Introduction. The article raises the problems associated with electrohydraulic drilling destruction of oversized monolithic objects, which are found, in particular, on the territory of construction works. At the moment, there is no assessment of the technology effectiveness, which means that methods are needed to justify the optimal discharge mode and its reproducibility in industrial equipment.

   The purpose of the article is substantiation of optimal energy parameters for destructing monolithic objects by using electrohydraulic drilling method.

   Materials and methods. The analysis of factors contributing to electrohydraulic fracture of monolithic objects was carried out and the most significant ones were identified. It is proposed to characterize the discharge mode with a set of parameters related to the transitional processes at the moments of conductor destruction, the discharge duration and the amount of energy input. Сalculation of the parameters has been presented in this paper.

   Results and discussions. Based on the identified active factors, a stand for registration the electrohydraulic effect has been developed. Parameters for ensuring reproducibility of the discharge mode are derived depending on the change in the discharge circuit inductance. Practical implications are proposed based on data analysis.

   Conclusion. The research findings advance a simple experiment planning to evaluate technology effectiveness. The article will be of interest to researchers in the field of electrohydraulic and electropulse technologies, and practitioners involved in clearing territories and removing monolithic objects.

   Introduction. The main element of the subway escalator is a supporting metal structure, on which all elements, components and assemblies are installed, ensuring its functioning as a continuous lifting machine. The supporting metal structure must withstand not only its own weight and the total weight of the components and mechanisms attached to it, but also provide resistance to dynamic loads arising during their operation. The implementation of comprehensive diagnostic measures aimed at analyzing the level of wear and determining the residual life of escalator metal structures encounters a number of difficulties associated with high demands on time, material and financial costs, as well as disruption of the public transport system.

   The main goal of this study is to optimize the timing for recording the initial data obtained during the diagnostic examination of escalator metal structures with an obvious reduction in the duration of their forced downtime.

   Materials and methods. During the research process, data from a comprehensive survey of escalators based on the State Unitary Enterprise “St. Petersburg Metro” in the amount of 218 pieces in the period from 2005 to 2019 were used, design documentation, statistical methods and mathematical modeling methods were used.

   Results. The use of a mathematical model and the principle of rationalization can significantly reduce the time and, consequently, other costs in determining the corrosion effect.

   Conclusion. The use of the proposed approach to the rational allocation of time periods for conducting diagnostic examinations of operated escalator metal structures facilitates the preventive final forecast estimate of the magnitude of the corrosion effect while reducing the total period of control measures by 38%. The principle of rationalization can also be used in the implementation of accelerated tests for corrosion resistance of materials.

   Introduction. Hydrodynamic pressure plays an essential role in the operation of transport and technological machines used in flooded areas for recovery and emergency actions. The study of this influence has a great relevance due to the necessity of improving the work efficiency and safety in water environment. Hydrodynamic pressure can cause changes in machine operation and influence on its maneuverability and stability. Understanding of these processes allows to develop more effective methods to prevent the negative impact consequences of the water on the machine performances, let us evaluate the safe conditions of their use.

   The aim of the study of hydrodynamic pressure effect on transport and technological machine movement to wade through the water impediment, using the example of an all-wheel drive excavator-loader with equal-sized wheels, is to determine the critical values of the water barrier parameters, which ensure effective and safe overcoming of water obstacles by this type of vehicle.

   Materials and methods. Theoretical studies related to the influence of water flow on the movement of self-propelled wheeled machines were used for the analysis. Mathematical modelling of rectilinear movement of backhoe-loader through the water barrier of different depth and with different flow velocity was carried out. Transverse (frontal) hydrodynamic resistance, longitudinal (lateral) hydrodynamic pressure and standard reactions on the machine wheels were taken as the main parameters under study.

   Results. Mathematical relationships were derived to determine the standard reactions on the front and rear axles of the excavator-loader under the influence of transverse hydrodynamic resistance in standing water, normal reactions on the left and right sides of the machine under the influence of longitudinal hydrodynamic pressure on the stationary and moving machine, graphical relations of normal reactions of the wheels depending on the depth of the water stream were deduced.

   Discussion and conclusion. The presence of unfavorable factors of the water environment effecting the movement of transport and technological machines through the water obstacle provides the basis for the development of a methodology for determining the maximum flooding parameters at which machines can perform work safely and effectively in flooded areas. The study of the influence of hydrodynamic pressure on transport and technological machines is an important task aimed at solving this problem. The obtained results will help to develop machine building techniques and technologies for operation in conditions with increased hydrodynamic pressure, which contributes to the development of industries related to the operation of land transport and technological machines in the aquatic environment.

