The use of a solid analog and the involvement of an appropriate theory of stability made it possible to perform mathematical modeling and determine the parameters of the critical state of cylindrical mesh shells depending on the geometric characteristics and the number of half-waves of the shape of the loss of stability. The values of the critical load of cylindrical mesh shells are determined taking into account geometric and force factors. According to the results of calculations, the patterns of changes in the number of half-waves of the form of loss of stability and obtaining the minimum value of the critical load under the condition of maximum approximation of flexural and membrane stiffness are revealed and analyzed. A numerical example is shown in which the values of critical load and stiffness are determined, taking into account possible forms of loss of stability. The patterns of changes in these indicators for a given number of half-waves are established and analyzed.

Keywords: cylindrical mesh shells, mathematical modeling, critical load, stability, stiffness, number of half-waves

This study will examine the historical formation of the architecture of places of detention. The author gives space to the volumetric and planning transformation of prisons, examines the history of their emergence in stages and reveals the connection of these changes with the changes in the state and society as a whole. The study deals with the issues of restraint of freedom from inside and outside the penitentiary institutions, and partially touches upon the connection between fortification and penitentiary institutions in the sense of the continuity of the urban, architectural and landscape planning techniques of defence used. The study also presents examples of modern layouts; the types of layouts and the architectural means and techniques used in them to create a safe and comfortable environment are summarised in a table as material for analysis. In addition, as the results of the study, the main issues and directions of further development of prison architecture are indicated, and the author proposes models of optimal architectural and planning organisation in terms of security, surveillance and access control.

Keywords: security, prisons, penitentiary architecture, architecture, detention centres, design

In the construction sector, the reform of design and survey work allows us to take a fresh look at the state of engineering and geological research. The use of software systems provides an opportunity to automate this process during construction, reconstruction of buildings and structures in order to avoid the formation of landslide processes and reduce man-made risks. Limit equilibrium methods are used to determine the stability of a slope or an underground structure. Therefore, the purpose of the study in the article was to conduct engineering and geological surveys using various methods and then calculate the stability of landslide slopes. The sliding surfaces with the lowest coefficients of stability margin were selected by the optimization method for the calculated slopes.

Keywords: integration, reformation, method, construction, soil, landslide slope, man-made risk, surveys, automation

The paper discusses the use of carbon fiber composite materials for reinforcement of specimens made of pipe sections in tension under the action of internal pressure. Experimental investigations of steel pipes under the action of internal pressure both without reinforcement and with different number of reinforcement layers with carbon tape are described. The main interest is in the joint operation of the pipe wall and external reinforcement elements. Significant influence of external reinforcement on stiffness and deformability of the specimens is noted.

Keywords: high-strength fiber, carbon fiber, carbon tape, adhesion layer, pipe, external reinforcement system, polymer composites, tensile strength

Indirect reinforcement can significantly increase the strength and deformation characteristics of concrete. For the compressed zone of reinforced concrete beams, one of the most effective options for indirect reinforcement is transverse welded mesh. At the same time, the current regulatory documents still have a number of gaps in the methodology for calculating such structures. The article presents experimental data and calculation results for three series of reinforced concrete beams with indirect reinforcement of the compressed zone. Based on the calculation results, the shortcomings of the normative methodology are shown when performing calculations within the framework of the theory of limit states and assigning design values ​​for the strength of concrete with indirect reinforcement. Conclusions are drawn about the necessary sequence for calculating the design strength and deformation characteristics of concrete with indirect reinforcement.

Keywords: indirect reinforcement, beam, welded mesh, volumetric stress state, nonlinear deformation model, stress-strain diagram

To develop a methodology for assessing the strength of ring flanges, research was conducted on the load-bearing capacity of welded pipe joints of varying diameters. The study employed the component finite element method (CFEM) implemented in the IDEAStatiCa Connection software. To verify the obtained results, a numerical experiment was carried out using the ANSYS software package. The investigation considered several types of flange joints made from welded pipes with different diameters. Parameters were selected based on common sections used according to russian Series 3.400-8 (Issue 2). The study found that for all cases, the highest stresses occurred on the flange at the joint with the smaller diameter pipe. The analysis indicated that the CFEM's applicability should be limited to diameter-to-wall-thickness ratios (D1/t1) of up to 40. Beyond this threshold, the CFEM does not accurately predict the strength of the joints due to the significant deformation that occurs in the pipe walls, forming a truncated cone shape at the flange junctions. For practical applications, formulas are proposed to check the strength of ring flanges. These formulas account for the weakening of the plates by bolt holes and provide conservative results. The findings highlight the necessity for additional numerical and physical experiments to refine the methodology for cases with D1/t1 ratios exceeding 75. The proposed approach offers a practical solution for evaluating the strength of ring flanges in welded pipe joints of varying diameters, contributing to the development of relevant engineering standards.

