Introduction. The need of transitioning from traditional maintenance methods to operational monitoring systems that enable real-time defect detection is proved. The task of improving the reliability of crane drives through early detection of mechanical damage based on analysis of asynchronous motor stator currents is set. The importance of studying the dynamics of transient processes for the development of effective diagnostic algorithms is shown.
Materials and methods. A mathematical model of electromechanical processes in the α-β coordinate system has been developed, taking into account the mutual influence of the resistance torque and the electromagnetic characteristics of the motor. The model is parameterized based on data from industrial crane drives. Numerical simulation for the study of transient processes during sudden load changes was performed in the Wolfram Mathematica environment. Equations of electrical balance, magnetic fluxes, and mechanical motion adapted for the operating conditions of crane equipment were used.
Results. It has been found that changes in the mechanical operating conditions of the drive are manifested in specific changes in the stator current parameters, such as an increase in the oscillation period when the load is released. It has been shown that the stator current oscillation period decreases by 10% when the load is applied and increases by 15% after it is removed.
Discussion and conclusion. The results obtained show the possibilities and limitations for using the stator current as an informative parameter to study the operation of the crane mechanism for its diagnostics in real time.

Introduction. The article is devoted to modeling the process of interaction between a vibratory roller and deformable soil during compaction of technological layers of a highway. The relevance of the study is determined by the need to improve the quality and durability of the earth bed of roads and railroads, which directly depends on the efficiency of soil compaction.
Methods and Materials. The research using the method of mathematical modeling of the oscillating system “roller vibration roller - deformable medium” is presented. The system includes interacting elements possessing rigid and viscous properties. These properties correspond to the rheological characteristics of the working body of the roller and the medium deformed by it. The model is based on the system of second-order differential equations describing the interaction between the masses of the vibratory roller and the ground medium taking into account their elastic- plastic and viscous properties.
Results. For the first time relations between viscous friction coefficient and stiffness of deformed soil on the influence of external deforming force have been presented. On the basis of these data the system of differential equations of motion of oscillating masses has been considered, which allows determining average values of vibration accelerations in the volume of compacted soil. A functional dependence specifying the mass of actively deformed soil depending on vibration parameters, geometric characteristics of the roller and soil type has been proposed for the first time.
Discussion and conclusion. The obtained results can be used to substantiate the rational frequency of vibration exciter vibrations and other mode parameters of road rollers, which helps to improve the efficiency of transportation construction. The improved mathematical model of interaction between the roller’s vibrating roller blade and deformed soil makes it possible to determine the values of vibration accelerations of particles of deformed soil. The results of the study can be used to improve the efficiency of road-building machinery, in particular, in the design of road rollers.

Introduction. Ensuring the operational safety of cargo lifting cranes, especially at nuclear power facilities when transporting hazardous loads such as spent fuel assemblies, requires high precision in the calculation of loadbearing structures. Existing modeling approaches do not always consider the influence of the detailing of removable load-handling attachments (RLHAs) on the overall stress-strain state of the crane. The objective of this study is to assess the influence of the finite element model’s level of detail for a traverse type RLHA on a flexible suspension on the convergence and accuracy of the static calculation results for an overhead crane.
Materials and Methods. The study was conducted using the case of transporting TUK-13 containers with an overhead crane equipped with a traverse on a flexible suspension. Three variants of the crane’s computational static model (CSM) were developed and analyzed, varying in the way the RLHA was modeled: 1) representation of the load from the RLHA and cargo as lumped masses (weight); 2) use of a detailed model of the RLHA with cargo, featuring rigid element joints; 3) application of a detailed model of the RLHA with cargo, taking into account hinged joints. For each of the three models, a static analysis was performed using three different methods: linear static analysis, static analysis considering the P-Δ effect, and static analysis paying attention to both the P-Δ effect and large displacements.
Conclusions. The comparative analysis showed that accounting for flexible suspension elements and hinged joints in the RLHA design requires consideration of the P-Δ effect and large displacements to adequately describe the deformed state of the “crane-RLHA-cargo” system. Linear methods and simplified RLHA models can lead to significant inaccuracies. The choice of the detailing level of RLHA and the calculation method significantly affects the reliability of the obtained results.
Research Scope and Future Use. The results are applicable to the static analysis of overhead cranes with flexible suspensions and complex RLHAs. Further research could be extended to dynamic operating modes and other types of RLHAs.
Practical Significance. The obtained information is important for engineering practice in the design and verification of overhead cranes’ calculation, enabling the selection of a rational balance between the model’s level of detail and the computing method to ensure the required accuracy and safety.
Originality and Value. The novelty of this work lies in the systematic comparison of the influence of both the RLHA model’s level of detail (from umped masses to a detailed model with hinged joints) and various static analysis methods on the results for a crane with a flexible suspension. The results will be useful for design engineers, stressstrain analysts, and safety specialists working with lifting equipment in critical industries.

