Introduction. The problem of fast and high-quality road construction, when economic facilities and settlements are spatially separated, located at a considerable distance from each other, cannot be solved without the use of a complex of continuous units. An important element of the continuous unit forming the ditch and the unit for tunneling is the direct-flow rotary ripper. Current theoretical studies are not sufficient to calculate the interaction with the soil of the elements of a direct-flow rotary ripper. The lack of theoretical justification for the parameters of direct-flow rotary rippers hinders their use. Therefore, there is a need for theoretical research to identify the geometric, kinematic, dynamic and energy parameters of structural elements.

The method of research. Methods for calculating the required power to drive the teeth, to separate the seam from the soil mass with knives and divide it into fragments, to overcome the inertia force of the incoming soil on two small rotor knives, to accelerate the soil towards the large rotor, to move the soil towards the large rotor, to overcome the friction force of the soil on the front surface of the knives have been developed. The total power required to drive the small rotor corresponds to the sum of the powers: for the introduction of a cone with a spiral knife into the ground, for the drive of the teeth and for the drive of the knives.

Results. On the basis of the developed methods, the parameters were calculated. From the flat and spatial model of the forces of interaction with the ground of the elements of the small rotor, their resultant, their components, and normal forces are revealed. The friction force of the soil on the front surface of the knife is calculated. The total power for the drive of the small rotor and the volumetric energy for the introduction of the small rotor into the ground are calculated.

Conclusion. The energy costs for driving small rotor knives include: energy for separating the reservoir and dividing it into fragments, energy for overcoming the pressure of the soil on the front surface of the knife, energy for accelerating the soil, energy for moving the soil, energy for overcoming the friction force of the soil on the front surfaces of the knives. The total energy cost of the small rotor drive includes the energy required to introduce the spiral knife cone, teeth and knives of the small rotor into the ground. As a result of the calculations, the power to drive the teeth of the small rotor is 735 W, the total power required to drive the small rotor is 2.2 kW. The volumetric energy for the introduction of a small rotor into the ground is 33.1 kJ / cubic meter.

Introduction. Over the years of cooperation between foreign manufacturers and domestic operating enterprises, a significant amount of construction equipment has been supplied. In this regard, there is a need to develop and improve existing standards governing the methodology for calculating the operating modes of construction machines. Often, the use of indicators given in regulatory documents shows a significant discrepancy in comparison with the actual indicators obtained characterizing the annual operating modes of machines. The article presents a method for calculating the annual duration of technical maintenance and repairs (TM and R) using the example of single-bucket hydraulic excavators of domestic (EOD) and foreign production (EOFP).

Methods and materials. The method is based on the obtained patterns of changes in operating time between failures, the duration of maintenance and repair of analogues of EOD and EOFP.

Results. As the studies have shown, over the course of operation, the annual duration of maintenance and repair in the EOD increases by 1.73 times, and 1.13 times in the EOFP; the duration of a single maintenance and repair in the OED is 2 times, and 1.4 times in the EOFP; the average time between failures in the EOD is 1.65 times less than in the EOFP at the studied intervals. The indicator of the duration of the EOD in TO and P for 1 operating hours, based on the dependencies obtained, shows an excess of 4.25 times, and according to the regulatory source MDS 12-8.2007, it is 6.03 times higher than that of its foreign counterpart.

Discussion and conclusions. As a result of the application of the proposed method, the annual fund of time costs associated with maintaining and restoring the working technical condition can be predicted not only for domestic, but also for foreign single-bucket hydraulic excavators, the accuracy of planning the work performed increases compared with existing standards, this enables to take into account the unevenly distributed annual downtime depending on the planned working time, this will have a positive effect on the planning of the use of equipment. The data obtained can be used for the EOFP of the 5-th standard-sized group as normative

Introduction. The article discusses the requirements for equipment for removing pile caps of reinforced concrete piles. The machines produced nowadays have excessive power and strength parameters which has been noted and proved experimentally.

Materials and methods. Using a prototype of operational equipment on the different piles of different cross-section the force parameters of the working process, the character of development of cutting resistance forces in the cycle were investigated.

Results. The stick-slip nature of cutting resistance forces and then a sharp drop of these forces on the whole area of theoscillogram indicates the brittle character of the pile fracture. It is also noted that the dependence of head shearing resistance forces on the height of the pile cap is linear. Technological and constructive features of the new equipment were investigated. High productivity of the machine as a whole was shown.

Discussion and conclusion. Based on the results of the tests, the authors concluded that further work on the study of the working process of removal of reinforced concrete pile caps is reasonable.

