Studies of mechanical properties of ethylene-tetrafluoroethylene (ETFE) film they are relevant for wide application in the construction of translucent coatings in the climatic conditions of Russia, especially in the Arctic zone. Power tests were performed for a film with a thickness of 250 microns on an INSTRON bursting machine, as well as with a uniformly distributed load at positive and negative temperatures. The initial modulus of elasticity according to GOST 34370-2017 was established, which was 1090 MPa. Three loading stages have been identified for the calculations of translucent coatings. In the elastic stage of operation of the ETFE film, the average modulus of elasticity was 35.8 MPa, in the elastic-plastic stage - 1.78...2.71 MPa and in the plastic stage of operation - 0.06...0.086 MPa. Force tests of a membrane made of ETFE film with a thickness of 250 microns on a power triangular frame with a uniformly distributed load of up to 8,577 kPa did not lead to rupture of the membrane at any positive (+15 ...+18 ^о С) not at subzero temperatures (-23...-29 ^о С). Repeated mechanical damage (cuts) of the membrane under a load of 8.50 kPa at a temperature of -26 ^о С also did not lead to its rupture. The deflections of the membrane at positive temperatures reached 84 mm, at negative temperatures - 58.2 mm. Power tests of the ETFE film have shown its ultra-high strength characteristics, which makes it possible to widely use it to create a comfortable environment in structures erected in the Arctic and other territories of Russia when localizing production in Russia.

The article substantiates that in cylindrical vaults with stripping and cross vaults of historical buildings, the most stressed areas are the areas where the vaults rest on the supporting structures (walls and pillars) and the zones of interface between strippings and vaults. In particular, in cross vaults, the most loaded are the diagonal ribs, in which the compressive forces act at an angle of 45° (it is in this direction that the masonry has the least resistance to compression), and the flow of compressive forces within the diagonals of the vault accumulates, reaching maximum values in its supporting heels. From which it is concluded that it is the supporting consoles that most often determine the bearing capacity of the cross vault as a whole. The article gives approximate calculated dependences for assessing the bearing capacity of the supporting consoles of the cross vaults and concludes that the most accurate picture of the stress state of the supporting consoles can be established by numerical modeling, and to assess the bearing capacity, it is necessary to use particular strength criteria.

The article is devoted to the numerical analysis of the stress-strain state of fiber reinforced concrete slab structures under emergency dynamic impacts. A prefabricated cover slab of a protective structure buried in the ground is considered. Shock effects on the slab are considered to be blast ones. An explosion at the ground surface or another impulse transmitted through the ground to the structure is assumed to be the cause of their occurrence. The change in time of the components of the stress-strain in concrete and reinforcement is investigated in case of change in the suppleness of the supports. The possibility of rigid or elastoplastic deformation of supports under impact action is considered. By means of a concrete example, the efficiency of the suggested approach is demonstrated under symmetric loading by a blast load taking into account a variable shock spot area. Numerical modeling has shown that under both static and dynamic additional loading the slab fractures along the fibro concrete with the formation of a cable mechanism while preserving the survivability property of the reinforcement. It is shown that the use of compliant supports plays an essential role in damping of vibrations and allows to regulate both the level of mechanical safety of the structure and its material capacity. The necessity and urgency of determining the actual damping properties of the structures of the considered type has been established.

A review of scientific research related to the limitation of the right to life of reinforced concrete structural systems, taking into account incompatible and non-linear processes. Particular attention in the scientific review is devoted to the analysis of the work necessary to study the use of concrete and reinforced concrete building structures of buildings and structures. The fundamental phenomenological theory of creep is systematized and given from the classification. The significance of the proposed scientific review lies in the fact that there is a high value and transience of phenomenological theories of concrete creep, primarily for the calculation of reinforced concrete structural systems, taking into account non-equilibrium heavy and nonlinear processes.

The article presents a technique for carrying out experimental and numerical studies of reinforced concrete frame-fragments of a prefabricated monolithic reinforced concrete structural system of multi-storey buildings. The purpose of the research was to determine the nature of the change in the parameters of static-dynamic deformation and force resistance of the proposed structural system both at the stage of operation and during an emergency impact caused by the shutdown of one of the elements - the corner column of the first floor. To increase the resistance of the system under study to local or progressive collapse, new design solutions for the crossbars of the prefabricated monolithic frame are proposed, which make it possible to increase its resistance to a sudden change in power flows in the structural system under consideration. Analytical dependencies are proposed to determine the parameters of the intermedium contact zone in the prefabricated-monolithic structure of the crossbar. The solution of the problems under consideration was carried out using the LIRA-SAPR software package, taking into account material operation diagrams that take into account the static-dynamic nature of the loading of structures. The substantiation of the adopted design solutions for experimental designs of frame fragments for developing a program for conducting experimental studies of the structural system under consideration under special effects is given.

The necessity of developing solutions that increase the resistance of load-bearing systems to progressive destruction, leading to instant or prolonged destruction of individual structural elements and assemblies, is considered. The plug joint columns in prefabricated and prefabricated monolithic frames designed for compressive forces, in case of emergency impact, begins to work on tension. The maximum tensile forces in the columns and joints of a typical prefabricated frame in case of emergency impact are determined and options for upgrading the design solutions of the plug joint are proposed. It is proposed to use a plug-in part for the well of the plug joint of the prefabricated columns, which provides work for tensile forces. Multivariate numerical simulation of the plug joint was carried out taking into account the tensile work, strength characteristics were determined. Recommendations have been developed for the design of a plug joint for load-bearing systems, taking into account their work with progressive destruction, recommendations for reinforcing the joint depending on the efforts in it have been proposed. The results can be used in the design of plug joints of prefabricated and prefabricated monolithic frames.

