As a result of the analysis of normative documentation and soil fixing works, a brief historical review of the physicochemical methods of soil fixing was presented. Examples of the application of these methods in Russia and the world are considered.

Keywords: subsidence soils, cementation, soaking, heaps, mudding, subsidence, deformation, pit, soil consolidation

Based on the use of additional boundary conditions (characteristics) and the integral method of heat balance, a numerical and analytical solution of the heat conduction problem for an infinitely extended plate is obtained under symmetric boundary conditions of the third kind with constant internal heat sources in time. Considering the heat flux on the plate surface as a new sought function, a simple analytical form of the specified problem is obtained. Using the proposed approach is possible for solving partial differential equations that do not allow separation of variables.

Keywords: analytical solution, internal heat sources, non-stationary thermal conductivity, boundary value problem, boundary conditions of the third kind, additional function, integral of heat balance

The functional-object visual programming environment “Algozit” is described. This environment includes a program for setting initial data on a model, a program for calculating strain and heat release, a program for displaying results. The possibility of using the "Algozit" environment in computational experiments is shown. The presentation of the algorithm for solving the problem of deforming layered samples upon impact in the form of a functional diagram is considered. The results of a physical experiment with an initial speed of a striking element of 300 m / s and 500 m / s are given. The nature of the temperature field distribution on the surface is described. The deformed forms of the woven sample are shown. Their comparison is shown.

Keywords: visual programming, programming environment “Algozit”, multi-layered woven barrier, numerical scheme, algorithm, high-speed breaking through

Within approaching the plane-stress state the problem of a high-speed rotating disk being under side pressure is considered. Within the model of a perfect rigid-plastic body and the Mises yield criterion the values of external parameters for which the plastic zones appear have been defined. The stresses in plastic zones are obtained from the solution of the Cauchy problem, which includes two differential equations to define the stress tensor nonzero component. In order to estimate the stress state in the elastic zone the equivalent stress is introduced. The maximum allowable values of external parameters are obtained from the solution of the problem when the disk is in the limit state. The numerical results are represented as the stress vector hodograph.

Keywords: the plane-stress state, Mises yield criterion, the equivalent stress, an elasto-plastic solid, a rotating disk, a stress vector hodograph

The simulation of a multilayer structure in the finite element Ansys complex is considered. The design consists of 10 layers, each of which has certain specific properties. The model is an imitation of the soil base pavement. We consider the simulation in the form of a simplified, flat statement of the problem. The analysis of the oscillations under impact. The wave field of displacements at a given part of the structure is analyzed. Based on a numerical experiment, an approach to estimating the characteristics of a layer is constructed.

Keywords: multi-layer construction, vibration diagnostics, simulation, FEM, Ansys, pulse action, dynamics, fluctuations

Of the existing methods of treating industrial wastewater (mechanical, chemical, physico-chemical and biological), it is the biological method that is of interest today, due to the fact that it is based on the ability of microorganisms and higher aquatic plants to use a variety of pollutants as a power source in the process of life, which ultimately leads to the purification of contaminated water. In the practice of wastewater treatment by the biological method, a floating plant — eichornia (water hyacinth) —was best established on the surface of the roots of which selective microbiocenoses are formed, which contribute to active biodegradation and absorption of both organic and mineral substances. The paper shows the possibility of echornia absorption of pollutants in an indoor environment and proved the possibility of purifying contaminated water with aqueous hyacinth in an indoor environment.

Keywords: water hyacinth, eichornia, pollutants, wastewater, higher aquatic plants

This article may be of interest to researchers who are designing new machine systems for felling-area works with autonomous energy supply. A methodology based on the decomposition method for creating an simulation functional model of a system consisting of a mobile wood chipper for felling-area works and a mobile energy module is proposed. The machine system of interest is an original technical solution. It consists of an autonomous energy supply module with powered by wood fuel external combustion engine and a logging machine for the production of wood chips. The functioning equipment units of the system is simulated using the MATLAB Simulink dynamic simulation environment. For the convenience of experiments, the use of LabVIEW virtual instruments is proposed for setting input and control parameters, as well as displaying output parameters. The input, control, disturbing and output parameters of each functional block of the system are described: gas generator, external combustion engine, electric generator, uninterruptible power supply, electric motor, propulsion device, wood chipper unit, hydraulic manipulator. It is supposed to use this simulation model to justify the main parameters of the autonomous system for the production of wood chips, as well as the further development of an automated control system.

Keywords: fuel chips, wood fuel, unmerchantable tree, simulation model, LabVIEW, Simulink, mobile chipper, autonomous power supply, logging

This article describes the method of dust emission suppression at a construction site. The results of the effectiveness of the developed equipment, fog formation gun, were obtained in the course of full-scale measurements in the course of stone installation works at the construction site in Rostov-on-don. The assessment of the air dustiness of the builder workplace and the degree of impact of the fog formation gun were attended with the statistical dependence of the number of dust particles PM2.5-PM10 . During the analysis, the following factors were studied: the location of the workplace at the construction site, the relative humidity and temperature. During the study, the following conditions were met: the premises were closed; the study was carried out in the process of performing stone installation works. The results of the experiment showed the effectiveness of the fog gun.