Introduction. The theoretical basis for the development of indicators for improving the training and retraining of road transport personnel is aimed, first of all, at ensuring the results of transportation and technical operation activities corresponding to the output in road transport. The studied indicators should take into account the amount of labor costs of all types of workers ensuring the operation of rolling stock. Training and retraining of personnel largely determine the safety of the transportation process and must comply with the existing operating conditions of rolling stock. The purpose of this article is to theoretically substantiate the indicators for improving the training and retraining of specialists and personnel of road transport, as an element of the “personnel-bus-road-operating environment” (PADS) system to ensure the planned production of rolling stock in accordance with the requirements of the municipal contract for regular passenger transportation and luggage, taking into account operating conditions.

Materials and methods. The theoretical basis for the development of indicators for improving the training and retraining of personnel is based on a systematic analysis of professional and qualification requirements, as well as the theory of current planning of the work of motor transport enterprises, taking into account the probabilistic nature of operating conditions under the influence of the external environment. As a result, structural connections between the driver, mechanic and technical condition inspector were identified as elements of the new PADS system.

The parameters of the developed mathematical model of personnel activities and the costs of their training and retraining are determined using methods of mathematical statistics and expert assessments. The content of the new approach is to integrate the production of rolling stock with professional and qualification requirements for personnel.

Results. This study focuses on fulfilling the municipal contract for regular transportation of passengers and luggage, i.e. to obtain the planned mileage, it is necessary to take into account the joint activities of groups of personnel and in each group of an individual employee.

Discussion and conclusion. The scientific novelty and main results of the study consist in the theoretical substantiation of indicators for improving the training and retraining of passenger road transport personnel, as an element of the PADS system, to ensure the planned production of rolling stock, taking into account operating conditions.

Based on the results of the study, the indicators of training and retraining of personnel of automobile passenger transport, ensuring the fulfillment of the contract, are grouped in accordance with their levels and periods of formation.

A mathematical model that determines the planning of the results of fulfilling the terms of the contract by each employee has been developed. Further research will be aimed at experimentally determining the values of the identified indicators.

Introduction. The problems of the mass use of electric buses on urban routes are low operational indicators, including the life of traction batteries (TAB), a significant limited autonomous travel compared to motor vehicles based on internal combustion engines, high cost of batteries, limited implementation of charging infrastructure, deterioration of efficient operation at low ambient temperatures, etc. Most operating parameters depend on the efficiency of replenishment, storage and consumption of electricity on board the electric bus, which include: power reserve, TAB life and economic costs for operation.

Materials and methods. The work uses methods of numerical modelling of the movement of the KAMAZ 6282 electric bus under the conditions of the SORT 2: MIXED test cycle.

Result. In this work, the balance of electric energy on board the КАМАZ 6282 electric bus during its operation on the city route was analyzed, and the search for the most rational ways of its consumption was carried out due to the introduction of thermal control systems for the passenger compartment and the driver’s workplace based on the installation of a heat accumulator (HA) with phase transfer heat accumulating materials (PFTAM).

Discussion and conclusion. The installation of the proposed PFTAM-based system, provided that the range is provided at the level of the serial model, enables to reduce the battery capacity by 24% (up to 549 MJ) or, while maintaining the capacity of 720 MJ, increase the range by 44% up to 130 km.

Introduction. The high importance of the urban passenger transport complex as a system determining the level of socio-economic development of the urban area is formulated. One of the systemic problems of the passenger transport complex of modern cities is the decentralization of planning and management processes, which determines the structural imbalance of key subsystems. The results of a literary review are presented, during which the works devoted to improving the efficiency of the transport process, the process of providing energy resources and the process of maintaining rolling stock in good condition are considered. The necessity of developing a methodology ensuring the coordination of the state and functioning of key subsystems of the transport complex is noted. The purpose of scientific work is defined, the list of solved tasks is defined.

Materials and methods. The structural scheme of the urban passenger transport complex is given, a conceptual approach to solving the problem of coordinated optimization of its key subsystems is described. The following are defined: the target indicator, the objective function and its limitations that determine the optimization process being implemented. A brief description of methods for determining and mutual coordination of structural parameters of subsystems forming the material basis of the transport complex is given.

Results. Theoretical provisions reflecting a conceptual approach to ensuring the efficiency of urban transport systems based on the coordinated development of subsystems, based on the magnitude of the proposed integrated efficiency indicator, are presented. Based on the data obtained from the results of analytical studies and field experiments, a calculation was made that made it possible to determine the structural parameters of the subsystems of the urban passenger transport system of one of the cities, ensuring the maximum value of the efficiency of transport activities provided by structural coordination of the subsystems that make up the material basis of the urban passenger transport system.

