Introduction. Vibratory plate compactors are soil compaction machines with a flat operating device, which is put into a state of oscillatory motion by a vibration exciter. The variety of designs of vibratory plate compactors is one of the reasons for significant variations in their main parameters for the corresponding mass ranges. In order to improve the design methods for self-propelled vibratory plate compactors, an analysis of existing designs has been made. The impact of design on the technical characteristics of vibratory plate compactors has been analyzed.

Materials and methods. The study analyses data on the designs and technical characteristics of vibratory plate compactors, presented on the websites and in accompanying materials of manufacturers, as well as their dealers. A total of 1,137 models of reversible and forward vibratory plate compactors manufactured by Russian and foreign companies were reviewed.

Results. The design features of vibratory plate compactors have been identified, the ranges of their main parameters have been established. The relationship between the layout of self-propelled (especially, electric) plate compactors and their technical characteristics and analytical models has been analyzed.

Conclusion. The scattered main parameters of reversible and forward plate compactors are partly due to the design features of the plate compactors, such as number of unbalanced shafts, the nature of vibrations, the type of transmission, etc. Most of vibratory plate compactors must be considered as two-mass oscillation systems with elasto-viscous bonds when modeling. A number of electric plate compactors are single-mass oscillation systems, which affects the patterns of their interaction with the ground. The base plate shape influences the magnitude of contact stresses, the number of cycles of load applications to one point of soil in one pass, the compaction depth and maneuverability.

Introduction. The article presents studies of the possibility of increasing gas pressure in one stage. Reciprocating compressors of road construction machines have been investigated, for which, as for any mobile stations, the issue of reducing the weight and size parameters of process equipment is acute. In this regard, the aim of the work was to expand the range of pressures obtained in single-stage piston machines. An alternative to the use of existing compressors with lubricated flow part can be compressors with seals based on fluoroplastic compounds that do not require liquid lubrication. In this regard, an urgent task is to determine the range of pressure ratios with a limitation on the operating temperature of non-lubricated seals. The increase of the pressure in one compression stage will significantly improve the efficiency of mobile compressor units, including applied for road construction works.

Materials and methods. Based on the developed mathematical model of concentrated gas parameters, theoretical studies were carried out to determine the temperature of the cylinder-piston seals of the compressor. The article presents simplifying assumptions adopted in the mathematical model and a system of calculation equations, the main among which are the equation of the first law of thermodynamics, the equation of state, the equation of work and the equation for calculating mass flows through leaks in the working chamber and valves.

Results. The diagrams of average temperature change for single-stage machines and for the case of short-term compressor operation were obtained on the basis of theoretical studies. The temperature limit has been set at
+200 0С, which is typical for the studied fluoroplastic-based materials.

Discussion and conclusions. Promising results were obtained that showed the possibility of expanding the pressure range in a single-stage machine. In cases where strict conditions for gas temperature are not required, the pressure ratio in such compressors can reach 16. In this case, the receiver volume can be reduced to 44%. The option with short-term compressor operation from 15 to 45 minutes has also studied, where the range of the pressure ratio can be increased to 28 ... 30, but the compressor cooling time must not be less than 1 hour.

Introduction. The degree of passenger capacity and operating time of route vehicles’ utilization determine the work efficiency of regular passenger transport. Therefore, the development of measures to increase the effectiveness rate of passenger load factor use of route vehicles, to reduce its unproductive downtime is relevant to fasten the payback period of regular passenger transport and allows to enhance the efficiency of its operation.

The reason for low passenger load factor utilization of the route vehicles and high values of its inefficient downtime is the unevenness of passenger flow. The existing route-by-route method of work organization consists in the fact that vehicles go out on the line to one route. Its number, capacity, movement interval depend on peak values of passenger flow. During off-peak times, periods of on-duty traffic, the quantity of passengers decreases sharply, which leads to the declining in the degree of route vehicles’ capacity utilization. To ensure the acceptable values of this passenger load factor use, transportation operators increase the traffic interval by extension of unproductive downtime duration at the end points, which affects negatively the efficiency of regular passenger transport.

