To assess the quality of operational work of railways, a number of indicators are used, one of which is the section speed of freight trains. The fulfillment of other indicators of operational work depends on this indicator. In turn, this indicator is influenced by a large number of factors, which are difficult to take into account using generally accepted analytical dependencies. This prevents the objective establishment of a planned task for section speed, as well as the assessment of losses allowed in implementation.
   Therefore, a method was proposed that allows you to estimate the losses of section speed, based on taking into account the whole variety of factors that affect it. The method is based on the presence of a statistical relationship between the section speed and the working fleet of freight cars. The size of the working fleet, in turn, is formed under the influence of all factors leading to a slowdown in the passage of car flows.
   Using the tools of probability theory and mathematical statistics, the article examines the influence of the working fleet of freight cars at individual territorial administrations of the railway on the section speed of freight trains on the railway. The purpose of this study was to increase the accuracy of determining the losses of section speed of freight trains in conditions of difficulties in passing car flows.
   In the course of the study, carried out on the statistical data of the Gorky Railway for 2022–2023, it was found that if the change in the working fleet of freight cars on the railway explained 85% of the variability of the section speed on the railway, then when switching to the working fleet of freight cars of individual territorial administrations of the railway, the degree of explanation of the variability of the final indicator increased to 90 %. Based on the results of the study, a regression equation was compiled to determine the losses of section speed, which made it possible to reduce the forecast error by 2,5 times.

   The paper studies acoustic pollution of residential areas from the sorting slide of the railway station I in order to reduce the negative impact of noise on the population. 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.
   The process of disbanding rolling stock, and especially the sound generation at the moment of passing the wheel rim through the braking position, is the main cause of significant acoustic pollution of the adjacent residential area. The speed and distance of sound transmission depends on many factors – the period of the year, the time of day, the temperature and humidity of the air, the presence of a reservoir nearby, the presence of barriers reflecting the acoustic wave, the architectural and planning organization of the territory, and the terrain.
   Previously, we considered the features of sound wave propagation in various atmospheric conditions. In this article, we will consider how the terrain and the architectural plan of the territory affect the intensity of acoustic pollution of the residential area.
   The height of location of the noise source and protection facilities (residential buildings) largely determine the configuration and design of protective screens – artificial barriers to the propagation of a sound wave. The main task is to construct isolines that visually display the zones of compliance (non-compliance) with the maximum permissible noise levels directly on the terrain map. To do this, the ERA-noise software module was used, which allows you to build map diagrams based on the measurements. They are the basis for designing protective screens on the ground: the correct location of the screen, the size, height and configuration of the screen, construction materials. Additional attenuation of the sound wave can be provided by increasing the security of the object itself – noise-absorbing cladding of the front side of buildings, noise-proof blinds and other means of protection.
   The results of the work can be used to create comprehensive noise protection system projects, which may include protection at the source of occurrence and along the path of propagation, as well as improving the security of residential areas (residential and public buildings). The choice of the necessary protection combination may directly depend on the terrain and architectural and planning organization of the area.

   For the successful organization of the transportation process, it is necessary to ensure the rational use of traction resources. The size of the required fleet of freight locomotives is determined during the development of technical standards for the planned month on an average daily basis. Due to the existing restructuring of logistics and uneven transportation, the use of planned technical standards is difficult. Because even a slight increase in freight traffic can lead to an excess or shortage of locomotive fleet on the sites. The use of an objective operational management methodology, as well as its competent implementation, is the beginning of high-quality freight and train work with minimal operating costs. Therefore, it is extremely important to identify possible options for operational planning of traction resources, the implementation of which leads to efficient operation of locomotives, as well as timely installation of traction rolling stock for maintenance, repairs and equipment. The authors' analysis of statistical data over a long period has shown that the existing methodology for calculating operational fleet planning indicators does not take into account individual factors affecting the determination of the actual size of the required locomotive fleet.
   The article considers real examples of the organization of the corporate locomotive fleet within the West Siberian Railway. The location of the loading station in Kuzbass, and therefore the distance travelled by empty and then loaded trains, is not taken into account when planning transportation, as train flows do not always follow the shortest route (depending on the operational situation).
   Attention should also be paid to so - called delayed trains. The most common reasons why trains are delayed at stations of the West Siberian Railway are downtime of trains at intermediate stations for more than 6 hours, non-acceptance of trains by the consignees, as well as the absence of a locomotive carrier. A large accumulation of such trains at stations can lead to difficulties in passing trains and additional work of the locomotive fleet.
   The purpose of the study is to determine the dependence of the volume of the required locomotive fleet on changes in the organization of its use in freight traffic, taking into account additional factors.
   It was found that during the operational planning of train operations in freight traffic using automated programs of the PROGRESS system, based on calculations of locomotive turnover using the analytical method used everywhere, additional time components were not taken into account, taking into account the current operational situation at the landfill. It is proposed to supplement the methodology for determining the turnover of locomotives with elements that take into account the real situation and take into account the additional work of the locomotive fleet.