Keywords: load-bearing capacity, ring flanges, welded pipes, assembly joints, strength, component method, numerical experiment

Framed fabric roof structures of the sawtooth-type are considered. The structures are arranged on rectangular plan. They consist of a number of sectors which are separated by arch-shaped supporting ribs. The sectors are covered with a prestressed soft shell. Geometric nonlinear static analysis of the shell is performed taking into account the effect of snow and wind loads. The general dimensions of the shell and the prestress value are considered as the primary variables. Quantitative assessment of deformation of the shell is carried out by means of so-called deformability index. The index is reciprocal to the relative deflection. A functional expression for approximating the deformability index is proposed. The expression is to be used at the stage of developing the design solutions for fabric structures. The coefficients of the function are found by means of the least squares method. The guidance for assigning the main parameters of the sawtooth-type fabric structures are given.

Keywords: fabric structure, roof structure, soft shell, sawtooth roof, geometric parameters, prestress, deformability, approximation

This research presents the methods and conclusions obtained from modeling a composite wall panel with a wooden frame and polystyrene concrete core in the Lira-SAPR program, used in the construction of low-rise buildings for residential and commercial purposes. The findings were compared with the results of panel tests at the research laboratory of the Pacific State University (hereinafter TOGU).

Keywords: linear calculation, panel construction, low-rise construction, LIRA-SAPR, modeling

Indentation is a universal and practical method for obtaining material characteristics, especially when it is impossible or difficult to expose the material to other measuring methods. Experimental data on the mechanical properties of various types of materials were obtained using the shock loading unit. A mathematical model based on the finite element method was used to verify the experimental results. The article considers the solution of the problem of classification of neural metals with different mechanical properties. As part of the work, an artificial neural network has been created that allows the distribution of materials into selected groups. It is determined that a significant advantage of using neural networks is the ability to process experimental data and identify complex nonlinear dependencies, which makes them in demand in tasks related to the study of material properties.

Keywords: impact indentation, neural network, task of classification, artificial intelligence, dynamic indentation, non-destructive testing.

The public education project ""Dream School"", implemented in support of the federal school overhaul program, attracts students of architectural and design schools in the regions, which will allow them to simultaneously acquire applied competencies in the learning process. During the development of the design project, the need for specialists to conduct a preliminary design analysis was revealed, since one of the five schools did not meet the standards in terms of their spatial planning parameters. It is proposed to carry out the reconstruction of this educational institution. The premises of the dining room and the assembly hall are transferred to the annex block.

Keywords: school design project, school renovation, school recreation, public education project "Dream School", school reconstruction

In the paper, parametric equations of right conoidal surfaces with an orthogonal coordinate system with different guiding curves are obtained for the first time. Parametric equations for conoids with guide curves sine, cosine and parabola are presented. In the MathCad system, the constructions of right conoids with selected guide curves with various initial geometric parameters are visually performed and presented in the paper for the possibility of expanding their use in architectural design, construction and other industries.

Keywords: conoid, orthogonal coordinate system, sine, cosine, parabola, parametric equation, MathCad system

The article discusses the design features of wooden buildings constructed from cross laminated timber panels (CLT). CLTis a new material widely used in wooden house construction. The panels are used for the construction of multi-storey buildings and replace traditional frame and cobblestone wooden houses. The article analyzes the advantages of using CLT in modern construction, discusses various types of joints, such as butt joints, corner joints, as well as their advantages and disadvantages. Special attention is paid to panel mounting methods that ensure the reliability and durability of the structure.

Keywords: wooden structure, wood, cross-laminated timber, CLT panel, nodal connection, connection system

The article presents calculations of energy costs when carrying out major renovations of a building. Based on the obtained values, the structure of fuel and energy resources expenditures by subgroups of repair and construction work was formed. The presented research results are based on the calculation and comparison of the obtained energy consumption values ​​in proportional units - kilograms of standard fuel. As a result of the study, the highest energy consumption was established, which is accounted for by the consumption of liquid fuel in comparison with electricity, which is due to the specifics of the machines and mechanisms used (truck crane, truck, etc.), as well as the chosen technology of repair and construction work. In order to account for and minimize energy costs during the period of major repairs, it is also proposed to monitor the consumption of fuel and energy resources.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

