The article estimates the intensity of rail failures on the sections of the Middle Siberian Railway (on the example of Kr and Km track distances). The analysis of rail failures depending on the passed tonnage, plan and profile parameters is carried out. Mathematical models of rail yield on I and II tracks depending on the missed tonnage, weighted average gradient, weighted average radius and curve share are considered.
   The influence of the passed tonnage on the rail output has been determined: on I track at tonnage increase from 100 to 1400 million tons the average value of rail outputs increases from 0 to 24 pcs./km, on II track – at tonnages from 100 to 700 pcs./km the average number of rail outputs increases from 0 to 1,8 pcs./km. However, during the whole operation period there is an accelerating intensity of rail failures growth from 0,7 to 4,3 pcs./km per 100 million tons depending on the tonnage interval.
   The influence of operational parameters of the plan and profile of the track of the Central Siberian mainline (the share of curves, average radius, average longitudinal slope) on rail failures has been determined. Dependence of rail failures on I track: on the share of curves – intensity of rail failures is 2,9 pcs/km on average for every 10 % of curve share. Influence of weighted average radius – when reducing the curve radius from 3 000 to 1 100 m on the example of tonnage level of 1 000 million tons, the rail output increases 3.5 times (from 4 to 14 pcs./km). Influence of weighted average gradient – when the gradient increases from 1,5 to 3 ‰ at the tonnage of 900 million tons, the rail yield increases 3 times (from 4 to 12 pcs./km).
   The correlation-regression analysis of rail yields from missed tonnage and parameters of track plan and profile has been carried out.

   We have established that the transportation (transportation) of dangerous goods by rail, road, river and sea, aviation, pipeline modes of transport poses a significant danger not only “by itself”; as a result of violations of the safety conditions of the transport process provided for by regulations. An analysis of a number of events at transport facilities in the period 2022–2023 revealed the possibility of using the transportation of dangerous goods as a factor in creating man-made emergencies. To solve large-scale geopolitical problems that contradict the interests of the Russian Federation. At the same time, cargoes that make up more than 50 % of the cargo flow on all types of transport carry a potential danger for critical disorganization of the transport process.
   The purpose of the work was to identify the features of a number of emergency situations that occurred in the regions of the world, to identify shortcomings and “bottlenecks” in the security system for the development of preventive security measures. On all types of transport, sustainable and safe transportation (transportation) is provided by critical transport facilities, or critical transport infrastructure facilities. The analysis showed the need for the phased development and implementation of additional, non-standard security measures that require an integrated approach. The actions of 2022 and 2023 were taken into account: the explosions of the Nord Stream pipeline in the Baltic Sea, the Crimean Bridge (Kerch Strait), the Tolyatti – Odessa ammonia pipeline (on the territory of the Kharkiv region of Ukraine) and the arson of a railway train in the Severo-Muisky tunnel (on the territory of the Republic of Buryatia of the Russian Federation). In all cases, dangerous goods were an additional hazard factor: methane, anhydrous ammonia (hazard class 2) and diesel fuel (hazard class 3). The study of fact gives us grounds to conclude about a trend or phenomenon as an object of research. Typological features make it possible to combine emergency situations as similar, "similar", within the framework of the study.
   The measures proposed for the development of a program for the prevention of terrorist threats using dangerous goods relate mostly to organizational and technical ones. Due to the closeness of relevant information, events are discussed without details that are important for the effectiveness of development.

