The article provides a brief overview of geomechanical methods for studying the stress-strain state of the soil mass and tunnel lining. The organization of monitoring in tunnels using conventional and fiber-optic systems is considered. Criteria for analysis of monitoring data and structural strength conditions are described

Keywords: railway tunnel, construction, operation, monitoring, strain gauge, stress, strain, strength, bearing capacity

The results of the development of a polymer protective coating based on oligopiperylene styrene binder for the protection of concrete and metal surfaces of structures of buildings and structures from the effects of adverse natural and technogenic factors are presented. Modification of this binder with tetraethoxysilane in an amount of 3-20 wt. including allows you to get a protective coating with good hydrophobic properties. Introduction to the composition of 1-12 wt. including tetraisopropyl titanate significantly improves the adhesive and strength properties of the protective coating, which is associated with the formation of bonds between oligopiperylene styrene and tetraisopropyl titanate, due to chemical interaction between the reactive groups of these compounds. The developed protective polymer coating provides good adhesion to the working surface, is easy to apply technologically, the curing of the coating occurs at room temperature, and the improvement of the strength and hydrophobic characteristics of the coating will significantly expand its field of application.

Keywords: protective coating, oligopiperylene styrene binder, tetraethoxysilane, tetraisopropyl titanate, adhesion, hydrophobicity, contact angle

This article is devoted to the study of a medieval temple Dating from the end of the X - beginning of the XI century, located near the village of datuna in the Republic of Dagestan. It discusses its design features, provides arguments about their possible purpose and symbolic load. Stylistic and semantic analysis is carried out, as a result of which conclusions are drawn about the ownership of construction traditions. The proportions of the temple underlying the compositional structure are analyzed. Based on the revealed proportions, an analogy is drawn with the temple of Solomon, with which other common features are found. As a result, it is concluded that it served as a prototype for the construction of the Dagestan temple.

Keywords: Datun temple, middle ages, religious architecture, Dagestan, proportions, single-nave Basilica, compositional structure, prototype

The article is devoted to the use of natural minerals in water treatment. The paper presents the results of a study of the sorption properties of the opoka. The study showed the advantages of flask membranes compared to those deposited with silicic acid. The optimal conditions for the modification of the flask were determined, which make it possible to purify water from metal impurities to the required level.

Keywords: groundwater, water purification, deferrization, membrane, deposited membrane, sorption methods, flask, polyacrylamide

A hydroacoustic waveguide is considered as a linear system with parameters distributed over dis-tance. A method is proposed for modeling the impulse response of a waveguide. The fields of indi-vidual normal modes at fixed frequencies are calculated so that discretization theorems are satisfied. By performing the inverse Fourier transform of the fields of all modes separately, the time realiza-tions are restored. Then, summing the mode fields, the impulse response of the waveguide is calcu-lated. This approach allows you to "turn off" the fields of individual modes, add, if necessary, the fields of higher modes, or to study all fields separately, simulating the operation of mode selection. The impulse response is considered as a tool for solving the problems of inverting the acoustic characteristics of the seabed and modeling the propagation of signals in waveguides. The impulse response of the first mode of the Pekeris waveguide with the bottom in the form of an intermediate layer and half-space is restored, its wave attributes are revealed: ground wave, water wave, Airy wave. The frequency dependences of the group velocity of normal modes and the multimode im-pulse response are restored. Low-pass filtering of the impulse response makes it possible to reveal the Airy phase of the first mode.

Keywords: normal modes, seabed, attenuation coefficient, group velocity, impulse response, intramode dispersion, intermode dispersion

The paper explores the opportunity to use tower cranes with a large boom length for installation of space frames configured as prefabricated units. The opportunity to modify the already existing technology by using new tower cranes with a large boom length allows cutting the cost of construction of industrial buildings with flat structural plates. Cost cuts are realized by reducing the scope of works pertaining to installation and dismantling of crane runway as well as crane relocation toward other spans of the building.

Keywords: space frames, nodal connections, installation, technology, modification, crane

A survey of the frame-panel building was carried out, in which ecowool was used as the heat-insulating material. A study was made of the moisture state of wooden frame walls and attic floors. Ecowool samples were taken from various sections of the wall. No mold was detected on material samples. In this case, the sorption humidity was not more than 16%. The results of laboratory tests of ecowool showed high persistence of density and coefficient of thermal conductivity during long-term operation. Tests were conducted to determine the effect of moisture on the change in the physical and technical properties of ecowool. The research results were processed by statistical methods. As a result of the study, it was found that moisture does not accumulate in the ecowool layer of the examined frame walls and attic flooring, but goes out through the insulation and elements of the building envelope. The conducted studies allow us to predict the preservation of the heat-shielding properties of ecowool during operation for a long time

Keywords: ecowool, durability, sorption humidity, density, coefficient of thermal conductivity

The granulation process of ammophos in a drum granulator-dryer (DGD) is considered. The main factors affecting the granulation process are considered. The inputs and outputs of the mathematical model of the granulation process are determined. A dynamic mathematical model has been developed for the formation of the equivalent diameter of ammophos granules depending on the flow rate and particle size distribution of the external recycle. Graphs of comparison of simulation results with actual data of normal operation are presented. A graph of the dependence of the equivalent diameter of the granules on the flow rate of external recycling is presented. The model is intended to create a system for stabilizing the granulation mode.