The aim of the research is to develop a new method of organizing the work of route vehicles, which allows to increase the efficiency of regular passenger transport.

Materials and Methods. Methods of analysis and generalization of literary sources, the principles of graph theory, formalization and mathematical formulation of the objective function and constraints were used while writing.

Conclusions. A multi-route method of the work planning of route vehicles is proposed, which consists in the optimal distribution of trips of all routes of the considered route network between the fleet of available route vehicles, allowing to reduce its unproductive downtime and to increase the effectiveness rate of passenger load capacity utilization due to the possibility of route vehicles’ use on different routes, which will decrease the cost of such trips.

For optimal distribution of trips of all routes of the considered route network between the fleet of available route vehicles, such trips are represented as vertices of the attributed graph, and possible activities between trips (idle time, empty runs) – as arcs. The set of vertices and arcs of such a graph represent cycles, each of which is a set of trips to be performed by a route vehicle during the operation time. In order to select a set of cycles, providing minimum costs for the carrying out all trips, the corresponding objective function was formulated. To ensure conditions objectively existing for route vehicles operation, a number of constraints were imposed on the objective function.

Potential Application of Research Results. The results obtained represent an objective function and constraints that enable the implementation of a multi-route method for organizing public transport vehicles’ operation. Results can be applied to a city’s transport network to improve the efficiency of regular public transport services by reducing operational costs without deterioration in the quality of the provided services for the passengers.

Practical Significance. The proposed multi-route method of work operation of regular public transport vehicles allows to shorten the operating costs by increasing the effectiveness rate of passenger load factor use and reducing unproductive idle times. This method does not diminish passenger service quality as it does not involve canceling trips and (or) prolongation of the intervals between vehicle routes.

Originality in academic context. This work presents a novel method for organizing the operation of public transport vehicles, which helps to cut the operational costs without compromising the service quality. The article will be useful for public transport governing officials responsible for organizing urban regular public transport, as well as employees of urban public transport enterprises and transport industry researchers.

Introduction. The article considers the need for a comprehensive assessment of the quality of transport services in the field of regular passenger transportation, justified by changes in both the provisions of the legislation of the Russian Federation and the requirements of the main consumer of these services – passengers. It is proposed to consider the issues of improving safety and comfort at large transport transfer hubs. The territory near the Omsk region railway station is chosen as an example.

Materials and Methods. The work uses current regulatory legal acts of the federal and regional levels in the field of public transport services, data from the sociological survey of passengers, the results of measurements at the endpoints of the current route network of the Omsk region, existing registers of inter-municipal and municipal routes. The following research methods were used: analysis, survey, formalization.

Results. Based on the analysis of statistical information and field observation data, the daily number of passengers and vehicles departing from the territory located near the Omsk railway station were determined. The obtained data allowed us to conclude that the studied territory with the second largest volume of passenger flow has absolutely no infrastructure that ensures the comfort and safety of transferring from municipal transport to inter-municipal routes. Based on the approved standards, the structure and area of the public transport complex have been determined, which makes it possible to eliminate the identified shortcomings.

Discussion and conclusions. The obtained results suggest the need to organize a public transport complex and the possibility of its location on the territory near the railway station.

Introduction. The current problem of road safety state (RTS), which appears mainly in the deterioration of the demographic situation in the Russian Federation (RF), results in the need for a significant strengthening of state activities in increasing the level of road safety. To assess the level of road safety, a system of indicators is used based on the analysis of the number of road accidents with traffic flow density, motorization level, the number of people, etc. taken into account. 80 per cent of road accidents occur in populated areas, the vast majority of them taking place in the subjects of Russian regions. At the same time, about 90 per cent of accidents occur due to violation of traffic rules by drivers, 10 per cent – by pedestrians. Today, among 89 regions of the Russian Federation, there is significant heterogeneity, determined by a number of indicators related to the territorial location, economic, social and climatic conditions that affect certain human actions (human factor) as related to a participant in street and road traffic.

The purpose of the study is to determine indices for comparing cities in the road safety rating.