Introduction. The paper considers methods for determining the specific surface area of porous stone materials formed during milling of asphalt concrete pavements with road cutters. The specific surface area is a key parameter affecting the adhesive properties, compactness and durability of secondary asphalt concrete mixtures.
Materials and methods. The paper presents a method for determining the specific surface area of nonporous stone materials. The method is based on three-dimensional scanning followed by the construction of a point cloud. The resulting polygonal models of individual particles are used to calculate the area and volume.
Results. As a result, the values of the surface area and volume of particles of stone material have been obtained. The stone material was previously partitioned into fractions according to the particle size by sieving it through sieves with variable cross-section sizes. In addition, a method for determining the specific surface area of non-porous stone materials has been proposed, which allows for increased accuracy.
Discussion and conclusion. The method for determining the specific surface area of non-porous stone materials described in this paper can be used not only in the road and construction industries, but also in the metallurgical, chemical, and mining industries. The key result of the work is that the method can be used to determine, for example, the bitumen content or consumption of bitumen emulsion in the preparation of asphalt and cement mixtures during recycling. Additionally, the method provides assessment of the energy expended both during the milling and the grinding of other solid materials.

Introduction. The article is devoted to the analysis of the influence of various factors characterizing the element «Automobile» within the framework of the «Driver-Automobile-Road-Environment» system (DARE) on road safety. The purpose of the study has been formulated and the research relevance has been outlined.
Materials and methods. Five safety speeds characterizing the interaction between vehicle and pedestrian are reflected. The influence of the stability factor on road safety is described with the help of estimation of critical speeds of wheel drifting, sliding, overturning, aquaplaning (hydroplaning). The peculiarities of the influence of vehicle wheel turning ability on the conditions of safe vehicle operation are presented. The necessity of determining the dynamic dimension, as well as braking and stopping distances is assessed, including consideration of the vehicle equipped with anti-lock system.
Results. The conclusion about the need to assess comprehensively the influence of the most significant factors of each element of the «Driver-Automobile-Road-Environment» system, taking into account their quantitative and qualitative characteristics and features of mutual influence has been made. The authors have developed coefficients for estimation the significance of the “Automobile” factor in the «Driver-Automobile-Road-Environment» (DARE) system. A justification to continue the further studies of the mutual influence of the main indicators in «Driver- Automobile-Road-Environment» (DARE) system has been given.
Discussion and conclusions. The results of the study are intended for the organizations carrying out activities in the field of road safety. This study is an integral part of the development of a general methodology for assessing the indicators of the «Driver-Automobile-Road-Environment» (DARE) system.

Introduction. With the rapid development of highly automated vehicles (HAVs), the issue of adapting existing road infrastructure to ensure their uninterrupted and safe operation is becoming increasingly relevant. Roundabouts, due to their ability to reduce the number of potential conflict points and improve overall safety compared to conventional intersections, are considered as a means of enhancing road safety. However, they are not significantly effective in terms of increasing capacity and optimizing traffic flow.
Materials and Methods. This study is dedicated to a comparative assessment of the efficiency of HAVs on roundabouts. The paper examines the advantages of HAVs, their impact on traffic flow, and analyzes simulation results at the micro (or meso-) level using SUMO software. It demonstrates the influence of different roundabout configurations on the movement of both manually driven and autonomous vehicles within traffic streams.
Results. Simulation results have shown that the use of roundabouts for pure HAV traffic flow is inefficient. Although roundabouts are promoted as a way to improve road safety by replacing conflict points with weaving zones, the algorithmic navigation of HAVs on intersections inherently prevents hazardous situations, as conflicts are resolved in advance. The most critical factor for increasing the throughput of HAVs at intersections is the width of the roadway. At present, no precise quantitative indicators to demonstrate the road width impact on HAVs capacity have been established, however, it is possible to highlight such important aspects as the possibility of uniform traffic flow, typical for piloted vehicles, and, hence, higher volume of HAV traffic flow.
Discussion and Conclusion. The findings of this study can serve as a foundation for optimizing existing transportation infrastructure and developing recommendations for designing intersections adapted to autonomous traffic conditions. They also provide a basis for further research aimed at increasing the capacity of various types of road intersections under high levels of traffic automation.

