Introduction. Modern industrial development of the territories of Siberia and the Far East is carried out primarily due to the intensive construction of main overhead power transmission lines (overhead lines) with a voltage of 220–500 kV. Solving the issue of the actual operation of the structures of supports and foundations is of high relevance to ensure the required reliability of power supply to responsible consumers in severe climatic and transport remote conditions. The movement of foundations in weak soils leads to a significant change in the stress-strain state of the above-foundation structure, creating emergency damage and incidents on overhead lines. However, the modern design of overhead line supports is carried out separately for foundations and above-foundation structures. The object of the study is steel standard lattice overhead line supports of a new unification, and the subject of the study is the interaction of structures, foundation and basement in structures such as lattice overhead line supports.

Materials and methods. A literary review on the interaction of structures, foundations and the ground base of steel overhead line supports aws performed, including an analysis of experimental and theoretical results on this topic, indicating the absence of a unified calculation methodology for the “structures, foundations and ground base” system for overhead line supports based on the use of modern software systems. The results of field tests of overhead line supports with foundations on ground basess, conducted in 1979–1980 with the participation of the author, are presented, indicating significant movements of foundations under loads of the main design modes.

Results. As a result of the calculation of such systems with foundations on a deformable soil base using modern software systems, new results were obtained that differ significantly from those obtained during field tests on a rigid power floor or on fixed foundations.

Conclusions. Performing calculations of structures of supports and foundations in the “construction – foundation – base” system provides a more accurate design of structures for each picket of the route, the so-called individual design, which will significantly reduce the consumption of steel and concrete compared with standard design, as well as increase the reliability of structures of supports and foundations of overhead lines.

Introduction. The use of full probabilistic methods for assessing and analyzing the structural reliability level is a logical stage in the evolution of current methods, which are called semi-probabilistic or deterministic. Full probabilistic methods make it possible to obtain a quantitative assessment of the structural reliability in the form of failure probability and to compare the safety of different types of structures made of different materials in one system.

Materials and methods. The paper presents methods of data simulation based on statistical information about random parameters in mathematical models of limit state of steel trusses. The advantage of the method of data simulation is the simplicity of programme realization in widespread programme complexes and stability of the result in the case of nonlinear limit state models and a set of different probability distribution functions of random variables. Also, instead of conservative representation of the design scheme of the truss as a sequential system of independent elements (bars), it is proposed to take into account the peculiarities of steel truss design and to specify the failure models of the whole system, which will allow to obtain a more objective assessment of the structural reliability level in the form of failure probability.

Results. The numerical example shows the necessity of taking into account the coefficient of variation of steel strength of the truss bars in reliability analysis, because even if the requirements to the normative strength of steel are met, the influence of the coefficient of variation on the probability of failure remains significant. Estimation of failure probability of both individual truss bars and the truss as a whole as a system allows to perform technical and economic comparison of design variants and optimization of technical solution taking into account the reliability factor.

Conclusions. The proposed approach to probabilistic design makes it possible to quantitatively express the level of reliability of a steel truss, as well as to predict its change with time. The use of probabilistic methods of designing and analyzing the reliability of structures allows for a more detailed study of the operational safety of buildings and structures. The use of direct statistical data on snow loads from meteorological stations and on the indicators of bearing capacity of elements from manufacturing plants will allow to obtain a more economical solution by specifying random parameters.

Introduction. Finding the bearing capacity of compressed columns subjected to a combination of effects (normal static and transverse dynamic loading), including emergencies and taking into account the actual condition under various corrosion and other environmental effects, is a relevant though understudied problem. It requires analytical methods, labor-intensive finite element models, and a great number of parameters that should be taken into account.

Materials and methods. The solution was obtained analytically. The finite element model was developed in a 3D formulation to evaluate the applicability and convergence of results. Analytical results were compared with those obtained experimentally.

Results. An analytical technique was developed for the approximate evaluation of the bearing capacity of centrally compressed corrosion-affected reinforced concrete columns under transverse impulse loading in an emergency situation. The results obtained analytically were compared with the results of finite element modeling and well-known full-scale experiments that involved a specific column attachment pattern. A discrete-time model is proposed to take into account corrosion damage in 3D finite element schemes. This model is based on the parabolic law of mechanical characteristics of concrete that deteriorate along with the depth of corrosion propagation.