   Ensuring the stability of the track geometry is an integral part of the current track maintenance. Track straightening accounts for a third of all labour costs at the track distance, the state of the track geometry affects the safety level of driving and determines the efficiency assessment of the structural subdivision. Track straightening by level, plan and profile is carried out both manually by a team of track installers, and due to the operation of the machine complex as part of the planned preventive track straightening. In the context of the workers shortage, a natural question arises about reducing labour costs due to the mechanization of the main technological processes to maintain the track.
   This paper presents the results of a study on the analysis of the dependence between periodicity of preventive maintenance and the state of track geometry, including taking into account the required labour costs for manual track straightening. Sections of the Central Siberian passage with the value of the passed tonnage from 300 to 1200 million tons with different frequency of machine straightening were selected for the analysis. To process the initial data for the analysis, the Python programming language was used, which made it possible to automate the process of calculating the required labour costs for manual straightening of the path. The article shows the dependence of labour costs for track maintenance depending on the amount of missed tonnage, taking into account the periodicity of planned preventive straightening. Degree of track straightening efficiency is determined by machine complex depending on value of passed tonnage and number of straightening. It was noted that in the conditions of a shortage of working personnel for the purpose of planned and preventive straightening, it is rational to use an additional criterion – the amount of labour costs for straightening the track, since this parameter directly reflects the labour intensity of maintaining the rail track on the linear section.

The variability of natural and man-made factors and the complexity of reinforced concrete calculations make the problem of estimating the service life of reinforced concrete bridges spans multifaceted and complex. Along with this, the construction of the Moscow – St. Petersburg high-speed railway has started in Russia, which makes the problem of the durability of reinforced concrete bridge spans even more actual. Fulfilling the requirement of SP 453.1325800 to ensure a service life of 100 years is currently difficult for the designer to achieve, just as there are no ways to verify compliance with this requirement. Reinforced concrete bridges under HSR conditions will be subject to significant dynamic impacts, which, together with an aggressive environment, can significantly reduce the service life of the structure. This article discusses corrosion-fatigue durability as one of the aspects of the method for predicting the service life of a bridge, taking into account the dynamic load. This type of degradation of reinforced concrete is caused by the combined action of pitting corrosion of reinforcement and cyclic loading, which leads to the initiation and growth of a fatigue crack in the reinforcing bar.Methods of calculating the time of crack growth in reinforcement up to the critical value are analysed, Paris law is highlighted as widely used in fracture mechanics. The problem of applying Paris law lies in the empirically determined material coefficients. Literature analysis shown that coefficients can depend not only from type of material but from specific alloy as well. The task was set to conduct an experiment to determine the coefficients of Paris's law for reinforcing steel grade 25G2S, which is widely used in bridge superstructure. The test was carried out using a vibrating machine and reinforcement samples with an initial stress concentrator. Based on the results of the experiment, the coefficients of the Paris equation were determined for reinforcing steel 25G2S, which will make it possible to use them in the methodology for predicting the development of fatigue cracks.

   The essence of dowel fastening for ensuring the stability of the walls of deep pits, slopes of ravines or steep slopes of the earth's surface is considered. To implement this progressive type of support, especially in cramped construction conditions, during “spot development” in urban conditions, the possibility of using an annular pneumatic impact machine of the PUM type is being considered. Based on an analysis of the design features, the operating cycle of these machines and production tests, reserves for increasing operational productivity during the operation of the impact system as a whole were identified.
   Calculations have shown that even with insignificant mobility of the rod element driven into the ground, most of the energy of the first wave of the shock impulse (more than 75 %) is not spent on performing useful work. In addition, quite a lot of time is lost (up to 20 % of the driving cycle time) on the perception of the reactive recoil force, i. e. there is manually pressing the machine towards the face at the beginning of the insertion of the rod. There is additional time lost in replacing the wedge cams as they wear out.
   The feasibility of the development and implementation of a feeder is substantiated – a device for creating an external pressing force on the body of the impact machine, which allows you to select all the gaps that arise in the impact system and create optimal conditions for the operation of the clamping mechanism. The design of a quick-dismounting wedge clamping mechanism has been proposed, which allows replacing cams within 5...7 minutes.

