Stress-deformed State Research Articles

MATHEMATICAL MODELING OF THE DYNAMICS OF AN ELASTIC HALF-MEDIUM WITH A CYLINDRICAL CAVITY REINFORCED BY A SHELL UNDER AXISYMMETRIC LOADS

Purpose. The development of a mathematical model of an elastic semi-medium with a cylindrical cavity reinforced by a shell and a plate that reinforces the surface of the semi-medium based on the finite-element approach. The non-stationary dynamic stress-strain state of this mechanical system under axisymmetric surface loads, which depends on time as a unit Heaviside function was analyzed. The solution of the corresponding static problem was obtained. Based on the obtained results, the dynamic coefficient of the considered mechanical system was calculated.
 Research methods. The finite element method and the Wilson - method were used for solving static and the corresponding dynamic matrix equation correspondingly. The last one allows reducing the differential matrix equation to an iterative sequence of quasi-static problems. To obtain an approximate solution of systems of linear algebraic equations that take place in the process of solving static and a sequence of quasi-statistical problems, the conjugate gradients method was used.
 Results. A finite-element model of the mechanical system of an elastic semi-medium with a cylindrical cavity reinforced by a shell and a plate reinforces the surface of the semi-medium was developed. The non-stationary dynamic stress-deformed state of this mechanical system under action of the surface axisymmetric loads was analyzed. The solution of the corresponding static problem was obtained. Based of the results has been obtained, the dynamic coefficient of the considered mechanical system was determined.
 Scientific novelty. The developed approach allows to take into account the mutual influence of a cylindrical cavity reinforced by a shell and a plate that reinforces the surface of the semi-medium under the action of the non-stationary dynamic loads applied to the surface of the plate.
 Practical value. The developed mathematical models and obtained results can be used in the design of underground structures, in particular mine shafts.

TECHNOLOGY OF SHAPING AND ANALYSIS OF CONTACT INTERACTION OF MACHINE PARTS

Elements of transmissions and other machine parts in many cases have a complex shape of contacting surfaces. On the one hand, their form is determined by kinematic conditions associated with the transfer of motion between structural elements. On the other hand, the design geometry is limited by strength criteria. Keeping the shape of the contacting surfaces as close to each other as possible generally facilitates the reduction of stress levels. As a result, there is a combined problem of synthesis of geometric form and analysis of kinematic interaction of complex-profile bodies. A general approach that implements objective-driven variation of the shape of the contacting bodies has been developed for this purpose. At the same time, the varied geometric shape is approximated by prismatic finite elements. A topologically regular mesh of finite elements is formed. As a result, it is possible to parametrize the geometrical model of the researched objects, as well as to perform automated multivariate calculations. Accordingly, this array of information becomes the basis for establishing patterns of influence of various factors on the stress-deformed state of contacting bodies. It also makes it possible to formulate recommendations regarding the substantiation of advanced technological solutions of machine parts that transmit mechanical loads through moving contact. Therefore, both the functional properties of these structural components and limitations, for example, in terms of strength and durability, are provided. A method of geometric shape synthesis integrated with generalized parametric modeling was developed, as well as an approach to geometric synthesis of the shape of kinematically generated surfaces. This makes it possible to calculate the distribution of contact pressure and the stress-strain state of contacting complex bodies. For the formation of high-quality finite-element models, a method based on the creation of topologically regular mesh in the curvilinear coordinates of the working surfaces is proposed. The application and effectiveness of the developed methods and models are illustrated on the example of two-parameter transmissions. Correspondence of the results obtained by different methods was confirmed. Keywords: complex-profile bodies; contact interaction; stress-strained state; kinematic interaction

The stress-strain state of an incompressible prestressed half-space with a protective coating under the action of a moving load

This work is devoted to the study of the influence of the protective coating, initial stresses, mechanical characteristics of materials, movement parameters of the surface load on the stress-deformed state of the elastic base. The relevance of the research results is related to the possibility of their use in the creation of qualitatively new materials, structures and building structures. A prestressed incompressible half-space with inhomogeneity in the form of a thin surface layer is considered. The concentrated force moves along the free surface of the protective layer at a constant speed at a certain angle to the surface of the half-space. The solution of the problem was obtained using the method of integral Fourier transformations. Analytical results are given in a general form for materials with an arbitrary elastic potential, for cases of unequal and equal roots of characteristic equations, for various conditions of combination of elements of a layered medium and for any speed of movement of the load. The material with the Bartenev-Khazanovich potential was considered for numerical analysis. The calculations were carried out within the framework of the theory of finite initial deformations. The impact of the moving load, initial stresses and mechanical parameters of the elements of the layered base on the main characteristics of its stress-strain state was studied.