   To ensure the reliable and safe operation of embankments on the Eastern section of the Baikal-Amur Mainline (BAM), including after modernization or repair, it is essential to eliminate or minimize cryogenic deformations of the structures. This goal is facilitated by improving the effectiveness of anti-deformation measures through an objective assessment of existing cryogenic issues, as well as the systematic analysis and forecasting of scenarios for further deformation development in the embankments of the studied section.
   Based on the historical aspects of the construction and operation of BAM, current cryogenic problems within this section have been summarized and formulated. Eight potential scenarios for the development of cryogenic deformations in embankments on the Eastern section of BAM have been outlined and categorized. For the probabilistic forecasting of deformation development scenarios and to determine priority directions for developing effective stabilization solutions for the “embankment – foundation” system, a survey of embankments on this section was conducted.
   The results of the survey on embankments across five intervals revealed specific characteristics of their current condition and deformation patterns. The embankments on the Eastern section of BAM not only reflect the consequences of past degradation of permafrost in their foundations, but they also possess a potential for deformation under continued operation, including post-modernization and repairs. These deformations may occur with particular characteristics and according to various scenarios.
   The probabilistic forecast of cryogenic deformation scenarios indicated that the most likely deformation scenario for embankment sections on this stretch is the subsidence of structures due to permafrost degradation in the foundation during thaw periods. The probability of other scenarios is relatively low (up to 15 %), though they do exist and must be considered in future modernization or repair activities. A significant portion of the forecasted scenarios (up to 30 %) combine multiple cryogenic issues simultaneously. Against this background, further research and theoretical justification of complex thermal stabilization solutions become increasingly relevant.

   The workload of the main railway directions and the need to manage railway wagon flows in conditions of limited throughput abilities of transport infrastructure accelerate the development and use of new information control information tools. As a result, there is a change in the transportation control paradigm, including through the delegation to intelligent systems of some of the functions traditionally performed by the dispatch apparatus. Thus, the number of control levels and the relationship between them changes. These issues initiate the development of new approaches and mathematical methods in transport and logistics research, in particular, in areas related to transport systems.
   The researches methodology of the organizational and technological sustainability of traffic control systems in railway transport is represented by “hard” and “soft” mathematical models, which are described by autonomous systems of ordinary linear differential equations. The transition from “hard” models to “soft” models is carried out by disaggregating the former. This is accomplished by introducing additional connections between the subjects of the considered two-level transportation process control system.
   The mathematical apparatus of the research is represented by the phase space (more precisely, the phase plane). The behavior of the trajectory corresponding to the unperturbed solution (equilibrium position) and the trajectories corresponding to the perturbed solutions of the system of differential equations under consideration is researched. Classical methods have shown that in this situation the system equilibrium point on the phase plane is the focus. Thus, it was established that for the «soft» model under consideration, the position of equilibrium is not only stable in Lyapunov, but also asymptotically stable. A phase portrait of a system of differential equations has been built, which describes the «soft» model. A comparative analysis of the geometric picture of the behavior of phase trajectories with graphical representations of the function, which expresses the daily number of wagons sent to the station, was performed.
   These results will be in demand when developing intellectualized control systems for train and wagon flows, since they are a mathematical justification for the stability of the functioning of these systems.

   Acoustic pollution of residential areas from railway transport facilities is an urgent scientific and technical problem. As part of the search for acceptable solutions to this problem, the features of sound generation in the source and the specifics of noise propagation in the territory are considered in order to determine all possible ways to protect the population from noise. The railway station, both by its main purpose and the nature of the work performed, is a two-way marshalling yard with a sequential arrangement of parks and parallel arrangement of systems, and is classified as extracurricular in terms of the volume of work. There are two automated high-capacity slides at the station for disbanding and forming trains. The process of disbanding rolling stock is the main cause of significant acoustic pollution of the adjacent residential area.
   The speed and distance of sound transmission depends on the medium in which it is distributed. For example, at an air temperature of 20 °C, normal atmospheric pressure (760 mmHg) and normal relative humidity (from 40– 60%), the average speed of sound is 343 m/s. The air environment has parameters that significantly affect the trajectory, speed characteristics and range of the sound wave. The effect is exerted by air humidity, the direction and speed of air masses, air temperature and other factors. The physical state of the atmosphere is incorporated into the calculated attenuation formula in the form of coefficients that integrally take into account the combination of temperature, humidity, and air velocity. The attenuation process also largely depends on the terrain, the existing obstacles in the path of the sound wave.
   These terrain features and the climatic state of the environment largely determine the choice and design of acoustic pollution protection systems. By calculating, by entering the insulating capacity of the protective equipment into the formula, we determine the presence or absence of exceeding the maximum permissible sound pressure level at a given point (residential building).
   In the article, we will consider the features of the propagation and attenuation of noise in the atmosphere in the territory adjacent to the station under various weather conditions and protection options.