Paper presents an algorithm for analyzing and controlling data and project quality in construction using building information modeling and extensible markup language. The authors, argue that project quality stems from data quality and information quality. The proposed algorithm integrates BIM with extensible markup language, converting data quality and project quality criteria from employer information requirements into an extensible markup language scheme to ensure compliance with established standards. Key criteria for data quality and project quality include classification, identity, hierarchy, information identity, coordination, level of development , association, redundancy, staging, and spatial orientation. The algorithm involves creating a test BIM model, to simulate employer information requirements violations, performing checks using a Model Checker, automation tool in Autodesk Revit, and ensuring all criteria are met. The process includes saving verification checks, combining them, and generating reports in comma separated values format for transparency and further analysis. The authors highlight the importance of applying the algorithm from the early stages of project discussions, involving all participants to ensure the accuracy of data quality and project quality schemes. This approach leverages both international and domestic standards for continuous monitoring and immediate decision-making support throughout the project lifecycle.

Keywords: extensible markup language, information technical requirements, employer information requirements, building information model, information quality, project quality, model checking

The article is devoted to the study of the main methods of ice crossings and their reinforcement. Key concepts related to this type of transportation are considered, including the definition of an ice crossing, its role in the transportation infrastructure, and the conditions necessary for its construction. Special attention is paid to the preparatory work carried out in summer and the main work carried out in winter. The methods of ice crossing reinforcement are described in detail, including thermal reinforcement, use of logs, snow reinforcement and use of geosynthetic materials. The advantages and disadvantages of each method are discussed, as well as factors influencing the choice of a particular reinforcement method.

Keywords: ice crossing, reinforcement

The article contains the methodology and results of theoretical and experimental studies of the stress-strain state of a conical radial-beam dome with triangular shell elements. The results obtained by various methods are analyzed and compared. The triangular membrane panel is part of the radial beam dome structure and consists of a support frame and a steel membrane in the shape of a triangle. The shape of the triangle forming the membrane panel can be different and depends on the number of ribs in the radial beam dome. The supporting contour is a compressed-bending element of the dome and is made, as a rule, from a rolled steel profile with a channel section. The membrane is made of thin steel sheet and attached to the upper flange of the channel with self-tapping screws or spot welding. To assess the strength and deformability of a steel membrane sheet, its operation under the action of a uniformly distributed snow load, an unevenly distributed snow load and a concentrated installation load was considered. Several options for nonlinear static calculations in various computer systems are shown.

Keywords: building structures, wooden structures, membrane panel, stress-strain state, radial beam dome, dome, membrane, design, experimental study

The object of study is flexural reinforced concrete elements without transverse reinforcement under the action of shear forces. The calculation of reinforced concrete beams for shear is a complex problem, and its formulas are obtained by experimental or semi-empirical methods on the basis of various theoretical calculation models. In Russian standards, the calculations of reinforced concrete structures under the action of shear forces are performed based on the length of the most dangerous projection of the inclined section on the longitudinal axis of the element, and the formulas lack parameters that would take into account the influence of longitudinal reinforcement on the strength of inclined sections. The novelty of the present research is that the author, based on the theory of Prof. A.S. Zalesov, proposed a new approach to determine the shear strength of inclined sections of elements reinforced without stirrups. In the new approach, an analytical expression is obtained that takes into account the work of longitudinal regular reinforcement by introducing a longitudinal reinforcement coefficient. Examples of calculations performed according to the proposed methodology and SP 63.13330.2018 are given, where a series of experimentally tested specimens are taken for comparative calculation. The results of comparative calculations have shown the adequacy of the new approach to determine the strength of inclined sections of reinforced concrete elements reinforced without stirrups.

Keywords: reinforced concrete beam, beams without stirrups, inclined crack, shear stress, normal stress, strength, shear force

3D – printing is the quickly expending area of modern industry. In this review is carrying review of novel US patents on this topics.

Keywords: 3D - printing; application in civil & military engineering; application in industry and medicine

Bar structures are widespread in construction due to their economy, freedom of design shapes and sizes. As a result, automation of design and calculation of such structures is an urgent task. As part of the study, the task of developing a software module that generates a map of optimal cutting of rolled metal based on the results of calculations of rod structures has been implemented. The algorithm under consideration takes into account such features of the cutting optimization problem as taking into account the width of the blade, the possibility of using half the size of the rolled product, support for optimization of several sections, and welding of parts in case the length of the workpiece is exceeded. The software module is developed using JavaScript and C# languages. The ability to automatically generate cutting maps based on the results of optimization of rod structures increases the efficiency of designing building structures.