MATHEMATICAL EQUATIONS FOR TEMPERATURE CONTROL IN THE CONTACT SURFACES OF DRILLING AND MAINTENANCE EQUIPMENT

The maintenance of equipment and tools used in the workover of oil and gas wells depends on keeping them in working condition, reliability, strength and temperature endurance of the tool. In order to restore wells in case of an accident and bring them back into operation, it is necessary to speed up the drilling and repair work by choosing the right repair equipment and following the existing rules and regulatory documents. The cutting elements of the tools working under high pressure and loads are deformed, a tense situation is created in the cutting – destruction zone, high temperatures (10000 - 12000) occur as a result of corrosion in the triboknots. The stress-deformation state in the cutting-destruction zone causes the formation of microcracks in the working area of the tool. Microcracks grow after a certain period of time. Cutting elements are quickly worn, in some cases broken and fail quickly. Such cases affect the structural composition of the cutting elements, the temperatures increase, as a result, riveting occurs. In order to keep the equipment and tools used in the repair in normal working condition, adjusting the mode parameters is one of the important requirements, in addition to taking special care of them. The high results obtained in repair and restoration works depend on the efficiency of the cutting-destructive tool, longevity, material selection, construction manufacturing technologies, tool that meet modern requirements, dimensions, weight and internal condition of the well being restored. It is necessary to keep the heat generated in the moving parts of the tool at the required level for the safe performance of restoration works. The thermal regime of cutting and rock-destroying tools depends on the physical-mechanical properties of the objects subjected to destruction and the effect of thermomechanical stresses generated on the contact surfaces of the tool and the amount of heat released from the working surface. Studying the problems related to heat issues will allow to ensure the temperature tolerance of not only the repair equipment, but also the equipment and tools used in other areas of the oil-field industry. Keywords: temperature, cutting and destructive tool, metal, rock.

Consideration of the Influence of the Initial Stress State of Rock Bases of Hydro-engineering Structures on Models From Gypsum Porcelain Composite

Methods of researching the stress-deformed state of rock foundations of hydraulic structures are analyzed, laboriousness and costliness of large-scale natural studies in field conditions are emphasized. Rock foundations are a natural composite with an initial stress state, and its influence on the deformability of the foundations of hydraulic engineering structures is one of the most important issues of interest to the scientific world. The strength and deformation indicators of the gypsum-lime composite under compression and tension loading were determined on the samples. Based on the developed method of the stamp on a flat model made of gypsum-limestone composite, the experimental data show the influence of the experimental values of the modulus of deformation determined by the method of loading the rocks with the stamp.

Investigation of the force reactions’ magnitude around the mounts of orthodontic appliances in the process of orthodontic treatment of children with congenital unilateral cleft lip and palate

For the purpose of orthodontic treatment of children with congenital cleft lip and palate, various orthodontic constructions are used. The use of removable appliances indicated for narrowing or shortening of the dental arches, anomalies of the individual teeth position. The question of determining the magnitude of force reactions around special devices (clasps) that are designed to fix appliances on teeth during treatment, under the conditions of the specificity of the development of the upper jaw and the impact of surgical interventions on it, requires detailing, which determined the purpose of this research. A three-dimensional 3D simulation model was created based on digital data of the spatial geometry of a sample of orthodontic appliance used for orthodontic treatment of children with congenital unilateral cleft lip and palate. Mathematical modeling methods were used to study the stress-deformed state of the appliance and estimate the magnitudes and distribution of the amplitudes of force reactions around its fasteners (clasps). Force reactions around of the supports of the orthodontic appliance when the screw is rotated from 0° to 360° (axial movement by 1 mm) are unevenly distributed, with a minimum value of force amplitudes of 10.3 N and a maximum of 30.9 N. It was noted that in the area of fasteners (clasps) placed more distally, the values are higher (30.9 N and 27.6 N) than in the medially placed fasteners (10.3 N and 12.5 N). It is also worth noting that on the side of the base of the appliance, which corresponds to the location of the small fragment of the jaw, the values of the force amplitudes are greater (30.9 N and 12.5 N) than on the side of the large fragment (27.6 N and 10.3 N). A significant dependence of the values of force reactions on the stiffness characteristics of the jaw and the type of force transmission from the orthodontic appliance to its areas was established. Keywords: 3D simulation model, force reactions, clasps.