Conclusions. The authors found that a greater corrosion damage to concrete leads to its non-plastic destruction in the case of exposure to emergencies, and deeper corrosion damage under great compressive loading leads to the local loss of stability of reinforcement bars in the zone affected by transverse impulse loading and a great reduction in the column resistance to progressive collapse. The practical applicability of the proposed engineering method is proved for the range of relevant values of compressive loads.

Introduction. The relevance of the development of analytical models describing nonlinear deformation of concrete under conditions of complex stress state is due to their importance both in theoretical and applied aspects. The key factors that should be taken into account when creating such models are the heterogeneity of concrete material properties, its structural change under loading, the occurrence of cracks, as well as phenomena associated with non-equilibrium processes occurring in concrete over a long period of time. The main objective of the study is to create an analytical model of the deformation diagram of concrete that allows an accurate description of the nonlinear behaviour of concrete under uniaxial, biaxial and triaxial loading conditions. This model should be versatile and easy to use. It is important that the model allows analysis and reflects as accurately as possible the results obtained from experiments with concrete of different strength classes.

Materials and methods. In the process of forming a model that shows the behaviour of concrete considering uniaxial stress state, it was decided to include a fourth order polynomial function in the work. Which is because it is suitable to perform an approximation that has a relationship between stresses and relative strains. After obtaining the model of concrete deformation under uniaxial stress, it was involved in the process of forming the constitutive relations for the volumetric stress state as a basis.

Results. An analytical nonlinear formula was formed to determine and show the existence of the dependence between stress and relative deformations of concrete under uniaxial loading conditions. To visualize this dependence, a continuous polynomial function is used, which describes the behaviour of concrete at any degree of deformation. It also contains a descending section of the diagram, which shows, in particular, the ultimate deformations. The given analytical dependence can be used as a basic component in establishing the characteristics and properties of concrete within the framework of the formulation of determining relations as a descriptive method to indicate the deformations of concrete under volumetric stress state.

Conclusions. The analytical relationship can be used in the form of key characteristics that define and describe the properties of concrete within the engagement of fundamental equations representing the behaviour of concrete under volumetric stress state. This method is quite accurate and will be an excellent solution when carrying out the design of reinforced concrete structures in the field of engineering.

Introduction. Knowledge of the key parameters that determine the operation of load-bearing systems makes it possible to ensure safe, rational and economical operation of buildings and structures. The paper defines the relative generalized parameters that determine the operation of composite membrane structures for membrane systems with a concrete layer placed on the membrane.

Materials and methods. Membrane systems with a rectilinear support contour rigidly fixed on supports and a flat steel membrane attached to it are considered. The calculations were performed for the construction of two dimensions in the plan. The first one is: a = b = 6 m with a membrane thickness of 1 and 2 mm. The second one is: a = b = 12 m with a membrane thickness of 2 and 3 mm. A layer of concrete B30 is laid on the membrane, equal to 50 and 40 mm for the first model, and 100 and 60 mm for the second. The structure along the free edge of the membrane is loaded with a load q acting in the plane of the membrane.

Results. Numerical calculations performed using the finite element method have shown that an increase in the relative longitudinal stiffness of the concrete layer leads to a decrease in bending moment, longitudinal forces in the contour and stresses in the membrane. This increases the rigidity and load-bearing capacity of the structure. It was found that by changing the stiffness parameters of the concrete layer, the efficiency of the structure can be significantly improved.

Conclusions. The placement of a concrete layer on the membrane significantly increases the operational reliability of the structure, reduces forces in the support circuit, and reduces deflections and stresses in the membrane. The relative generalized parameters of membrane systems with a concrete layer can be used to assess the stress-strain state of sagging membrane coatings on a rectangular plan with a flat support contour.

Introduction. When sea wave energy converters are designed, floating buoys, being part of their structure, must be reliably anchored to the bottom. To date, numerous engineering solutions are developed towards this end. They feature various methods of fixing floating buoys to the bottom (weights, anchors, and sinkers).