Materials and methods. The methodological basis of the research is mathematical and statistical assessment methods.

Results and discussion. The main result has been determination of parameters affecting the state of road safety. Eight indices have been grouped that characterize the level of road safety taking into account parameters of the human factor. A most important road safety parameter has been established, by considering the human factor in the “man – car – road – environment” system.

Conclusion. A new methodology for assessing the level of road safety in urban environment is proposed. Identifying the subjects of the Russian Federation is most appropriate for making priority management decisions aimed at improving road safety, taking into account the human factor. The methodology will make it possible to assess the effectiveness of solving key tasks related to the prevention of road accidents, the implementation of federal targeted programs and strategies in the field of road safety in the regions of Russia.

Introduction. The main purpose of the work is to determine a parameter characterizing conditions for effective operation of electrically powered vehicles. It has been found that the use of electric vehicles is associated not only with environmental performance, reducing operation costs, but also with limited mobility of both individual owners of passenger cars and owners of commercial vehicles. The limitations are related to the cost of new cars and technical characteristics – power reserve, charging time of traction batteries and charging infrastructure. At the same time, it is necessary to take into account the operating conditions that affect the power reserve, and therefore the number and time of charging operations, which affect the operating cycle length and the maintenance cycle of electric vehicles. The paper presents a mathematical model for efficient operation of electric vehicles, taking into account the relationship of the technical characteristics of cars, charging infrastructure with the purpose and operating conditions of cars.

Materials and methods. The results of a survey into opinions of car owners about the conditions of electric vehicles operation, modeling of electric vehicles operation, and classifications have been used. The results and recommendations for the technical operation of electric vehicles are described, depending on the purpose and operating parameters.

Results. As intermediate results of the conducted research, the boundary values of the parameter of the efficiency of using electric vehicles were obtained, which makes it possible to justify their operating modes.

Discussion. It is noted that the approach implemented in determining the efficiency parameter for electric vehicle operation makes it possible to reasonably carry out measures to develop both the fleet of electric vehicles and the infrastructure that ensures their efficient operation.

Conclusion. It has been concluded that the efficiency parameter proposed will make it possible to assess the prospects for the use of electric vehicles, depending on the field of activity and operating conditions.

Relevance. Currently, vehicles with electromechanical power transmission and electrochemical battery as the energy source are being registered on the road network. These are electric vehicles used as personal transport, electric buses as public passenger transport, electric cargo vehicles used for various needs. The main feature of this transport is related to providing the required power reserve for 1 charge. To do this, it is necessary to use advanced power transmission components, energy sources and control methods to minimize energy consumption. Since the processes in the electromechanical power transmission run at high speeds, in the motor control circuit with frequencies up to 10 kHz or more, situations of exciting oscillatory phenomena occur where low inertia and rigidity of the external mechanical characteristics of the electric motor are observed. In particular, the modes of changing driving conditions (traction, driven, braking) are of importance, which are accompanied by a change in the direction of force in the contact zone of the wheel and the road and the direction of load application in the gears. This process is accompanied by reconnection, i.e. meshing of the other side of the teeth. With a rapid change in torque, this process can be accompanied by a shock followed by excitation of frictional vibrations. Therefore, it is important to effectively control the torque to eliminate these negative consequences.

The purpose of the study. It is necessary to check the influence of the S-shaped law of torque setting in the control of an electromechanical power transmission on the dynamic load of a mechanical transmission and on the energy efficiency of movement.

Materials and methods. The study of the influence of the law of torque setting was carried out based on experimental research methods.

The results of the study. The S-shaped law of torque setting has shown the possibility of eliminating vibrations excitation when changing the driving mode and the direction of load application in the mechanical transmission of the power transmission. A high value of the regenerative torque when releasing the pedal and moving in braking mode results in reduced movement efficiency, increased specific energy consumption per 1 kilometer.

Conclusion. The application of the S-shaped law of torque setting is suitable for the implementation of motion control algorithms and software.