Investigation of various pipe materials for riser operation in the arctic seas

А riser, which is an offshore water separation column is the main difference between offshore drilling and onshore drilling. The idea of the research is to calculate the stressed-deformed state of a riser made of various materials to identify technological advantages during drilling on the shelf and at sea in the Arctic. The article is the result of research conducted in the Mathematica application program to determine the operating stresses that depend on the drilling process conditions and the external environment. Modern drilling technologies are designed to increase the capacity of the equipment or to use alternative materials. Given the pace of development of the fields of the Northern Shelf of Russia, there is a need to explore the use of alternative materials for such marine equipment as risers.

Dependence of stress-strain state of hydraulic structures on infiltration moistening of foundation soils

As is known, loess subsidence soils are widespread on the globe; their area in Europe and Asia is more than 13 million sq. km. Many of the loess rocks are also located in Central Asia, including the Republic of Uzbekistan. The practice of irrigation development of loess lands shows that the disruptions that have occurred so far in the operation of hydraulic structures (HTS) are due to insufficient knowledge and neglect in designing the features of joint work and interaction structures with their subsidence foundations. The design of hydraulic structures also does not fully consider these features. To ensure the long-term, reliable, and economical operation of hydraulic structures on subsiding soils, it is necessary to improve their design and construction methods, considering the peculiarities of interaction with loess foundations. This article deals with the features of infiltration soil moistening from channels and structures on them. The article deals with the features of the infiltration moistening of soils from canals and structures on them. Based on the analysis of previous studies, the specificity of infiltration in loess soils is considered a serious factor affecting the stress-deformed state of hydraulic structures and their foundations.

Вибір параметрів ущільнення макета конструкції з листовим склом

Sheet glass is used in the creation of transparent constructions of building structures, for glazing of airplanes, helicopters, boats, as a structural material for instrument and aggregate construction, production of technical products in mechanical engineering. Structures made of sheet glass include fastening devices with sealing elements. Calculations of such structures cause difficulties, which are associated with the imperfection of their mathematical models. For the preliminary selection of the main parameters of the newly developed structures, it is advisable to use calculation software complexes with the preliminary development of the method of choosing the structure of fixing the glass sheet, taking into account the main sealing parameters according to the results of the study of the structure model. The nature of the stress state of the plate depends mainly on the type of load and the nature of its distribution, the ratio of the long and short sides to the thickness of the sheet glass, as well as the clamping parameters. The assessment of the stress-strain state of the structure is carried out according to the criteria of strength, rigidity and based on the study of dynamic characteristics. The calculations are reduced to justifying the choice of structural parameters of sheet glass, caliper and rubber sealing material, taking into account the stress-deformed state of the structure, operational, structural requirements and economic indicators. The paper presents a methodology for substantiating the selection of the parameters of a transparent structure, which includes a rectangular glass plate, elastic sealing and rigid frames based on model research in the SOLIDWORKS PC environment. It is shown that the parameters of fixing the sheet glass, including the sealing characteristics, significantly affect the mechanical properties of the structure. The developed model makes it possible to estimate the stress-deformed state of sheet glass and the dynamic properties of the structure depending on the parameters of the elastic seal.

MODELING THE INFLUENCE OF THE SHAPE OF THE LOCAL HEAT FLOW INTENSITY DISTRIBUTION ON THE SURFACE OF A SEMI-INFINITE BODY ON THE STRESS STATE IN THE VICINITY OF A SUBSURFACE CRACK