Modern design standards of developed countries have significant differences in the design provisions for determining the bearing capacity of monolithic reinforced concrete slabs for punching and do not fully take into account the features of design solutions and operating conditions. The available design positions are designed for the static loading mode of structures. The stress-strain state of plates for punching under dynamic load is currently little studied, and as a result, there are no methods for determining the bearing capacity of plates for punching under dynamic loading. The article presents the results of experimental and theoretical studies of the bearing capacity of plates under static and dynamic loads. The methodology of experimental studies and the design of prototypes, equipment for conducting power tests are described, the results of studies on the penetration of fragments of the interface of flat reinforced concrete monolithic slabs with a column under dynamic and static loading are presented. A comparison of the destructive load for samples tested under dynamic loading with the destructive load for samples tested under static load is presented. The factors affecting the strength of the plates during punching under dynamic loading are determined. Proposals have been developed to improve the methodology for calculating the strength of flat reinforced concrete slabs when pushing through static and dynamic loads.

The article is devoted to the actualization of issues related to the problem of preserving objects of cultural heritage of federal significance located on the territory of the Altai Territory. The brief analysis of the monuments allows us to bring together and present the key problems associated with the physical state of objects and changes in their historical appearance, which affect the cultural and historical landscape of the city and the perception of monuments. The results of the collected material and the analysis of monuments introduced into scientific circulation will expand the understanding of the stages of development and the current preservation of cultural heritage sites in the region. The Altai Territory is valuable not only for its natural and climatic conditions, but also for the history of the development of the region, which is directly connected with the cultural center of the Russian Empire, St. Petersburg. Unique cultural objects are a direct confirmation of the connection of a remote province with the capital, their small number and rapidly deteriorating cultural landscape actualizes the issues of preservation of objects in the historical and urban environment, and in the future will allow you to come as close as possible to solving the issues of comfortable urban development, while maintaining their authenticity.

The modern urban environment, as an urbanized area, is a high-tech environment where citizens lead an active lifestyle and economic activity. As a result of the growth of the urban population, there is a need to develop the urban territory: urban spatial objects are being improved, the number of residential and public buildings is growing, transport networks and engineering infrastructure are developing. As a result, the density of urban development increases and the intensity of traffic flows increases. Such rapid changes in urban space seriously affect the ecology of the environment. In addition, anthropogenic factors resulting from the active economic activity of citizens create an additional burden on the ecology of the urban environment. In this regard, the issue of the formation of ecology in modern cities is becoming increasingly important. The presented article is devoted to the analysis of factors affecting the ecological state of modern megacities. Causes of violation of aeration of the urban environment, revealed in the process of research, can be taken into account in urban planning. The regulation of air flows of thermal origin, arising in the yard spaces, promotes air circulation in closed yard spaces, which will improve the ecological state of the air environment.

This work is devoted to the issues of integrated development of rural areas. The advantages of a systematic approach to the main policies of the sustainable development paradigm goals implementation and the possibility of using geoinformation technologies as a tool for multidimensional analysis of rural areas are considered. The assessment of the landscape ecological potential is complicated due to the variety of criteria for analyzing the territory and the lack of a common unit of measurement. The methodology of a comprehensive assessment of the territory allows integrating diverse information about the of rural settlements territories ecological potential. Special attention is paid to the state of ecology as one of the most important criteria for environmental quality. A two-stage methodology for monitoring the development of rural settlements is proposed, which allows assessing the territory at the federal and local levels according to a set of indicators reflecting the main aspects of socio-economic processes. For places where the population lives compactly, special attention is paid to assessing the quality of the environment according to three groups of factors that take into account environmental comfort, comfort of movement and other indicators that characterize the quality of the environment in terms of the individual needs of residents. The experimental part of the article presents electronic maps built in the ESRI ArcGIS and based on first-level evaluation factors for the Rostov region.

Composites of different composition and structure have been obtained on the basis of crushed porous stems of Sosnovsky's hogweed modified with borazote for biostability with the use of organopolymer binders. The particle size of the plant material varied from 1 to 10 mm. Polyvinyl acetate, polyurethane, and casein were used as binders. The ratio of the components (vegetable raw material: polymer) in the composites was 3:1 by mass. Biostability and thermophysical properties of the composites obtained were investigated by applying appropriate GOST methods. It was established that the preliminary modification of vegetable raw material particles with monoethanolamine (NB)-trihydroxyborate provides 100% biostability of composite materials based on used raw materials and organopolymer binders. The use of the above modifier is equally effective for all composites obtained using different types of binders: polyurethane, polyvinyl acetate, and casein. The composites obtained on the basis of modified plant raw materials and organopolymer binders are heat-insulating materials characterized by appropriate coefficients of thermal conductivity and density. Composites based on polyurethane binders have lower thermal conductivity compared to composites based on polyvinyl acetate and casein binders and belong to class A. The polyurethane binder provides the resulting composites with a particle size of 5 mm with an increased compressive strength as compared to the composites based on polyvinyl acetate and casein binders. Thus, the optimal composition of biostable heat insulating material is the composition based on modified plant raw materials with a particle size of 5 mm and polyurethane binder.