Keywords: ammophos, recycle, granulation, particle size distribution, drum granulator-dryer, modelling, mathematical model

In the view of most people, the criterion "high-rise buildings" is very blurred. Five or seven storey buildings were considered one or two centuries ago to be tall, but now you will not surprise anyone with a number of storeys over fifty. Russian law sets the maximum possible 75-meter height for residential buildings and 50-meter - for public buildings. The construction of higher facilities is subject to special requirements. The article discusses the development of high-rise buildings of a megalopolis using the example of the city of Rostov-on-Don, presenting famous high-rise buildings in Rostov at present. Along with increasing the number of storeys of buildings, their design features are also changing. The types of structural schemes of high-rise buildings, the materials of the supporting structures of high-rise buildings, their advantages and applications are described. The problems that arise in high-rise construction are described.

Keywords: Rostov-on-Don city, high-rise construction, number of storeys, development, urban planning, zoning, architecture, design, high-strength concrete, high-strength reinforcement

This paper presents the results of the development of a heat-insulating coating based on a polymer binder for thermal insulation of hot metal surfaces of industrial equipment, process plants, pipeline surfaces, operating at temperatures up to 100 0C. The heat-insulating coating is based on a polymer composition containing a mixture of acrylic polymer and styrene-butadiene rubber, hollow phenol-formaldehyde microspheres, pigment and water as a binder. The use of phenol-formaldehyde hollow microspheres in this composition in an amount of 20.0 to 40.0 wt. % as a filler, it allows to reduce the thermal conductivity of the developed coating and increase its strength characteristics, in comparison with a similar coating containing carbon microspheres. The use of this composition allows to obtain a polymer coating with high thermal insulation and mechanical properties.

Keywords: heat-insulating coating, acrylic polymer, styrene-butadiene rubber, hollow phenol-formaldehyde microspheres, tensile strength, thermal conductivity

The article presents theoretical calculations and studies of the possibility of parametric oscillations and parametric resonance arising in a polymer self-supporting thermoplastic pipe "Furanflex". Тheoretical calculations of the possibility of asymmetric parametric oscillations and parametric resonance are considered.The Furanflex thermoplastic, polymer liner is offered as a variant of a separate gas exhaust trunk during the reconstruction of boiler rooms and thermal power plants by heat generating companies.The description and calculation of resonant phenomena for asymmetric parametric oscillations are described in detail.Detailed mathematical transformations of differential equations of parametric oscillations are given.The article provides a detailed description and analysis of the occurrence of parametric oscillations. Examples of symmetric and asymmetric parametric oscillations are considered.Information and conclusions of the presented work are intended for a different range of readers, teachers, designers, students of construction specialties.This article should be of interest to utility managers and heat generating companies .

Keywords: chimney, ventilation duct, repair, restoration of the chimney,protection of the chimney, lining, furanflex, thermoplastic liner,perimetric oscillation

the article describes a variant of setting sequential algorithms in the form of bipartite graphs by further defining them, which makes it possible to work with algorithms using graph theory methods in the future. Two forms of the task are considered: modular and functional-predicative. The possibility of setting the algorithm in table-predicate form is shown. It is concluded that in addition to the generally accepted methods of setting the algorithm, it can be set in matrix-predicate or table-predicate form, which allows using methods of matrix theory and methods of predicate theory when working with algorithms. setting the algorithm in matrix-predicate form avoids isomorphism when performing algebraic and set-theoretic operations on it.; setting algorithms in matrix-predicate form allows you to perform almost any operations on them

Keywords: graph-algorithm scheme, sequential algorithm, predicative block, functional block, pre-definition, bipartite graph, table-predicative form, graph theory, isomorphism

There is an analysis of the urban development location and the capacity of public spaces for cultural and educational purposes was carried out using the example of cultural centres for Volgograd. The normative and actual material security is determined separately for each administrative district and whole sity. There are suggestions on the advisability of erecting new cultural objects.Dynamics of modern cities is taking into account.

Keywords: planning, cultural centre, cultural and social structure, standard of material security, actual material security

The article is devoted to the study of the adequacy of the model of a waveguide with a bottom in the form of half-space in broadband calculations of sound fields. Two bottom models are considered: liquid and porous. Two depths of the water layer are considered - units of meters and tens of meters. In the case of a liquid bottom, the speed of sound and the loss tangent in the bottom are considered to be frequency independent (model with a bottom with constant quality factor). In the case of a porous bottom, the frequency dependence of the speed of sound and the loss tangent is extracted from experimental data published in open sourses. The frequency dependences of the group velocities of the modes and modal attenuation coefficients are calculated. The frequency dependences of the group velocity of the first mode for the two waveguide models coincide, and the critical frequency of the normal modes changes in proportion to the depth of the water layer. The frequency dependences of the attenuation coefficient of normal modes turn out to be significantly different. The impulse response of shallow and deep-water waveguides are simulated. It is shown that in the case of a waveguide with a water layer depth of a few meters, the temporal structure of the impulsive field is indistinguishable - the bottom model without dispersion is adequate. In the case of a water layer depth of tens of meters, the temporal structure of the pulsed field for two bottom models is different - the waveguide model with a bottom without dispersion is inadequate.

Keywords: liquid bottom, porous bottom, marine sediments, dispersion of phase velocity, group velocity, intramode dispersion, intermode dispersion

One of the most pressing problems in the oil and gas industry is numerous pipeline accidents that require innovative solutions. This article analyzes a promising method of repair using composite couplings, which include many advantages compared to steel structures. The strength characteristics of the couplings are also given and their installation process is described.

Keywords: Oil pipeline, overhaul, reinforcing composite coupling, composite materials