Purpose. A mathematical model to determine the two-dimensional thermoelastic state in a semi-infinite solid weakened by an internal crack under conditions of local heating is examined. Heat flux due to frictional heating on the local area of the body causes changes in temperature and stresses in the body, which significantly affects its strength, as it can lead to crack growth and local destruction. Therefore, the study of the problem of frictional heat is of practical interest. This paper proposes to investigate the stress-deformed state in the vicinity of the crack tip, depending on the crack placement. Methodology. The methods for studying the two-dimensional thermoelastic state of a body with cracks as stress concentrators are based on the method of complex variable function. Reducing the problem of stationary heat conduction and thermoelasticity to singular integral equations (SIE) of the first kind, the numerical solution by the method of mechanical quadrature was obtained. Findings. In this paper, we present graphical dependencies of stress intensity factors (SIF) at the crack tip on the angle orientation of the crack as well as forms of the intensity distribution of the local heat flux. The obtained results will be used later to determine the critical value of the intensity of the local heat flux from equations of limit equilibrium at which crack growth and the local destruction of the body occur. Originality. The scientific novelty lies in the fact that the solutions to two-dimensional problems of heat conduction and thermoelasticity for a half-plane containing a crack due to local heating by a heat flux were obtained. This would make it possible to obtain a comparative analysis of the intensity of thermal stresses around the top of the crack, depending on the form of distribution of the intensity of the heat flow on the surface of the body. Practical value. The practical value is the ability to extend our knowledge of the real situation in the thermoelastic elements of engineering structures with the crack that operate under conditions of heat stress (frictional heat) in various industries, particularly in mechanical engineering. The results of specific values of SIF at the crack tip in graphs may be useful in the development of sustainable modes of structural elements in terms of preventing the growth of cracks.

Stress-deformed state of a non-removable prosthesis on implants under mustering load depending on the angle of abutment wall tilt

Stress-deformed state of a non-removable prosthesis on implants under mustering load depending on the angle of abutment wall tilt

Numerical modeling of combined reinforcement concrete beam

Because polymer-composite reinforcements are a new material in construction, the possibilities of their use in load-bearing structures, including concrete beams, are somewhat limited by existing regulations. The research work implemented in this article is to study their strength and stiffness in cases where steel reinforcement is in the tensile zone and composite polymer reinforcement is in the compressive zone of concrete. Concrete beams with combined reinforcement are the object of the study, and the study of the stress-deformation state is its subject. The behavior of concrete beams with combined reinforcement under static load was studied. Considering the nonlinear properties of materials in the finite element method, their stress-strain states were investigated. A 3D beam model was created using the ANSYS Workbench 2022R1, and 3 series of samples were chosen and compared with hand calculations. The behavior of concrete beams with metal and composite reinforcement was carried out using numerical analysis. Also, the study’s results show that the role of the reinforcement installed in the compressive zone of the beam is better than the performance of the beam without the reinforcement installed in the compressive zone. Although the failure starts with the rebar in the tensile zone, the rebar installation in the compression zone shows an increase in the bearing capacity and stiffness of the beam.

METHODS AND RESULTS OF STUDYING THE DYNAMIC STATE OF THE GEOLOGICAL ENVIRONMENT OF THE URBANIZED AREA (USING THE EXAMPLE OF THE YEKATERINBURG METROPOLIS)

The types and qualitative and quantitative characteristics of man-made phenomena in a significantly urbanized territory are largely determined not only by the man-made load, but mainly also by the fact that the earth's crust within this territory is in geological, structural-tectonic, geomorphological, engineering-geological, dynamic and other natural relations. About 1.5 million people live on the territory of one of the largest Yekaterinburg metropolis in Russia with an area of more than 1000 km2 and, having a complex surface relief, there are a huge number of gigantic industrial enterprises for various production purposes, a metro, four pond reservoirs. Consequently, the level of technogenic load on the geological environment is very high here. Therefore, relevant in scientific, practical and social-ecological relations is the task of studying its natural dynamic state in order to subsequently predict negative dynamic events within its limits in the form of man-made earthquakes, mountain impacts, etc. This is the problem of this article. In a substantive and methodological respect, the study of the natural dynamic state of the territory of the metropolis consists in the consideration and analysis of such important factors as: the geological and structural-tectonic structure of the geological environment, its seismicity, the nature of modern movements of the earth's surface and the natural stressed-deformed state due to tectonic and gravitational (density heterogeneity of the geological environment) forces.

Математичне моделювання напружено-деформованого стану моделі колінного суглоба при аплазії хрестоподібних зв’язок та після відновлення зв’язкового апарату