Introduction. For the manufacturer and consumer enterprises of the products, it is of interest to know the real operational reliability of power units of KamAZ vehicles, their weakest points, the causes of premature failures, as well as methods for identifying and preventing their occurrence, and therefore carry out scientific research aimed at solving the above task is relevant and timely.

Methods. The study of the reliability of systems, components and assemblies of engines of KamAZ vehicles was carried out in the conditions of the official dealership center “Technical center Severny” (Irkutsk), specializing in the sale, maintenance and repair of KamAZ vehicles during 2020–2024. the study involved KamAZ vehicles with 740 engine, including those under warranty. The automobiles with these power units were operated primarily in the Irkutsk region, including server regions. at the same time, each work order recorded the reason for contacting the service, the mileage of the car, as well as the types of work performed. An important step was to identify the distribution law of the most frequent failures of engine systems and components.

Discussion and conclusion. The analysis of the data obtained during the study indicates the predominance of two types of premature failures – cylinder heads, as well as fuel supply systems, primarily electrohydraulic injectors. It was found that premature failures of cylinder head and electrohydraulic injectors obey the Weibull distribution law and have mathematical expectations of a failure time of 49.6 thousand km for injectors and 41.9 thousand km for cylinder heads. At the same time, the failures of the cylinder head of the highly accelerated engines of the KamAZ-740.7 family (with a capacity of over 360 hp) are caused by increased thermal stress and can be classified as structural and operational.

Introduction. Over the past seven years, the demand for the use of personal mobility devices (PMDs) has grown significantly. However, behind the popularity of these transport means is a rapid increase in the number of road accidents. In order to assess the changes of the situation in the field of accidents involving application of individual mobility devices on the scale of Moscow, a mathematical model was developed to predict the impact of the number of individual vehicles on accidents, namely road accidents.

Materials and methods. This article presents the results of mathematical modeling based on the influence of the number of personal mobility devices (PMDs) on the number of accidents involving them. To achieve these results, the science of econometrics was applied, which studies quantitative and qualitative economic relationships using statistical and other mathematical methods and models, as well as regression analysis, which allows us to study the effects of one independent variable on the dependent one. The statistical significance of the regression equation as a whole and individual regression and correlation parameters was assessed.

Results. The mathematical model has been created to predict the number of accidents involving personal mobility devices (PMDs) for Moscow, depending on the number of this type of moving vehicles on the street and road network.

Discussion and conclusion. The use of the given model will let with the help of linear equation of paired regression predict the number of road accidents depending on the quantity of personal mobility devices (PMDs) on the street and road network, which will allow for a certain probability to assert the increase in accidents involving these types of transport devices.

Introduction. Under modern conditions construction companies have to be highly flexible and able to quickly adapt their organization structure and personnel to the requirements of each project. To achieve maximum effect in completing construction tasks, it is important to improve organization structure and staff composition taking into account costs. Given the specifics of construction work, high technical complexity of objects and the need to meet strict deadlines, approaches to organizing management processes should take into account both technological and qualification factors, and the costs of allocating labor resources.

This article discusses methods for improving organization structure of construction companies with an emphasis put on increasing efficiency while meeting deadlines.

Materials and methods. The study uses methods of system analysis to assess the current efficiency of the organization structure of construction companies. To identify ways to improve the staff structure and distribute tasks among employees, mathematical models based on cost and productivity analysis were used.

The analysis of factors affecting the operational staff structure included employee qualifications, specifics of construction work and their technological features. Considerable attention has been paid to the costs on training and advanced training of employees, taking into account the requirements of various types of construction projects.

Scientific novelty. The paper proposes new approaches to improving organization structure of construction companies aimed at redistributing tasks and functions among employees taking into account the specifics of projects. The developed model allows to optimize staff composition, provide capability of the organization structure to respond promptly to changes in the construction process. Evaluation of costs and productivity at each stage of construction works helps to increase the reliability and efficiency of project implementation.

Results. The conducted research has shown that improvement of the organization structure and staff composition of construction companies requires application of an integrated approach to the redistribution of labor resources. This includes an emphasis on improving the qualifications of personnel, clarifying functions distribution and improving interaction between departments. Optimization of personnel costs, taking into account the complexity of construction tasks, allows to increase productivity, coordination and provide implementation of construction projects according to technical requirements.