Discussion. The solution of the tasks set is reflected, indicators reflecting the achievement of the research goal are indicated, confirmation of the hypothesis about the possibility of improving the efficiency of the urban passenger transport complex through the implementation of conditions ensuring the coordinated development and interaction of key subsystems is formulated.

Conclusion. A generalizing conclusion about the solution of an important scientific, methodological and applied task – to increase the efficiency of the passenger transportation process along urban passenger transport routes based on ensuring the coordinated development of the subsystems that make up its material base is formulated.

Introduction. As part of solving the urgent problem of forecasting technical impacts and residual life depending on operating time, a method for determining the effect of the starting mode on a change in the structural parameter determining reliability is presented. The essence of this technique and its novelty consists in combining two full-factor experiments to determine the effect of operating conditions on changes in the structural parameters of the engine. The purpose of the scientific study is to determine the effect of the starting internal combustion engine on the change in the performance characteristics of the engine.

The novelty of the article lies in the combination of two full-factor experiments to determine the effect of operating conditions on changes in the structural parameters of the engine that determine its reliability.

The reliability of the car (individual reliability properties or technical readiness) is influenced by the following factors: operating modes, operating conditions, quality of spare parts, qualifications and experience of drivers, etc. These factors show the direction and degree of the influence on the car and its reliability (technical readiness). The paper examines the influence of each factor on the reliability of the car.

Methods and materials. To determine the effect of the starting mode of an internal combustion engine on a change in the structural parameter during forecasting, it is necessary to develop a methodology for determining the effect of the starting modes of internal combustion engines on changes in the structural parameters of the engine that determine its reliability. This technique involves conducting a full-factor experiment with four factors, i.e. 16 experiments. The combinations of different levels of factors are accepted as operational modes.

To measure the magnitude of the influence of each factor on reliability, the article considers their measured values - indicators of the factor. There are from one to several indicators per factor. The values of the indicators are not constant, but change in accordance with changes in external influences (factors). Indicators are calculated based on the values of certain indicators of the direction of the influencing environment that a particular indicator describes.

The total duration of the tests is assumed to be equal to the resource before major repairs.

Results. The authors propose a method for determining the effect of starting modes of internal combustion engines on changes in the structural parameters of the engine that determine its reliability.

The starting modes of the internal combustion engine and the dependence of reliability properties on external factors affecting the car at the time of engine start are considered. It is established that the degree of influence of factors is measured by the values of their indicators.

Conclusion. As a result of using the proposed methodology for determining the effect of starting modes of internal combustion engines on changes in the structural parameters of the engine that determine its reliability, the principal possibility of an integrated approach to determine the effect on the structural parameters that determine reliability in the course of one series of experiments of both the influence of operating modes and engine starts, as well as the possibility of determining the influence and extreme values of factors is shown for reliability.

Thus, the calculation of the values of one or another indicator enables to obtain the final values of the components of reliability (technical readiness). Indicators enables to determine the variability of factors affecting the components of reliability (technical readiness).

Introduction. Over the past two years, there has been a violation of established market relations between end users of spare parts and suppliers. This led, on the one hand, to a significant increase in the cost of automotive components, and, on the other, to a reorientation of the market to new alternative manufacturers and suppliers. The main purpose of the work was a statistical assessment of the reliability indicators of the most expensive suspension element – the McPherson suspension strut, in the conditions of replacing the original struts with analogues available on the market.

Methods. The study of the operational reliability of systems, components and assemblies of M1 cars was conducted in a dealership during 2022-2023. The study mainly involved cars with a sedan body and a McPherson front suspension. At the same time, the reason for contacting the service, the mileage of the car, as well as the types of work performed were recorded in each work order. The experimental data were processed using MSExcel and MatLab software from MathWorks.

Resultsand conclusions. The conducted research allowed us to conclude that the appeals on the suspension of the car are almost twice as high as other appeals. The most expensive elements – the front shock struts, account for up to a third of all suspension failures. To assess the reliability indicators of alternative racks, the failure distribution law (normal), the probability of failure and uptime are determined, and the parameters of the distribution law are determined: mathematical expectation, standard deviation and coefficient of variation. It was found that the resource of the rear shock absorbers is at least 30% more, and there are significantly fewer calls at the service station. Thus, the operation of a car with racks from alternative manufacturers is quite reasonable, despite the fact that the resource of racks from alternative manufacturers is usually lower than that of the original brands.