   The article focuses on the presentation of graphical models for managing organisational and technological processes of maintenance and repair of line-dispersed facilities in the form of information flow operograms as tools for assessing the reliability of organisational and technological processes within the framework of the activities of the infrastructure management center of the Central Infrastructure Directorate of Russian Railways. At this stage of research, the main attention is focused on the methodology for assessing the efficiency of infrastructure complex management that makes it possible to reduce losses from reducing the influence of the human factor.
   The purpose of this study was the graphical modeling of information processes of maintenance and repair of railroad infrastructure elements. The structure of graphical models in the article is presented in the form of a graph with a set of vertices and a set of arcs symbolizing performers and information links between them. Information flows circulating in the system are assumed to obey Poisson's law, and the time of their processing is assumed to obey the exponential law. The algorithm of modeling of information processes consisting of eight positions is offered: justification of the graph of information interrelations of operations on management of revealed failures of technical means of railway track; description of the graph by the system of differential equations; modeling of information flows; analysis of probabilities of fulfillment of operations and cycle of management of revealed failures; calculation of the coefficient of loading of participants of structural divisions; change of their number and continuation of modeling of information processes. The procedure of formation of the information flow of detecting failures by a track measuring car and the sequence of decision-making on their elimination is outlined. The proposed approach makes it possible to apply the method of optimizing the duration of restoration work and assess the organizational reliability of technological processes of current maintenance and repair of railroad infrastructure facilities.

   The safety of train dissolution on hump yards plays an important role in the transportation process of railway transport and must certainly be ensured. One of the important conditions for the safe operation of hump yards is the collision of wagons in the sorting yard at a permissible speed.
   When calculating the hump yards, the slopes of the tracks of the summit yard are assumed to be 0.6 ‰ for the entire length except for the last 100 m. Based on previous studies, it was found that the specific resistance to the movement of the cuts on the hump yard is significantly less than is accepted in regulatory documents. In a number of works it's proposed to revise the normative values of specific resistance to cuts movement. The article deals with the question of how this fact affects the movement of cuts in the sorting yard.
   It was found that the slopes of the sorting yard tracks 0.6 ‰ can be accelerating for a number of cuts. This leads to the fact that there is a possibility of exceeding the collision speed of the cuts with wagons standing on the tracks of the yard, compared with the permissible values. This can happen even if the cuts are released from the yard braking position at a minimum speed.
   To exclude such cases, it is proposed to design the sorting yard tracks on a horizontal platform. This will avoid exceeding the permissible collision speed for good runners. For the rest of the cuts, there will be no significant changes in the speed limit in the sorting yard. As an alternative option it’s proposed to design only the first 100 m of the sorting yard tracks on a gradient of 0.6 ‰.