Keywords: Design in construction, bar structure, computing system, web development, design in construction, rod structure, computer system, web development, optimal cutting, rolled metal, cutting map

Nowadays, numerical methods are widely used to realise complex calculations.Verification of the correctness of the numerical calculation results is a relevant task. The validity of the results can be confirmed by determining the stress-strain state by various methods. This paper presents the results of the calculation of thin isotropic ring spherical shells of constant thickness with half-shell angle in the range of (90-170) degrees by two numerical methods. The results of solving the system of differential equations of the general moment theory of shells with the use of the computer mathematics system (Maple 2017) and the finite element method (FEM) are discussed. The given examples show that the calculation results with the use of the selected finite element KE-44 coincide with an accuracy of 10-15 % for shells with a half-shell angle of 120 degrees. When the angle is increased to 170 degrees, the difference in function values becomes significant. The paper gives some examples of calculation of ring spherical shells under the action of one and three annular loads. The variation of axial and radial displacements, of meridional bending moment for shells with the ratio of radius of the curvature to shell thickness 25, 50, 100, 200 is shown. Plots of meridional bending moment and moment isopole are given.

Keywords: elastic, spherical shell, numerical method, computer mathematics system, finite element method.

The article is devoted to the use of reinforced soils in the base of pavements of highways located in the I road-climatic zone. The features of the operating modes of reinforced foundation soils are considered, and their physical and mechanical characteristics with various combinations of mineral and polymer modifiers are determined. The authors analyze the advantages and disadvantages of using reinforced soils. The article also discusses the design and construction of roads using reinforced soils.

Keywords: highway, road pavement, foundation, soils, reinforced soils, modifiers

In accordance with the requirements of Federal Law No. 384-FZ, the safety and reliability of buildings and structures must be ensured. One of the ways to confirm the safety and reliability of building structures is to conduct field tests. The authors of this article have developed a method for full-scale testing of a reinforced concrete beam with a span of 14.52 m as part of a monolithic reinforced concrete ribbed floor. The procedure for testing the beam was drawn up with the development of measures to ensure safety during work, the adjustment of the beam testing method by loading was performed, the beam was tested by loading method with fixation of its deflections, followed by analysis of the test results. The test results showed that the developed method can be used as a full-scale test to confirm the safety and reliability of building structures, namely horizontal reinforced concrete structures.

Keywords: building structures, beam, destruction, safety, methodology, technical condition, field tests

Reinforced concrete structures must have sufficient reliability throughout their entire service life. In problems related to predicting service life based on an assessment of the technical condition, reliability can be considered as the probability of failure-free operation of structures, which consists in the ability to perform the required functions under given conditions during the design life. One of the methods for solving this kind of problem is statistical methods. The beam reliability calculation was carried out. It was further assumed that the beam was subject to degradation. As a result, a graph was constructed of the dependence of reliability on the depth of corrosion penetration into the compressed concrete zone. This graph also shows how the category of the technical condition of the beam changes over time.

Keywords: reinforced concrete structure, bendable structure, prediction, service life, reliability, technical condition, degradation impact

This article considers a new type of structures in the form of lightweight stainless steel floor slabs, gives an overview of application in construction practice, discusses the advantages and disadvantages. Based on the results of a series of structural analysis of several conditional models of buildings with different structural systems, the parameters of economic efficiency in the form of reduction of total metal intensity are determined. The area with increased efficiency of application of the considered plates in buildings is defined and the vector of necessary further research on the topic is outlined.

Keywords: B-Core slabs, multilayer floor slabs, stainless steel, metal cost reduction, efficient application area, structural building layouts

Numerical methods for calculating shells provide a wide range of solutions when varying various parameters. The object of this study is a mathematical model of thin isotropic elastic shells of revolution of constant thickness. The problem is solved from the position of moment theory.To determine the stress-strain-state of the shell, the solving system is obtained by transforming the basic systems of equations of rotational shells by moment theory and the variables separation. All SSS and load components are decomposed into Fourier series along the circumferentail coordinate. A programme in the Python programming language was written to verify the numerical solution by a computer mathematics system (CMS-Maple 17). Matplotlib library was used for plotting graphs. Examples of numerical calculation of ring spherical shells for the action of ring loads are given. The variants of action of one and two ring loads on shells with different conditions of support along the contours and different half shell angles are presented. The difference between the calculation results of the two methods for bending moment functions and displacement functions is tabulated. The highest value of the difference is 0.0015%. Plots of the variation of meridional bending moment under the action of two ring loads are presented. The variants of rigid pinching along the contours and hinged support are considered. Exsmples are given for shells with the ratio of radius of curvature to shell thickness equal o R/h = 25, 50, 150, 200. Considered of the half shell angles equal to 90, 100, 130 degrees.

Keywords: rotation shell, spherical, isotropic, elastic, computer mathematics system, Python programming language