Keywords: environmental safety, fine dust, dust settling, dust suppression, ecology in construction, dust collectors, construction work, air protection, labor protection in construction, dust pollution

This article discusses the methodology for calculating buildings and structures for the maximum design earthquake using the Dynamics module + LIRA-SAPR 2019 software package, using accelerograms, collects and converts static loads into dynamic ones, and also calculates an industrial building for the situation of maximum design earthquake with subsequent analysis

Keywords: maximum calculated earthquake, calculation, seismic impact, loads, accelerogram

The article considers the methods of calculation of electric networks when choosing the locations of compensating devices of consumers. The basic network and calculation module of a complex network transformed into a full polygon is analyzed

Keywords: reactive power compensation, optimization, power line, consumer compensating devices, analytical model, reactive load, power system

For a numerical study of the stress-strain state of the edge sections of a coal vein under the influence of a mining zone, there is a mathematical model of the geomass deformation processes, which is reproduced in the form of boundary value problems of the theory of elasticity. The problem was solved by the finite element method in a variational formulation, in which the functional was minimized with full potential energy to determine displacements in narrow of elements. Computational experiments were carried out using the author's complex of programs. Based on the results of numerical modeling, recommendations for strengthening the coal target and definitely bearing capacity was developed. The use of the developed mathematical model and software package allows us to design documents at the development stage, to predict the stress-strain state of the geomass in the zone of influence of the underground mining system.

Keywords: Mathematical model, numerical modeling, computational experiment, software package

The article provides information on the use of the geoinformation database of commercial real estate in the city of Rostov-on-Don. The database is designed to store information about commercial real estate with the aim of effectively managing the technical condition of the facilities. The prerequisites for creating a geographic information database was the need to manage the technical condition of commercial real estate of large companies on the basis of an outsourced agreement. The reference-geographic information system of commercial objects can be used for effective management, data processing and optimization of applications.

Keywords: geographic information systems; commercial real estate; technical exploitation; energy efficiency

This article is the result of a study of project documentation, one of the largest oil companies in the Russian Federation. This article aims to identify and identify systematic errors and deficiencies in the design of oil fields, which can lead to significant risks of accidents, damage to equipment, violation of the integrity of buildings, the emergence of threats to human life. The aim of the author was to identify and systematize these shortcomings, to offer the best options for correction for the purpose of further application, qualitative improvement and acceleration of the design of oil fields. Further examples of errors and shortcomings of project documentation, expected consequences which can occur if not to eliminate these errors and all necessary normative base on these questions will be given. Errors at the design stage, in turn, can lead to disastrous consequences, ranging from increased construction time, ending with emergencies and irreparable damage to the environment and human health, which leads to enormous economic losses. Design errors, even the most insignificant, can be compared with the butterfly effect. A minor mistake in the project can lead to grandiose consequences. Ballasting of pipelines. Ballasting of pipelines is taken into account in the installation of pipelines through water obstacles or water-bearing sections, when laying in the swamp.Depth of laying of pipelines at crossing of water barriers. The development of design solutions in the field of transitions on the materials of surveys that were carried out more than two years ago, without the implementation of actual engineering surveys is not allowed.Electrochemical protection of pipelines. At all available ways of laying, (except above-ground), irrespective of degree of aggressiveness of soil, pipelines shall be protected by complex anticorrosive substances and means of electrochemical protection are applied.The location of the purge of candles on the pipelines. The distance from a certain point to the purge plug in the construction of main pipelines from overhead wires must be taken from 300 meters, under cramped conditions of the route of high-voltage overhead lines, this distance can be reduced to 150 meters.the aim of the study was to identify design errors and their consequences, with the aim of further prevention and accounting. The result of these adjustments and corrections will be both cost savings and reduced construction time

Keywords: design, defects, field, capital construction, operation, analysis, research, documentation, expertise, violation

In this paper, the previously obtained equation of motion in displacements is used to determine the frequencies and forms of free oscillations of the underground gas pipeline. The problem of solving this equation is reduced to finding the eigenvalues of the determinant, which are the squares of the natural frequencies of the cylindrical shell. Neglecting the secondary coefficients of the determinant and equating them to zero, the formula for the square of natural frequencies of an underground rectilinear thin-walled gas pipeline exposed to the action of internal working pressure and longitudinal force is obtained, taking into account the reaction of elastic resistance of the soil. Substituting the values for the wave numbers in the longitudinal and circumferential directions into the obtained formula, expressions for determining the frequencies according to the rod and shell theory are derived.Using these expressions, the dependence of the frequencies of free oscillations of the depth of the pipeline at fixed values of the pipe wall thickness, the coefficient of elastic resistance of the soil and the length parameter of the plot, for different values of internal pressure, the ratio of longitudinal compressive forces. When analyzing the results, it was found that with increasing depth of the pipeline, the frequency of free oscillations decreases, and at a certain depth, the frequency of free oscillations becomes equal to zero, this indicates a flattening of the cross section of the pipeline. Using the dynamic stability criterion, for which the frequency of free oscillations turns to zero, an expression is obtained that allows to determine the depth of the pipeline at which the stability loss of the second kind occurs.

Keywords: pipeline, frequency of free oscillations, depth of laying, coefficient of elastic resistance of soil, loss of stability

Within the plane-stress state the problem of a high-speed rotating disk being under side pressure is considered. Within the model of a perfect rigid-plastic body and the Mises yield criterion the allowable boundaries of external parameters have been defined. Within the model of a perfect elasto-plastic solid and the Mises yield criterion the limit state of the disk has been considered. The displacements and the deformations are assumed to be negligible quantity; deformation plasticity theory is chosen. The problem of defining the stresses is ecstatically determined. The displacements are determined together with the stresses. In order to define the displacements as single-valued within the model of a perfect elasto-plastic solid when the disk is in the limit state it is chosen the condition that the plastic deformations inside the disk side surface are equal to zero. For the model of a perfect rigid-plastic body in order to define the displacements as single-valued the displacements values inside the side surface of the disk are needed to be determined. Plots of numerical calculations for the stresses, the deformations, the displacements and the stress vector hodograph have been introduced.

Keywords: the plane-stress state, Mises yield criterion, the limit state, a rigid-plastic body, an elasto-plastic solid, a rotating disk, a stress vector hodograph