   The article considers the importance and relevance of the development of heavy and long-distance traffic on the railway network. As world experience shows, the development of heavy and long-distance traffic is an urgent and in-demand measure for the active introduction of innovations in railway transport. Heavy lifting is used in Australia, Brazil, Canada, China, USA, Sweden, Norway, South Africa. The length of the lines where such trains run ranges from 180-200 to 1100-1500 kilometres. In most cases, these are specialized highways. The trains include up to 340 wagons.
   Back in 2015, Russian Railways developed a program for the development of heavy-duty train traffic. On the network of Russian Railways, the number of trains with an increased mass is constantly increasing. Undoubtedly, the development of heavy and long-component traffic has a great positive impact on the activities of the railway industry: the use of innovative wagons with increased axial load, acceleration of the turnover of wagons, increase in throughput and processing capacity of railway facilities, etc. However, like any solution, there are also a number of tasks that need to be solved when considering the organization of heavy traffic on the road network. In particular, the development of heavy traffic requires a systematic approach to the problems of interaction between the crew and the track, wheel and rail, the longitudinal dynamics of trains, overloads in the power supply system, the reliability of providing locomotives during departure, taking into account the length of station tracks and industrial enterprises, and a number of other issues.
   The article considers the possibility of forming trains weighing 7,100 with a mass load. Calculations of the sufficiency of the length of the tracks of station P, as well as station Z, for the formation of a long-composite train are performed. It has been established that the most appropriate option is to form a train on the tracks of the Z station. Since due to the formation of high-mass trains on two tracks at station P, downtime will increase, there are also shortcomings in the technology of working with heavy trains at this station. The possibility of sending a train weighing 7,100 tons under the condition of starting from the place was checked. There are recommendations on the design of the contact network on the P-Z stage, as well as the organization of a car maintenance point at the Z station. An economic assessment of the feasibility of forming a long-component train has been carried out.

Fatigue is one of the consequences of the structural degradation of cement-containing composites under non-stationary external influences of various origins. One of the proven ways to increase their fatigue resistance is to modify the structure of fine fibers of materials of high strength and extensibility and physically compatible with the cement matrix. The article analyzes statistically representative experimental data on changes in the damping potential of conventional and fibropolypropylene reinforced concrete under a few cyclic influences, the level of which simulates stress fluctuations in structures under background seismic influences. The results of dynamic tests of prismatic samples with different levels of maximum stresses in the range R^o _crc…R^ν _crc and a zeroasymmetry coefficient are presented. The response of structures is considered as an oscillatory process, the kinetics of which is estimated by the change in the fracture energy under standardized conditions of monotonic loading. The tests were carried out on the Instron 5989 universal test complex in a rigid mode of cyclic and subsequent monotonic compression with a constant deformation rate of 0.04 mm/s up to destruction. An original technique of multifactorial automated control of parameters, time of phased resistance, energy of destruction and other parameters at each cycle of loading and unloading is used. A comparative assessment of the energy potential of concrete and fiber concrete and the kinetics of energy indicators at the stages of cyclic loading is given. The high sensitivity of composites to cyclic effects of the accepted intensity has been established, confirmed by a noticeable decrease in the energy of post-cyclic compression (destruction). The possibility and technical and economic feasibility of strengthening the fatigue resistance of reinforced concrete elements through the introduction of finely dispersed polypropylene fibers has been confirmed.

   The main modern intermediate rail fasteners on the railways of Russian Railways are fasteners with elastic bar terminals. The design of these fasteners continues to be constantly developed by developers, including the emphasis on the design of the elastic bar terminals themselves. One of the main disadvantages of B-shaped elastic terminals is the inefficient distribution of the mounting force – about half of the force applied to the bolt (fastener) is directed at pressing the sole of the rail.
   A terminal in the form of a torsion spring (or a coil terminal) is considered as a promising design of an elastic bar terminal for intermediate rail fasteners, the main advantage of which is a more successful clamping force distribution scheme.
   The article presents the results of multivariate modeling of the geometric parameters of the winding terminals (42 pieces) with an analysis of their stress-strain state. The calculations were carried out using the SolidWorks and Ansys Workbanch software and computing systems.
   As a result of calculations of multivariate models the stress-strain state of the coil terminal was analyzed and the degrees of influence of the intervals of variation of the geometric parameters of the terminal were determined: terminal coil pitch (17–30 mm); terminal rod diameter (12–20 mm); number of terminal coils (1.4–3.4); terminal coil diameter (50–70 mm).
   Based on the geometry of the rail, the relative location of the proposed elements of the fastening unit, ensuring an optimal stress-strain state and the lowest possible material consumption of the terminal, the most optimal design parameters of elastic terminals in the form of a torsion spring are: the diameter of the coil is 50 mm, the number of coils of the semi-terminal is 2.4, the diameter of the rod is 16 mm, the pitch of the coil is 17 mm.