Introduction. Conducting analysis and assessment of the development of passenger transport routes in the Omsk region taken as an example allows the transportation customer to make an informed organizational and managerial decision for improving the operation of all types of transport. The results of the analysis make it possible to develop measures to ensure the quality of transport services and reduce the total costs associated with ensuring public mobility while complying with current legislation.
Purpose. The study is aimed at assessing and improving passenger transportation organization in the Omsk region.
Methodology. The methods of analysis and data systematization have been used.
Results. When conducting the study, the authors proposed using sampling methods for passenger traffic assessment to clarify statistical data. To define the survey points, the term “Nodal point of the route network” has been introduced. The main directions of inter-municipal passenger transportation and the key transport modes have been identified. The results obtained can serve as the basis for the development of measures to improve the quality of transport services and reduce the total costs associated with ensuring the mobility of the population in the Omsk region in compliance with current legislation.
Practical implications. The results obtained can be used by researchers and specialists involved in passenger transportation organization, as well as in designing multimodal routes and interaction between various types of passenger transport.
Discussion and conclusions. The findings are recommended for improving the route network and organizing passenger transportation within intercity and regional traffic.

Introduction. The most important part of a car is the brake system. Road traffic safety and, most importantly, people’s lives depend on the proper operation of the brake system. The development of brake energy recovery system allows increasing the service life of the brake system and increasing its resistance to overheating.
Materials and methods. This paper examines regenerative braking types. The KERS (Kinetic Energy Recovery System) system and its types, recuperation of braking energy via a kinetic flywheel and a motor generator have been considered. The paper examines hydraulic recuperation or Hybrid Air system, and calculates the regenerative power of a kinetic flywheel as applied to domestic cars.
Results. It is assumed that for the implementation of the recovery system in domestic cars, it is more profitable to use mechanical recovery, since it is cheaper than other types, easier to install and manufacture. Recovering braking energy via a kinetic flywheel leads to about 7 horsepower delivered to the car wheels. The remaining energy is spent on spinning the flywheel and losses in the system mechanisms associated with transmission from the flywheel to the wheels. The energy that was previously spent on heating the brake discs and brake pads is now spent on spinning the flywheel, thereby reducing the temperature of the braking system mechanisms.
Discussion and conclusions. In the course of the analysis of design and technological solutions, as well as the calculations performed, it can be concluded that the use of a kinetic recuperative system on the LADA KALINA-2 vehicle under study will allow an additional 7 horsepower to be obtained in the city cycle of vehicle operation during 6 seconds of operation of the recuperative system.

Introduction. The article is devoted to increasing the productivity of transport and warehouse processes with an emphasis on the analysis of operations performed in the warehouse. Household appliances and electronics retailers have been taken as an example for solving the problem, but the results of the study can be extended to retail systems based on traditional and online technologies.
The productivity of integral parts of transportation and warehousing for the stores under investigation, such as vehicles for delivering goods and warehouse workers, has been given a differentiated assessment. The problems associated with unbalanced warehouse operation during peak sales periods are considered. The relevance of the study refers to statistical data confirming the growth of sales in this market segment. The purpose of the study is to develop a mathematical model that determines the relationship between the output of a warehouse of household appliances and electronics stores and the output of vehicles transporting goods.
Materials and methods. The method of optimization of technological processes was used to develop the mathematical model. The solution of the problem is achieved through using the search method for output physical indicator with the adopted restrictions taken into account. Elements of transport and warehouse processes for mathematical description include the output per each warehouse worker performing a specific operation; the output of each vehicle performing a specific task in the warehouse. Planning is considered on daily basis for the specific month of the year.
Results and conclusions. The developed mathematical model defines that the output of all workers and rolling stock units ensures the necessary operations for processing the goods received at the warehouse. The mathematical model prescribes the required number of warehouse workers and vehicles, taking into account the output of the entire work according to the efficiency criterion – profit. Directions for further research on practical implementation of the mathematical model include determining the probabilistic parameters of the model – output of warehouse workers and vehicles, time for processing an order by groups.

Introduction. The balanced (sustainable) development of road transport, coordinated with other elements of urban infrastructure, the correspondence of transport demand and supply, the formation and implementation of effective strategies for the development of public road transport is the most important modern problem. Within the framework of this direction, one of the urgent unsolved tasks so far is to determine the number of reserve fleet of the rolling stock for reliable transport services. In practice, the shortage of rolling stock is often the reason for the low coordination of the logistics process, disruptions in the work of road carriers, fines for non-performance of the contractual obligations to the customer and for violations of the law.
Materials and methods. To ensure the necessary reliability of the transport system, it is necessary to determine the required level of rolling stock reserve. The work presents a method for solving the stated problem, based on the apparatus of the theory of probability and mathematical statistics. The methodology allows calculating the safety size of the rolling stock reserve, which ensures the specified reliability of the transport system, which is established taking into account factors determined by the specific conditions of the transportation process.
Discussion and conclusion. The practical effectiveness of the proposed method is shown by the example of solving the problem for the conditions of a real transport organization. The technique has been successfully tested and is currently being applied in practice.