Defects in the establishment and development of the cruciate ligaments are one of the main causes of the instability of the knee joint in congenital longitudinal defects of the development of the lower limbs. This pathology occurs with a frequency of 0.017 per 1000 newborns. The absence of cruciate ligaments leads to a change in the shape of the articular surfaces of the knee joint, and is formed due to hypoplasia of the femoral condyles, the absence of the intercondylar fossa of the femur, and the absence of the intercondylar elevation of the tibia. Purpose - to study the stressed-deformed state of the knee joint with aplasia of the cruciate ligaments before and after reconstructive interventions and to compare the obtained results with the norm. Materials and methods. A basic finite-element model of the lower limb was developed, which was supplemented with collateral and cruciate ligaments of the knee joint. On the basis of the basic model, a model with aplasia of the cruciate ligaments of the knee joint and a model reflecting the state of the knee joint after reconstructive surgery using the SUPER KNEE method according to D. Paley were developed. The model was tested under the influence of a vertical load in the position of bending the knee joint at an angle of 135. Results. The results of the mathematical modeling showed that the aplasia of the cruciate ligaments leads to an increase in the stress level, both in the bone elements of the model and in the elements of the ligamentous apparatus. Restoration of the ligamentous apparatus of the knee joint with artificial materials according to the SUPER KNEE method according to D. Paley allows to reduce the stress level in the bone elements of the model, while the stress in the femur is determined to be lower even compared to the normal model. Ligaments made of artificial material assume the main loads in the knee joint, and ensure an even load of mylar tape on both sides of the joint. The high level of stresses in mylar tape compared to normal ties is due to the higher modulus of elasticity of the material and its lower plasticity. Conclusions. Aplasia of the cruciate ligaments leads to an increase in the stress level, both in the bony elements of the model and in the elements of the ligamentous apparatus. Restoration of the ligamentous apparatus of the knee joint allows to reduce the stress level in the bony elements of the model with ligament aplasia, and brings the values closer to the parameters of the normal model. Tensions in the ligamentous apparatus of the knee joint after its restoration increase significantly, which is due to the mechanical properties of the artificial material that replaces the ligaments. The increased level of stress that occurs in the mylar tape indicates that it firmly holds the load arising in the joint. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. No conflict of interests was declared by the authors.

Біомеханічне обґрунтування вибору засобу фіксації кісткових фрагментів при проксимальній остеотомії першої плеснової кістки

One of the most common pathologies that occurs in static deformities of the anterior joint of the foot in the foot is valgus deformity of the first toe. Distal or diaphyseal osteotomies are used for mild degrees, and proximal osteotomies for severe ones. Spikes, screws or plates with angular stability are most often used to fix bone fragments. Purpose - with the help of biomechanical studies, to study the stress-deformed state of the foot model with different options for osteosynthesis of the first metatarsal bone after the proximal osteotomy. Materials and methods. Mathematical modeling of osteosynthesis of the first metatarsal bone during correction of valgus deformity of the first toe using proximal osteotomy was carried out. Three variants of osteosynthesis were modeled: Kirschner pins, screws, and a bone plate. Results. During osteosynthesis with spikes, maximum stresses of 2.1 MPa occur in distal fragment. In the proximal fragment, the stresses are twice as low - 1.2 MPa. The tension in the resection zone is 0.1 MPa. During osteosynthesis with screws, the stresses in the proximal and distal fragments of the bone are almost the same, and are 0.9 MPa and 0.8 MPa, respectively. The tension in the osteotomy zone is 0.1 MPa. Osteosynthesis with a bone plate provides a low level of stresses in the osteotomy zone - 0.1 MPa, as well as an even distribution of stresses between the proximal and distal fragments of the metatarsal bone - 0.8 MPa and 0.7 MPa, respectively. During osteosynthesis with spikes and screws, the relative deformation of the bone regenerate does not exceed 0.13%. During osteosynthesis with a bone plate, this figure reaches 0.5%. Conclusions. For osteosynthesis of bone fragments during proximal osteotomy of the first metatarsal bone in order to eliminate valgus deformity of the first toe, spikes, screws and a bone plate can be used. All investigated types of osteosynthesis provide a low level of stress in the osteotomy zone of the first metatarsal bone, but, according to the criterion of stress values in the proximal and distal fragments of the bone, osteosynthesis with spikes showed the worst result, and osteosynthesis with a bone plate showed the best. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