This work shows that if, when recording holograms, the recording medium is located at a considerable distance from the surface of the working raster, then the recorded optical information is largely determined by the angles of inclination of the surface being studied. When deriving the resolving equation, the normal component of the displacement vector was expanded into a Taylor series in the vicinity of a point on the surface under study, forming a reference beam. Only the linear term of the series was retained in the equation. It is also taken into account that for plates of medium thickness, the displacements tangent to the plate are proportional to the angle of inclination. The article describes the technique of applying a working raster to the surface under study using a replica raster. The results of a study of the bending of a thin, round, rigidly clamped plate are presented. Hard pinching was modeled by a sharp change in the thickness of the plate. The plate was made on a lathe. The average cylindrical stiffness was determined experimentally, based on the maximum deflection of the plate determined using holographic interferometry. During the tests, a spirit-exposure hologram was recorded in colliding beams at different levels of hydrostatic pressure on the plate. The patterns of interference fringes observed in light passing through the hologram in +1 and –1 diffraction orders were recorded. The coordinates of the center of the interference fringes in the paintings were determined manually. Information obtained in the +1 and –1 orders was approximated by power polynomials using the Excel spreadsheet program. The half-difference of these polynomials was taken as the equation for the inclination angles of the midline of the plate. A good agreement between the experimental data processed using new resolving equations and the theoretical solution was obtained.

   The article provides the analysis of the physical and mechanical characteristics of the roadbed soils in the areas of reinforced concrete culverts based on surveys conducted on one of the most important highways for the Siberian region. The physical and mechanical characteristics of the roadbed soils in the areas of reinforced concrete culverts are determined and combined into engineering and geological elements, graphs of the dependence of the soil compaction coefficient on the depth of the pit and the dynamic resistance of the soils are given, the values of the physical and mechanical characteristics of soils and the condition of the pavement in the areas of reinforced concrete culverts are compared.
   It was found that in the areas of reinforced concrete culverts, when approaching the pipe, the number of defects and deformations of the pavement increases. The physical and mechanical characteristics of the roadbed soils located near the reinforced concrete culvert and at a distance of 30 m from the pipe axis differ. When moving away from the axis of the reinforced concrete culvert, the physical and mechanical characteristics of the soils improve. The conducted visual, field, laboratory studies and dynamic sensing confirm this conclusion. So, in the sinuses of culverts, the dynamic resistance of the roadbed soil is set at 3 MPa, and at a distance of 30 m from the axis of the reinforced concrete culvert 4 MPa.
   The research area under consideration is relevant, since timely, accurate and rapid assessment of the physical and mechanical characteristics of the roadbed soils is necessary to reduce road accidents and rational maintenance and repair.

Mobile laser scanning has found wide application on railways and highways. Control of building approach dimensions is one of the areas of laser scanning application on railways. Determining dimensions using mobile laser scanning increases the productivity of field work. At the same time, processing the obtained data and determining the dimensions is a labor-intensive process. In some cases, when performing work on a railway track, the measurement and assessment of dimensions must be performed in real time. To determine the building approach dimensions in real time, a building approach dimensions control system (BAC) has been developed based on lidar, machine vision and computer learning. The BAC operation is based on measuring the coordinates of the surrounding space in a given sector and selectively selecting from the point cloud the coordinates of railway infrastructure objects that are specified in the digital project and entered into the database. Computer learning allows you to create a mathematical model of an object and recognize an image during in-kind measurements, which makes it possible to determine the dimensions in real time. One pass of the system along a section of the track ensures the definition of the track geometry and the clearances of approaching structures. The results of the SKG tests showed a high degree of the system's resistance to external factors, operational stability and provision of the required measurement accuracy. The system for monitoring the clearances of approaching structures on railways is designed for the acceptance into operation of completed railway repairs, assessment of oversized areas, execution of executive surveys and operational control during repairs.