An engineering method for calculating shock noise isolation by floor-to-floor overlappings with wood-based materials is proposed. The calculation considers overlaps with floors made of wood materials laid on glue and with floors laid on an elastic substrate. The calculation takes into account the effect on sound insulation of the surface density and stiffness of the floor covering material and the sound insulation layer. The calculation is reduced to calculating the frequency characteristic of reducing the impact noise level due to the construction of a floor made of wood materials and comparing the calculated value of the index of the reduced impact noise level with the standard ones. The list of necessary input data and the sequence of calculation execution is given. Approximate formulas for calculating the frequencies that limit the application of computational models of the overlaps under consideration are compiled. Equations and approximate formulas are given for determining the critical (antiresonance) and resonant frequencies of vibrations, one -, two-and three-layer overlaps, and their values are determined for various mechanical and geometric parameters of layers. Frequency ranges of growth and decrease of shock noise level by these overlaps are determined. Comparison of the calculated and measured frequency characteristics of shock noise reduction showed a good correspondence of the results obtained by the engineering method of calculation with experimental studies. The developed practical recommendations for improving the isolation of shock noise between floors with floors made of wood materials, used in the construction of civil buildings, can increase acoustic comfort in buildings under construction and under reconstruction.

A computational model of the complex resistance of reinforced concrete structures in buildings and structures under torsion with bending is proposed, consisting of a support block (formed by a spatial crack and a compressed concrete zone closed on it, - spatial section k) and a second block formed by a vertical section I- I, passing perpendicular to the longitudinal axis of the reinforced concrete element along the edge of the compressed zone, closing the spatial spiral-shaped crack. Cases are considered when the torque effect has the greatest influence on the stress-strain state of structures. We have a design diagram A of the resistance of a reinforced concrete structure under the combined action of a bending moment, torque and shear force for a spiral-shaped spatial crack, as well as a design diagram B for a spatial X-shaped crack. In this case, as the design forces in the spatial section, the following are taken into account: normal and tangential forces in the concrete of the compressed zone; components of axial and thrust forces in the working reinforcement crossed by a spatial crack. Resolving equations are constructed that form a closed-loop system and the Lagrange function that unites them is written. Using the partial derivatives of the constructed function with respect to all the variables included in it and equating them to zero, an additional system of equations is compiled, from which, after the appropriate algebraic transformations, a dependence is obtained that allows one to find the projection of a dangerous spatial crack.

The article discussesthe research of the traditional circular archs of timber jambs, designedin the 16-th century by the French architectPhilibert Delorme, with an option of its strengthening, which make this arch comparable to the glued timber one. The experimental research of a flat arch, made of small wooden bricks strung on a steel rope and prestressed from the foundationzone, was carried out in the NRU MGSU. According to the results, it was found, that the arch has a low carrying capacity and can work only on compression. However, by strengthening the arch by using a steel band along its upper face and thus moving to the truss structure, it is possible to increase significantly its carrying capacity and bring it closer to the glued timber arch. During tests, it was noted that by the character of its work this arch is close to the circular arch of timber jambs. In the LIRA-CAD PC a computer simulationwas carried out of the traditional and the strengthened by a steel band along its upper face circular arches of timber jambs, as well as the glued timber arch. The following results were obtained.During the deformation process, the deflection of the strengthened circular arch decreased by 31%, and the stresses in it decreased by 26% compared to the traditional one, and according to the carrying capacity the arch has become comparable to the glued timber one. On this basis the conclusions were obtained, that it is possible to create non-linear form constructions, inherent to the natural objects, using the strengthened circular arch.

A computational model and the results of numerical studies of the structure of a platform joint in a reinforced concrete precast-monolithic frame of a building from panel-frame elements of industrial production are presented. Modeling of the plane stress state of the joint structure is carried out by a finite element scheme, using finite elements of different types and a nonlinear law of deformation to determine the design characteristics of reinforced concrete. The parameters of deformation of the platform joint structure at different loading levels, including stage-by-stage cracking and destruction, have been determined. The schemes of distribution and stress concentration zones in the characteristic sections of the platform joint are established when the distributed load is transferred from the frame of the panel-frame to the hollow-core floor panels and concrete for embedding the joint in the presence of a cavity in the frame frame for centering elements.

Innovative spatial forms appear and develop at the joint of science, art, and architecture. Geometry is the most important, fundamental components of architectural forming. Now, having passed the stages of passion for the large-span shells, the sky-scrapers, typical inexpensive buildings, architectural bionics and ergonomics; pneumatic, membrane, wire rope and shrouds erections, the architects and designers payed attention at analytically non-given forms of erections and at the polyhedron. It is noticeably especially at the last 10-15 years. In a paper, the problems of application of the polyhedron and their modifications in architecture, building, and technics are analyzed. They consider prisms, pyramids, prismatoids, Platonic and several Archimedean solids, quasi-polyhedrons, and some figures constituted on their base. Polyhedral domes, umbrella shells, and hipped plate constructions are presented too. Large quantity of the illustrations devoted to the architecture of buildings and erections, to the landscape architecture and to the sculptural compositions is presented for the confirmation of increasing interest to these structures. 31 titles of the used original sources are given.