Introduction. The article presents information on accidents that occurred on the roads of the Russian Federation, the USA, China, Cyprus, and India due to insufficient shear resistance of weak soils at the base of the embankment. Therefore, the analysis of methods for calculating the stability of weak foundations of road embankments becomes relevant.
Materials and methods. The famous methods for determining ultimate loads are divided into calculations: by the first critical load, analytical and numerical solutions of the theory of limit equilibrium of soil, and calculations performed by the finite element method. Each method has been analyzed. Particular attention is paid to the solution of Evgenyev - Kazarnovskiy. This solution is considered to be a generally accepted method for calculating the weak foundation of highway embankments. The authors have demonstrated the derivation of formulas for calculating the stability coefficient of the weak foundation and safe pressure. The advantages and disadvantages of this method have been noted. The specific features of the finite element method applied to calculate soil foundations have been considered. The disadvantages of the PLAXIS and MIDAS software packages, found by the specialists of the Siberian State Transport University (Novosibirsk), have been presented.
Results. The calculation of the embankment base stability by shear stress, which is the equivalent to the stress of the Mohr-Coulomb criterion, has been presented. The proposed calculation is the analogue of the calculation by the first critical load.
Conclusion. The obtained results allow us to make weak embankment bases calculations. The goals for the authors’ future research have been set.

Introduction. Fine-grained concrete has been widely used in construction industry of China and has remained the most "revolutionary" material in concrete construction technology over the past 10 years. Due to the rapid development of urban construction, land development, characterized by special environment and climate conditions for building high-rise and super high-rise buildings and structures, the development of highly efficient fine-grained highstrength concrete for foundations is required. Pile foundations are of particular importance in modern construction.
Results. The article presents the results of obtaining fine-grained concretes of B25 and B30 classes with the developed composite binders for pile foundations having an increased water permeability W8 and frost resistance F300.
Discussion and conclusion. The study of the microstructure showed a dense overgrowth of the pores of the cement stone, calcium and aluminum hydrosilicates were distributed in a uniform fringe on the contact zone with the aggregates, tightly fused into a single hydrogranate. It has been shown that for the compositions of fine-grained concretes with composite binders the cement consumption in the developed concretes is reduced by 12 per cent, while ensuring the required normative strength and increased water permeability and frost resistance. Taking into account the specific environment and climate conditions for soils in China, the developed composition will ensure high water resistance and durability of fine-grained concretes for pile foundations.

Introduction. Modern construction process is carried out mainly by the production line method. Time is money. This means that the speed of creating the final product plays a major role. However, the use of the production line method requires continuous functioning of the entire organizational and technological system. Any element that falls out of it can lead to a breakdown of all processes and, ultimately, to an increase in the construction period. Labor resources in construction is a parameter that is sometimes more difficult to be taken into account compared to materials that vary in price. This is due to the fact that such resources are living resources, which means that the uncertainty factor should be of much greater importance compared to calculating other resources. The purpose of this study is to develop a scientific and methodological approach to designing construction flows in conditions of qualified labor shortage aimed at reducing the number of downtimes and, as a result, increasing labor productivity. As a research model, a situation was used in which, on the one hand, due to technological features, different numbers of workers are needed at different sites, and, on the other hand, there is uncertainty with labor availability.
Materials and methods. In the study mathematical statistics has been used. The database was formed based on the information from open sources, as well as information from construction contractors the author worked for as a post-graduate student of the Don State Technical University. The reliability of this data was confirmed during long-term cooperation of these enterprises with the university and a fairly large sample of statistical data. Regular monitoring production standards compliance at the enterprises under the study, analysis of time parameters of the flow, monitoring resource consumption, analysis of work quality were used. Methods for solving current problems related to labor force were recorded. The experience of construction organizations has shown that combining occupations is very productive, when a worker from one professional field can temporarily (from one day to several weeks) work in another profession.
Results. The study allowed to: identify the reasons for the shortage and turnover of workers (lack of qualified personnel in the required profession on the labor market, low salary level, small benefits, high morbidity rate, seasonal nature of some jobs, etc.); suggest measures for minimizing the personnel turnover in construction; calculate the construction flow with unstable teams of workers; propose measures to neutralize the uncertainty in providing workforce for construction flows (to optimize personnel issues in flow construction); develop proposals for combining blue-collar jobs; analyze the results of implementing the proposed measures.
Discussion and conclusions. The practical value of the study is related to the possibility for construction organizations to solve the problem of labor shortage without using economic methods and without spending significant funds. The results of our study have been practically implemented. In the future, it would be desirable to conduct a study in the field of psychology on the rapid adaptation of temporary workers. Psychological aspects are very important in cases of frequent replacement of workers. This is especially important in situations with temporary works organization, since it is impossible to provide a long gradual adaptation of workers.