INFLUENCE OF METAL LAYER SURFACED WITH LOCAL ADDITION OF AMPLIFER ON THE STRESSED AND DEFORMED STATE OF THE PLATE

One of the important aspects of the surfacing process, both restorative and strengthening, is the formation of metal layers that differ significantly in physical and mechanical properties from the base. At the same time, the local action of a concentrated heat source causes uneven heating of the workpiece in thickness, and the crystallization of the deposited layer is accompanied by casting shrinkage and structural transformations, the stress-deformed state of such objects will be quite unfavorable both from the point of view of forming and the subsequent operation of the finished products. In view of this, based on the methods of the theory of elasticity, develop an algorithm for analytically determining the stress-strain state of a welded plate of considerable width as a composite two-layer material under the influence of external normal loading, taking into account the location of zones of increased hardness in the form of strips in the welded layer. The surfaced prismatic plate was adopted as a two-layer structure, in which the deformations of the material are directly proportional to the stresses. The deposited layer is continuous. The thickness of the plate and the deposited layer are unchanged. By using the dependences of the stress-strain state indicators on one stress function, a mathematical model of the welded plate as a two-layer structure was formed. An algorithm for determining the deformations and distribution of stresses in the plate under the condition of its flat deformation in the direction of surfacing is constructed. The periodic change of the modulus of elasticity of the deposited layer is taken into account. The indicators of the stress-strain state of the plate from its normal load were determined. The effect of Poisson's ratio on the layer-by-layer distribution of stresses in the plate is shown.

The study of plastic deformation in the pair of ball-seat of oil well pump

The paper analyzes the operation of unit of seat-ball on oil well pump. The stressed-deformed state of seat-ball has been theoretically studied. It was established that one of the major reasons for the breakdown of the valve unit is the deformation of seat edge. Considered the mentioned above, a design of valve unit allowing eliminating the probable deformation of the seat from ball beat is offered. The design offered has been tested and initial positive results obtained as well.

FEM analysis of the stress strain rate during hot forging of steel non-rotational form

The simulation of the clutch lever forging process was carried out using Qform software, which is based on numerical and finite element methods, while the tool itself was modeled in SolidWorks CAD software. The stress-deformation state of the workpiece in the process of hot forging in an asymmetric dies for forging with excess material, which represents one of the most common technologies in modern industrial processes of the metalworking industry was analyzed and monitored in this paper.

Investigation of stress-strain state of pipeline hoist taking into account installation displacements

Stress-deformed state of a technological equipment at oil and gas refinery facilities has an ambiguous character and may depend on such factors as, for instance, operating conditions, design feature, material degradation rate, different deviations during assembly and installation etc. Moreover, the maximum level of working stress can be changed either according to linear or nonlinear laws depending on operating machinery and determining parameter of technical condition. This aspect is highly important at forecasting the further safe operation. In a modern world it is very important and urgent to build up equipment model and its parts which are digital analogue of a real facility. Application of such digital models allows to forecast future behavior of facility at the present and for the future depending on change rate of specific parameters, to determine positive and negative schemes from high stress formation point of view in the structure. Such digital model can be applied on each stage of an equipment service life and make forecasts of an equipment transfer to critical state, to determine possible reasons of changes and to carry out prevention activities. This article considers the stress-deformed state of a technological pipe operated under vacuum at different locations of its fixation on nozzle pipes of technological apparatuses.

Assessment of interaction the new construction object at full load and the surrounding building in the dense urban development conditions

The work is devoted to research the impact of a new building at full load after completion of its construction has been investigated through an assessment of the interaction with the building envelope, the ground mass of the base and the foundation of the existing five-story building, in comparison with the assessment of the impact of a deep excavation in the process of engineering preparation for this construction, based on the developed methodology for studying the interaction of new construction objects and nearby buildings in complex engineering and geological conditions and dense development conditions.
 For numerical studies of the stability of the combined space, the proposed methodology has been used, which is built on the initial relations of the variational equations of equilibrium and the equation of the load surface in the six-dimensional stress space, which is a development of the theory of the limit stress state of the soil half-space based on the introduction of an extended yield criterion for a plane problem of the nonlinear theory of elasticity and plasticity, which provides for the determination of the value of the second critical load, at which solid sections of the ultimate stress state appear in the soil half-space.
 From the analysis of the movements of the nodes located on the vertical face of the «wall in the soil» structure (retaining wall of the pit), it can be concluded that the transverse displacements of the retaining wall compared to the calculations according to the first option have changed to the opposite, which is associated with the formation of a sliding prism under the passive pressure on the retaining wall from the side of the pile foundation of the new building. This indicates a change in the stress-deformation state of the soil base of the existing building, from the influence of the deep excavation during the construction process, which was evaluated according to the first version of calculations, to the impact of the new building after the end of construction, which was analyzed according to the second version of calculations. In this way, the change in the stress-deformation state of the main urban building is determined, which is a criterion for determining the impact of adjacent construction in the urban area on the condition of the ground bases and foundations of adjacent buildings, their preservation and ensuring safe operation.