Materials and methods. The vacuum anchor is designed to fix floating buoys, or sea wave energy extractors, to the soil of the sea bottom. The goal of the study is to substantiate the engineering solution to use vacuum anchors for sea wave energy converters, designated for temporary coastal construction facilities. Methods of theoretical and experimental research, identification of domestic and foreign sources, analysis and comparison of data were employed to achieve this goal.

Results. The article presents conceptual schemes of vacuum anchors to be embedded in weak soils. The authors offer an engineering solution and analyze the holding capacity of a vacuum anchor. As a result of experimental studies, the value of the static friction coefficient is found on the surface of a polymer vacuum anchor in silty waterlogged soil. This coefficient allows analyzing the immersion of vacuum anchors in weak soils and the pullout of vacuum anchors from weak soils. The authors describe the technology of vacuum anchor immersion in weak bottom soil; analyze conditions for the anchor immersion in the weak soil of the bottom, and conditions for the anchor pullout.

Conclusions. Vacuum anchors, designed for weak bottom soils, have a great holding capacity, relatively small dimensions and cost, including the cost of construction and embedment. Their practical application will reduce the cost of (1) foundations made for floating sea wave energy extractors and (2) energy transformation into useful power in various process flows designed to generate energy for coastal construction facilities.

Introduction. The expediency of increasing the accuracy and generality of simplified solutions for calculating the settlement of single piles is shown. Such solutions are recommended by the building codes of the Russian Federation for assessing the value of the design settlement of piles, and are also used to determine the parameters of contact models in the development of pile foundation structures.

Materials and methods. The theoretical analysis and comparison of calculation methods based on the approximation of pile work in an elastic half-space are performed. A verification and update of the dependencies of the main analytical solution based on the telescopic scheme of the elastic massif containing the pile is developed. Comparisons of the calculation results by various methods are presented.

Results. The analysis revealed a number of discrepancies depending on the parameters of the piles and the soil base. Recommendations for the application of the considered solutions are developed and the area of their application is established — assessment of the initial linear resistance of the pile and the corresponding parameters of the contact model used to design the pile foundation.

Conclusions. Simplified solutions for calculating the settlement of single piles are in demand in construction practice; increasing the accuracy and generality of such solutions ensures the definition of adequate parameters of contact models for developing reliable and rational designs of pile foundations. The scope of the updated solution is the assessment of the initial linear resistance of the pile. The advantage of the updated solution is the clearly identified share of the pile heel, which allows for a separate assessment of the work of its lateral surface, in particular in current problems with a pull-out load on the pile or by taking into account the “switching off” of the pile heel due to loose slurry under the heel of a bored pile.

Introduction. Construction of transportation lines and auxiliary structures of an underground railway is often cumbersome due to the requirement not to exceed maximum values of subsidence and tilt of buildings and structures in areas affected by new construction projects. Compensation grouting is the action that decelerates soil deformations and prevents the subsidence and tilt of buildings and structures from exceeding the limit values. The study focuses on the formulation of and the analytical solution to the problem of the stress-strain state of the soil mass that has weight and that is located beyond the excavation shoring, if depth equals h, distributed strip load q is constant, width b equals 2a, depth equals d, and the distance from the edge of the pit retaining wall equals c.

Materials and methods. A solution to the E. Melan problem was applied to obtain normal and tangential stresses to solve the problem of the stress-strain state of the soil mass that has weight and that is located beyond the excavation shoring, if excavation depth equals h, distributed strip load q is constant, width b equals 2a at depth d, and the distance from the edge of the excavation shoring equals c. Hooke’s law was applied to find the soil mass deformation.

Results. An analytical method was developed to make a quantitative assessment of the stress-strain state of soil under the action of compensation grouting. Isofields of stresses and deformations were obtained to find values of soil uplift and to evaluate the compensation grouting effectiveness.

Conclusions. An analytical solution to the E. Melan problem was applied to solve the problem of injection pressure, acting upward and downward near the excavation shoring, and to derive formulas needed to find components of normal and tangential stresses. The solution analysis shows that the injection pressure, acting upward and downward near the excavation shoring, greatly affects the stress-strain state of the entire soil mass, while large horizontal stresses may occur in the excavation shoring. This issue must be considered in the course of analyzing the strength and stability of excavation shoring.