   The concrete of the anchorage zone of a post-tensioned reinforced concrete element is in a complex stress-strain state. The concrete area behind the anchor experiences significant local tensile stresses – bursting stresses transverse to the longitudinal prestressing force.
   In most cases, the anchorage zones in the main girders of superstructures are located near the support sections. In this way, dense reinforcement for shear force and torsion can be found in the analysis area. However, in addition to the standard transverse reinforcement, extra transverse reinforcement must be considered to provide strength for local bursting stresses.
   Actual national standards require the designer to take into account the stress-strain state during the analysis the reinforcement of anchorage zones, but do not provide a design method.
   This paper presents a method of design the transverse reinforcement to provide strength for bursting stresses for a post-tensioned main girder of an overpass with a large set of anchors AKS-19 (STS, Moscow). Two design cases are considered: the first one with anchorage zone located above the bearing pad (the bearing influence on the stress-strain state of the anchorage zone concrete is taken into account); the second one with anchorage zone located on the border of the casting sections (the stress-strain state is determined directly by post-tensioning). A description of the applied analysis models is made, specifying the preconditions and assumptions in the analysis. The results of bursting force calculations and design of additional transverse reinforcement are given.

   The article presents the results of the research on the development and implementation of the system of engineering and geocryological monitoring of the operating embankments of linear transport structures in the conditions of climate change on the example of a section of the earth bed in the Yamalo-Nenets Autonomous Okrug (YNAO). The stages of substantiation of the system of engineering-geocryological monitoring of the used embankments of linear transport structures in the considered conditions are proposed.
   On the basis of the results of visual-instrumental and geotechnical investigations, a scheme of deformation characteristics of the section of the operated embankment typical for the considered conditions was formed, and a transverse geocryological profile was constructed. A universal system of zoning of the exploited embankment, the right of way and the adjacent territory, taking into account the influence of cryogenic processes and factors, was developed and applied to process the obtained survey results.
   On the basis of the conducted researches the peculiarities of the geocryological condition of the exploited embankment site typical for the YNAO conditions were formulated, which are necessary for the justification of the engineering-geocryological monitoring system. The scheme of installation of the engineering-geocryological monitoring system was substantiated, a complex of measuring devices for objective control of thermal and deformed state of the geotechnical system embankment-base on the site of the operated embankment typical for YNAO conditions was developed and manufactured. The installation of the engineering geotechnical monitoring system was carried out, as well as the zero and first observation cycles, which confirmed the efficiency of the system and the absence of the need to adjust its parameters.

The paper deals with the problem of ultimate equilibrium of a collapse vault formed over underground structures of curvilinear outline. A detailed critical analysis of the normative methodology is given. It is shown that the normative methodology has a number of drawbacks related to the impossibility to determine the strength coefficient other than by the descriptive scale of M. M. Protodyakonov or by formula referring to the same scale. The following is a review of some solutions to the problem of the collapse vaulting in rocky soils, namely: the problem of the vaulting of the limit equilibrium (collapse) over a mine excavation, considered by W. Ritter (1879). Ritter (1879); the problem of J. O. Stakhnev (2023), in which Ritter's solution was developed, first of all, in terms of taking into account not only normal, but also tangential stresses acting along the contour of the collapse vault; the solution of the problem of the limit equilibrium of the collapse vault in rocky soils, obtained according to the Ritter – Stakhnev scheme, but with the use of methods of calculus of variations, obtained earlier by the authors, is also analysed. This solution was obtained in closed form. A distinctive feature of the obtained results is the rejection of the notion of strength coefficient in favor of standard strength characteristics of rocky soils. Further in the theoretical part of the paper the solution of the problem of collapse vaulting over curvilinear underground structures (over calotte) as a problem of variation calculus is given. The paper shows that the presence of the calotte does not affect the outline of the collapse vault, but reduces the load from the rock pressure on the underground structures. The results section of the study describes a practical method for calculating the ground pressure on curvilinear underground structures.

   The article presents the results of research on the bearing capacity, crack resistance and endurance of reinforced concrete sleepers with rod reinforcement, which are manufactured using the Italian automated OLMI technology. Two types of sleepers are calculated SH3-D 4×10 and SH3-DPG 4×10. SH3-DPG 4×10 sleepers differ from SH3-D 4×10 sleepers by additional indirect reinforcement in the end section in the form of spirals at the ends of the reinforcement and end holes minted with concrete mortar. At the same time, the concrete compressive strength class for SH3-D 4×10 sleepers is assumed to be at least B55, and for SH3-DPG 4×10 sleepers it is assumed to be at least B60.
   The load-bearing capacity calculation is performed according to the method of calculating bent elements of any shape of cross-sections, directions of action of the external moment and any reinforcement in the general case of calculating normal sections of bent elements. The specifics of the operation of iron-concrete sleepers under load require mandatory calculation of crack resistance and endurance, since the impact of multiple repetitive loads on the sleeper causes a significant stress drop in concrete or in stretched reinforcement with a large number of cycles during the operating period.
   Based on the results of the calculations, it was found that an increase in the concrete class in compressive strength from B55 to B60 has practically no effect on crack resistance and bearing capacity, which means it will not lead to a decrease in the defects of reinforced concrete sleepers with core reinforcement on load-stressed sections of the Central Siberian Railway.