Discussion and conclusion. The results of the study prove that improving the organization structure and staff composition of construction companies in terms of costs is an important factor in the successful implementation of construction projects. Optimization of these elements leads to reducing costs, meeting deadlines for work and increasing the reliability of construction processes. Prospects for further research include improving methods for assessing the effectiveness of various construction departments and integrating innovative technologies into construction organization processes.

Introduction. Carrying out major repairs is one of the main activities for achieving the goals of long-term preservation and normal operation of buildings and structures. Basically, major repairs are connected with the same problems as construction. However, major repairs may include difficulties that are not typical for construction. Due to this, the topic of major repairs still remains very relevant in modern publications and not all aspects of its organizing have been studied well. The purpose of this study is to develop an evaluating model for determining the realization quality at organizational and technological stage of major repairs of buildings (structures). To achieve this goal the following tasks have been set: to identify problems arising in the field of organization and technology of major repairs; to detect the factors affecting the fulfillment of major repairs; to develop a formula for determining the quality of organizational and technological level in major repairs and to make proposals for its improvement.

Materials and methods. Theory of multiple principles, method of expert assessments and mathematical statistics were applied in the study. To conduct the necessary experiments and analyze their results, the production resources of the Don State Technical University were used, as well as data from the number of customers of major repairs. Representatives of these customers, first of all, were involved as experts for assessing the organizational and technological level of contractors performing major repairs of buildings and structures. The quality level of major repair organization is most appropriately to be determined by three characteristics - quality, speed of execution, price. If the first two indicators are high, and the third is the lowest, it can be said that the level is the highest. To estimate more accurate the performance level of major repairs, it is necessary to take into account not only the value of the indicators of the factors, but also the values of the characteristics of these factors, as well as the significance of the indicators of these characteristics.

Results. The study allowed to systematize organizational and technological problems of major repairs; to define the factors influencing the organizational and technological level of major repairs of buildings (structures); to propose a model for its determination; to identify the characteristics of the factors influencing it; to develop a formula for evaluating the organizational and technological level of major repairs; to propose an algorithm for estimation the general organizational and technological level of major repairs; to derive, using a practical example, the significance of the factors influencing the execution quality of major repairs; to give proposals for improving the organizational and technological level of major repairs.

Discussion and conclusions. The practical value of the work for major repair customers is that, applying the proposed methodology, they can choose a contractor with a higher performance level, and contractors can improve their level using our methodology. Identification and systematization of problems in organizing major repairs by us can help all participants taking part in major repair relations in terms of neutralizing such problems at the early stages of preparing for major repairs. The obtained results of our practical survey were taken into account developing contractor activity plans, on the basis of which the research had been conducted. By developing the study, it will be possible to supplement the number of factors influencing the organizational and technological level of major repairs, as well as identify a range of other characteristics of these determinants and systematize the lists of factors and characteristics.

Introduction. Current problems of human life quality are taking on a global character and manifest themselves in environmental degradation and the activation of abnormal man-made and natural processes. The solution to the problem of creating comfortable human living conditions is possible through the use of new technologies and approaches; rational use of mineral raw materials, taking into account their genesis. The use of rocks specially prepared by geological processes is especially relevant.

Results. It has been established that the composition and properties of weathered quartzite sandstones have a significant effect on the structuring processes of the composite binder. Ca(OH)2, released during hydration of clinker minerals, interacts with amorphous phases of this rock to form calcium hydrosilicates of the second generation, which leads to optimization of the cement stone structure.

Conclusion. The results of scientific research indicate an improvement in the strength characteristics of composite binders based on weathered quartzite sandstone in all cases compared to binders based on unweathered quartzite sandstone. Maximal value is obtained for KV20 composite binder (with filler consumption up to 20 per cent), which is 23 per cent higher than strength characteristics for specific surface area of cement from 500 to 700 m2 /kg, with accompanying compaction of the composite material.