Introduction. Prefabrication and modular construction, as tools for increasing the pace of construction production, are becoming more and more in demand for the construction industry in the current economic environment due to the efficiency of installation and the ability to shorten project deadlines. However, despite these advantages, the use of information modelling technologies for automating the design processes of modular facilities and calculating technical and economic indicators remains at an insufficient level, since the potential of TIM in this area has not yet been fully realized. Therefore, it is advisable and necessary to automate the processes of various stages of the life cycle, including the calculation of project indicators for factory production. It was concluded that it is advisable to develop a predictive model that reduces the design time and increases the economic feasibility of prefabrication.

Materials and methods. The practice of automation of design processes based on BIM, in particular in the framework of factory-based production of modular structures is considered. The purpose of this study is to increase the efficiency of solving the life cycle management tasks of modular objects through the use of a predictive model using the statistical calculation of the TEI project for more rational data management at various design stages. To achieve this goal, a systematic review of approaches and tools for automating modelling and information processing processes was conducted.

Results. As a result of the analysis, a model was developed, the results obtained were analyzed, and the possibilities and advantages of applying this model within the framework of prefabrication were presented. Ways of further research within the framework of modular object design methodology were formulated.

Conclusions. The proposed data model can systematize and predict the TEI of prefabricated modules with sufficient accuracy based on IM and integration of statistical calculations, which improves decision making in the early stages of design, and helps to reduce the risk of errors and reduce the cost of redesign.

Introduction. In 2024, regulatory legal acts established the mandatory development of design documentation containing a building information model (BIM). These changes directly affect approaches to the formation of estimate documentation, providing opportunities to automate this process. Despite significant progress in automating the formation of bills of quantities (BOQ), automated pricing has not yet been widely implemented. The main objective of the study is to systematize and summarize the current methodological documents regarding the formation of estimates in design using information modelling technology, approved at the level of the city of Moscow, and consolidate their provisions into a single concept that facilitates the implementation and widespread use of automation of obtaining estimate documentation.

Materials and methods. The study used methodological documents regulating the development of design and estimate documentation using building information modelling (BIM); Territorial estimate standards for the city of Moscow at the basic price level as of January 1, 2000 (TSN 2001); Moscow system of classifiers (MSSC).

Results. Based on the provisions of the methodological documents mentioned in the previous section, the concept of automation of the formation of estimates during the development of project documentation using BIM is presented. The main stages necessary for the automated assignment of prices are described. An algorithm for comparing BIM with parameterized prices is presented.

Conclusions. Conclusions are made about the advantages of automating the comparison of prices and elements of the BIM. Further steps are defined to facilitate the implementation and wider dissemination of the automation of obtaining estimate documentation based on digital information models.

Introduction. The aim of this study is to test the possibility of using a hardware-software solution including the application of artificial intelligence algorithms and technologies for visualization of TIM models in the modes of augmented (AR), mixed (MR) and combined (AMR) reality in the conditions of capital construction, as well as to test the hypothesis that this solution will increase the accuracy and efficiency of control, improve process management and reduce costs by reducing the number of reworks.

Materials and methods. The tests were carried out by the scenario method, which provides for the consecutive passing of tests corresponding to the real conditions of use: from site preparation and checking the possibility of comparing the 3D digital model with the physical object to the formation of the final reporting documentation.

Results. The hypothesis about the accuracy of detection of geometrical discrepancies in the equipment before its transportation to the construction site, stability of the platform operation in the conditions of real construction control with the use of augmented and mixed reality technology were tested. The economic and time efficiency of the system due to automation of
the processes of deviation detection and reporting has been evaluated.

Conclusions. The experiments demonstrated that the technology allows to visually combine the TIM-model and the real object, simultaneously automating the process of deviation detection and generating reports available for analysis both on the site and in the office. Such transparency and speed of information exchange enable faster decision-making and timely involvement of all interested specialists in the elimination of discrepancies.