   During the construction of transportation facilities in the cryolithozone, the temperature regime of permafrost soils is radically disturbed. During the operation of the Baikal-Amur Mainline for several decades, the so-called thawing bowls were formed at the base of the subgraid in some sections in the areas of high-temperature frozen soils. These are zones of thawed perennially frozen ground located directly under railway embankments, even when the first principle of construction is used. This applies mainly to embankments with drainage soils. In this case, the formation of such bowls is primarily promoted by infiltration of atmospheric precipitation into the body of the subgrade. It is very problematic to estimate the effect of precipitation on the warming effect of the subgrade because of the chaotic nature of filtration processes occurring in the body of the subgrade.
   In this paper an attempt is made to use a non-traditional approach to solving this problem, namely, it is proposed to introduce a correction to the summer values of the coefficient of thermal conductivity, taking into account the heat exchange of filtered warm atmospheric water with solid particles of the draining soil. To determine the correction to the thermal conductivity coefficient, an empirical approach was used. It consists in correcting the heat conductivity coefficient in the process of numerical calculations, focusing on the real depth of the upper boundary of permafrost under the embankment, obtained during geotechnical surveys. The heat conductivity coefficient thus selected can be used for further calculations under similar conditions.
   Using the proposed approach, an effective embankment design from draining soils was justified. It is also shown that the use of such a technique to prevent degradation of the embankment base soils is effective in the construction of the earth bed for the second tracks in the cryolithozone.

   The article is devoted to the issues of forecasting the durability and reliability of reinforced concrete superstructures of bridge structures. It is assumed that the durability and reliability of superstructures depend on the condition of the main beams, the performance of which is determined by the condition of concrete and reinforcement. The purpose of the study is to develop a methodological approach to the study of reliability indicators of superstructure beams using simulation modeling methods.
   To study durability and reliability, to identify patterns of influence of stochastic parameters of traffic flow, maintenance technologies and operating conditions on the condition of bridge structures, simulation algorithms and procedures for ‘process-event’ generation of destructive factors are proposed. The reliability and durability of superstructure beams are determined by changes in the cross-sectional area of the reinforcement, considering the combined effect on concrete and reinforcement of the composition and intensity of traffic, technological processes of construction and maintenance of bridge structures, physical and mechanical characteristics of the materials used and the effects of aggressive media.
   The development of a simulation model and the conduct of a series of simulation experiments made it possible to substantiate correlation, regression and analytical dependences reflecting the statistical characteristics of the area of corrosion damage to reinforcement and the operating time for failure of superstructure beams in a wide range of effects of loads, deicing materials, and chemically active gases.
   The proposed methodological approach allows design and road maintenance organizations to predict the inter-repair service life of spans of reinforced concrete bridges, to develop measures to increase their durability and reliability, which helps reduce costs not only for the operation of bridge structures, but also the timely elimination of the consequences of premature destruction.

   In recent decades, building information modeling have become an integral part of the construction industry. These new technologies provide powerful tools for project management, modeling, resource optimization, and improving the accuracy and quality of design. Despite the obvious advantages, the implementation of new technologies for managing construction processes faces a number of challenges in our country, particularly the lack of libraries of standard elements for bridge structures.
   The article examines the need to integrate standardized design practices with building information modeling. An analysis of the designs of existing reinforced concrete superstructures and intermediate supports of road bridge structures is presented. A set of attribute information and parameters for building information models required at the stage of developing project documentation for the repair and operation of structures has been established. The most common standard designs of reinforced concrete superstructures and supports have been identified, and for selected standard sizes of structures, detailed digital information models have been developed, including working and structural reinforcement of elements. These models have been exported to an open data format, which enhances their compatibility with various software products and promotes widespread practical adoption.
   The results of this work can serve as a foundation for creating a comprehensive catalog of existing reinforced concrete superstructures and supports for road bridges in the coming years. The implementation of such solutions will not only reduce time and resource costs but also ensure the transition of domestic infrastructure to a qualitatively new level of digitalization.