The article describes the approach to evaluation of a friction pile bearing capacity based on the parabolic distribution of a skin friction in multi-layer soil bases. The design equationsare obtained for evaluated the ultimate load on an axial loaded pile in multi-layer soil using the new design scheme. The advantage of the proposed approach is to obtain some experimental parameters that take into account the actual interaction of the pile and soil on the construction site. Negative friction forces (from the reaction force under the pile end) negatively affect the pile bearing capacity. The numerical example is given for a friction pile in the soil base with two layers. The proposed equation also allows calculating various parameters: the soil stress under the piletoe, the pile effective length, relative deformations along the pile, etc.

The article presents the results of numerical simulation of the dynamic response of a reinforced concrete frame of a multi-story building with the sudden removal of load-bearing columns using a detailed 3D model in the LS-DYNA program, whichimplements the explicit finite element method. The model takes into account the nonlinear behavior of the material. The influence of the deformation rate of concrete and steel reinforcement is taken into account using the coefficient of increasing the strength of materials, normalized in SP 385.1325800.2018. The numerical results of the study showed that using the proposed calculatedmodel, it is possible in each moment to track the stress-strain state of load-bearing elements of frame-rod system frame high-rise buildings, to check criteria special limit state designs, andto answer the important practical question of the sustainability of a building to progressive collapse under a givenbeyond design action and as a result take in the design of necessary protection measures.

The research 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 field survey of preserved fragments of the settlement of Korennaya Pustyn. Scientific novelty of the research is to carry out the author's expeditions and surveys of the building complex of the town Korennaya Pustyn (the monastery fair, village) (measurement, photographs, sketches from nature), identify archival and printed sources, resurrecting the images of the lost nobility and merchant estates cottages, carried out a General analysis of the given topic, as well as appear obscure architects D. Kvarengi, V. A. Serbina, N. And. Kozlowski, L. M. Grigoriev, etc.. An important result of the research is the disclosure of the phenomenon of suburban estate construction in Kursk province as a dacha settlement in the monastic and fair complex of the town of Korennaya Pustyn in the 2nd half of the XVIII - 1st half of the XIX centuries.the architecture, spatial composition and structure of the entire complex of a unique settlement are considered. A comprehensive study of architectural and planning features of estate complexes in Kursk province reveals special regional features of estate construction. The paper highlights traditional and reveals new structural and planning characteristics in the structure of estate complexes in the southern region of the Russian border region.

This paper considers the use of highly permeable concrete, al-so known as drainage, porous, coarse-grained, moisture-permeable, permeable concrete, in road construction, which is a special type of concrete whose porosity is higher than most others. High permeability of water through the body of the concrete structure to the lower layers of the base is achieved due to interconnected pores and voids. Highly permeable concrete pavement is used to reduce local floods in ur-ban areas, acting as a sustainable drainage system. The permeability of permeable con-crete can be reduced during operation due to clogging of pores, this leads to a limitation of the service life of such a coating. The issues of studying the mechanism of clogging and ways to combat it remain open.

The paper presents research on the development of building materials with low CO ₂ emissions based on industrial man-made materials. The optimal recipe-technological parameters for the production of materials based on lime dust generated by mechanical deposition in cyclones and bag filters of shaft furnaces, as well as finely divided marble-like limestone with a fraction of up to 5 mm were determined. Studies have shown that it is possible to obtain a building material with compressive strength of more than 40 MPa from this recycled material by forced carbonization for three hours. Moreover, to obtain such strength indicators, the optimal content of lime dust in the raw materials is in the range of 35-40% wt. when the water content of the mixture is 6-7% wt. The carbonized material obtained at the indicated technological parameters will have an average density of 1.95-2.0 g / cm ³ and water absorption by weight of not more than 12%. Accordingly, the data obtained make it possible to judge the possibility of obtaining high-quality construction products with physico-mechanical, physico-chemical, hydrophysical, and other properties sufficient for building materials.

Generalization and analysis of scientific hypotheses and theories of domestic and foreign researchers in the field of the frost action mechanism on concrete has been performed. A critical author's assessment of them from the point of view of the basics of physical chemistry of silicates and solid state physics is presented. The initial prerequisites for the frost resistance of heavy concrete and equal-strength structural light concrete in connection with their structure are formulated, including of this article author's targeted experimental studies on the relationship of the frost resistance of these concretes with their pore structure. Thermodynamic models of freezing-thawing of water, including its adsorption layers in capillaries of cement materials porous structures are used. The data of studies of the critical degree of water saturation of concrete are considered and a reasonable assessment of it is given as an integral characteristic that determines the possibility of formation of micro- and then macro-defects in the concrete structure during its cyclic freezing and thawing. Based on the results of analytical and experimental studies, using the basic principles of physics of the solid state, as well as the physical and physical-chemistry of silicates, has been developed the physical-chemical basis for the resistance of structural lightweight concrete in comparison with equally strong normal weight concrete to the effects of low (up to minus 70 °C) subzero temperatures. The results of this work are considered by the authors as a modern scientific basis for the development of the main provisions of the technology for manufacturing structural lightweight and normal weight concretes with high durability (frost resistance and water resistance), intended for reinforced concrete structures of engineering constructions, operated in severe climatic conditions, including in the conditions of the Arctic coast.