Introduction. The purpose of the work is to study the causes of corrosion destruction of bus bodies of the enterprise. In the course of work, it was revealed that the main causes of intensive corrosion destruction of bus bodies are insufficiently high corrosion resistance of metals used in the manufacture of the body frame. The main places of occurrence of foci of corrosion of the body are: wheel arches; rear and lower parts of the bus, which are more susceptible to adverse road conditions; the upper and lower parts of the window openings in case of violation of the tightness of the seal. In the course of the study, initial data were obtained to determine the conditions and factors determining condensation on the cooled surfaces of bus bodies entering the indoor parking area; a set of organizational and technical measures aimed at reducing the intensity of corrosion wear of the company’s vehicle bodies was developed.

Materials and methods. The results of observations of changes in the technical condition of bus bodies, parameters of their maintenance conditions were used, methods of a priori ranking of factors and classification were used. The results and recommendations on the technical operation of bus bodies are described.

Results. As intermediate results of the conducted research, the data on the influence of the technical condition of bus bodies on the indicators of technical operation were obtained, which make it possible to justify the modes of maintenance and storage of motor vehicles. The data obtained make it possible to simulate the processes affecting the technical condition of bus bodies, which is the basis for the development of optimization measures.

Discussion. It is noted that the approach implemented during the study enables to establish a set of factors affecting the technical condition of bus bodies, and to determine the consequences of premature achievement of the limit state by the elements of the load-bearing structure.

Conclusion. As a generalizing conclusion, it is noted that the practical implementation of the developed methodology ensures the development and implementation of sound measures to increase their durability in the practical activities of road transport enterprises.

Introduction. In recent days, the resources of a construction project (СP) are limited; therefore, the main tasks of managing the resource supply of construction production (RSСP) are optimal planning of resources and management of material and technical support. This includes managing the resources, supply, inventory management and distribution of resources by type of construction and installation work (CIW).

Materials and methods. For a systematic analysis of the functioning of a construction project, organizational and technological subsystems are identified that have the greatest impact on the quality and reliability of construction systems. These include construction scheduling, resource support for construction and estimates that determine the cost characteristics of construction production.

Scientific novelty. As a criterion for determining the effectiveness of the construction process, the article proposes to use the organizational and technological reliability (OTR) of complex development, taking into account resource supply. The article examines the factors influencing this criterion, as well as determines the indicators of factors and the interval values of the risk assessment of OTR. The values of the OTR indicator are obtained, which is the probability of completing the project on time, and the classification of factors affecting OTR is supplemented.

Results. Contractors and developers provide construction facilities with all necessary resources according to the technological sequence of production of the CIW, established calendar plans and construction schedules. The organisation of complete supplies of resources through enterprises and divisions of production and technological equipment, as well as production and acquisition bases will provide for the redistribution of necessary resources to fulfill the production program between the construction sites of complex development.The novelty of the study lies in the modelling of the organizational and technological reliability of complex development, taking into account the risks of resource supply.

Discussion and conclusion. To ensure successful resource provision, it is necessary to take into account the risks and take into account, within the framework of information programming, the organizational and technological reliability of the technological processes of the construction project, taking into account the specific conditions and factors of the implementation of the integrated development project.

Introduction. Technological features of road construction require compliance with the requirements for road building materials in terms of physical and mechanical properties and performance characteristics. Control of structure formation processes in cement composite systems can be carried out by various methods and approaches, including choosing the optimal composition, adding special additives, regulating hydration conditions and using special processing methods. This makes it possible to improve the properties and characteristics of conglomerate materials, as well as eliminate or slow down the destruction of their structures. The purpose of this article is to develop composite binders for road use.

Main part. It has been established that in composite binders with the replacement of 50% of Portland cement with waste from wet magnetic separation of ferruginous quartzites with an identified rational specific surface of 500 m2/kg, the activity remains practically at the same level as in the control additive-free compositions, which allows us to recommend this type of binder for development of concrete compositions for road construction.

Conclusions. The addition of the identified rational content of the superplasticizer PFM-NLC (0.6 wt. %) to the co-milled Portland cement-MMC waste system made it possible to create a wide range of composite binders with setting times from 3 minutes. 5 sec. (start) up to 6 min. 35 sec. (end), bending activity up to 9.3 MPa and compression activity 60.7 MPa (with a ratio of bending activity to compression activity of up to 0.16).