale survey of the preserved fragments of the Korennaya Pustyn settlement. The scientific novelty of the research is connected with the author's expeditions and surveys of the development complex of the village of Korennaya Pustyn (monastery, fair, village) (measurements, photo-fixation, full-scale sketches), archival and printed sources that resurrect images of lost noble and merchant estates of dachas are identified, and a general analysis of the given topic is carried out. An important result of the study is the disclosure of the phenomenon of country estate construction of the Kursk province settlement as part of the monastery and fair complex of the town of Korennaya Pustyn in the 2nd half of the XVIII - 1st half of the XIX centuries.. The paper considers the features of stylistic stages and spatial planning solutions in the architecture of the ensemble of buildings and structures of a unique settlement. The research was carried out at the expense of the State Program of the Russian Federation "Development of Science and Technology" within the framework of the Plan of Basic Scientific Research of the Ministry of Construction of the Russian Federation and the RAASN.

The objectives of the study were the questions of the prerequisites for the renovation of the coastal territory of Volgograd for the formation of sustainable development of the territories of the Volgograd agglomeration. The article presents the results of an urban planning analysis: functional zoning of the embankment territory; a scheme for the reorganization of the territory within the boundaries of the concept development; a scheme for the classification of green areas and retrospective material. The article substantiates the relevance of the development of urban recreational spaces, coastal areas, transformation and modernization of existing buildings in the context of solving the problems of urban development. The requirements for evaluation for each characteristic indicator that affects the transformation of the existing image of Volgograd to increase the tourist potential are given. It is established that the planning and architectural and spatial solutions of the Volgograd embankment are pedestrian-transport - two-tiered: the upper and lower tiers have different functional purposes.

The organization of the technological process of manufacturing concrete products with the use of electrothermal treatment with high-frequency currents at both large and small industrial enterprises is considered. This technology is also useful for winter concreting and field concrete work. The technology is based on the use of a centralized high-frequency power supply, made using high-power transistor voltage converters, for simultaneous processing of several products. A pilot plant for the implementation of such a technology and the results of an experiment with its use are presented. The plant capacity was estimated based on the developed work schedule. Using the example of manufacturing foundation blocks of the FBS 12.4.6 type, it is shown that the actual schedule of work on the manufacture of products using electrothermal treatment with high-frequency currents leads to the fact that the power consumed from the supply network has a relatively small value (13.2 kW), which almost any enterprise can afford.