Introduction. When the vehicle slows down, particularly on slippery surfaces, stability of the electromechanical drive system movement can be reduced, which is accompanied by high self-excited vibrations. These vibrations occur when the sliding speed increases and the friction force decreases. At the same time, the dynamic load on the drive system increases sharply, which can lead to its failure. Thus, the development of methods for suppressing self-excited vibrations is an urgent task.

The purpose of the study is to test the operability and effectiveness of the method for suppressing self-excited vibrations in the electromechanical wheel drive system during braking with the use of methods of field experiments.

Materials and methods. The study of the efficiency and effectiveness of the algorithm was based on field experiments.

Results. Based on field experiment method, the efficiency and effectiveness of the algorithm for suppressing self-excited vibrations during deceleration has been determined, which allows for six-fold reduction in maximum amplitudes and 3-3,5-fold reduction in averaged amplitudes, while excluding changes in the moment sign during vehicle intense deceleration.

Conclusion. The algorithm of suppressing self-excited vibrations can be recommended for application in developing vehicle deceleration control systems

   Introduction. Accidents in cities and outside populated areas have their own characteristics, which have been studied in various works. However, changes in the characteristics of traffic, pedestrian flows, and those of the street and road environment structure usually are not observed on crossing the city boundaries. Calculations show that it is in the suburban zone that the highest accident density is estimated, as well as a high proportion of accident-
hazardous areas. Besides, there has been an increase in the suburbanization process, which leads to the growth of suburban areas. In this regard, assessing the impact of various factors on accidents within the suburban boundaries is an urgent research task.

   The aim of the study is to investigate the influence of environmental factors on accidents in suburban areas (the city of Barnaul is observed as an example).

   Materials and methods. In this study the suburban zone of Barnaul was considered as an example, the boundaries of the zone being defined according to the transport methodology. The empirical basis of the work was data on accidents that were recorded for the sections of federal highways within the boundaries of the suburban zone in the period from 2018 to 2023. For each accident from the sample, the period of day and weather conditions (air temperature, precipitation rate and wind speed) were determined. The relative risk theory was used to assess the influence of the factors selected.

   Conclusions. The study identified the distinctive features of accidents in suburban areas in comparison with those of suburban and urban road conditions. The influence of the group of key external factors was also assessed: periods of the day and weather conditions. Among the former, day, civil, navigational, astronomical twilight and night periods were distinguished. As for the latter, air temperature, precipitation rate and wind speed were analyzed.

   Limitations of the study/implications for future research. The results of the study can be used in further comprehensive research of accidents in suburban areas of large cities.

   Practical implications. The identified features of accidents and the dependence of the relative risk of accidents in the suburban area on external factors can be used for preventive measures development, as well as in the development of intelligent transport systems.

   Originality. For the first time, the dependences of the relative risk of accidents in the suburban area as a result of a group of key environmental factors (period of the day and weather conditions) were determined.

   Introduction. The complicated system of characteristic interaction between the Driver-Car-Road-Environment (DCRE) is the research subject for the scientists around the world. If we explain the patterns of phenomena present during road accidents, we will be able to model some transport processes. To do this, we need to consider a large number of characteristics, dividing them into static and dynamic. Particular attention is paid to the latter, due to the instability of the features. This category includes traffic flow intensity and weather conditions. There are a lot of methods for increasing the accuracy of predictive models, but this method has been used for the first time. Logical
and statistical validity of the selection automation of interval rages are the main feature of this method. This is necessary not only for grouping features, but also for increasing their value in a joint analysis. For example, for the intensity of traffic flows the index number can be 100 vehicles/hour (0-100, 101-200, 201-300, etc.), but it will not be effective from a prognostic point of view for the temperature interval index of 5°C (-25 - -20, -19 -15, -14 - 10,
etc.).

   Accordingly, the goal of the work was to determine the effective forecasting of the interval’s width of traffic flow intensity (dependent feature) and weather conditions (independent features).

   Materials and methods. This work is a continuation of a large project on improving road traffic safety, in which similar studies have already been conducted to determine the effective interval coefficients using Spearman’s rank correlation. The values at which temperature regimes (air, soil and dew point) best describe the intensity of the traffic flow were established. For a comprehensive characterization, additional analysis was necessary to conduct of the remaining independent features. New algorithmic structures were created using the Python programming language, in which the established feature interval ranges were sequentially compared in such a way as to process all possible combinations. Each result was subjected to correlation analysis, and the probability of error was calculated.

   Results. As a result of the experimental selection of interval ranges, the most effective of them were determined. The selection criterion was the subsequent correlation analysis. The coefficient values greater than 0.7 or less than -0.7 were accepted. The probability of error was also calculated, and values less than 0.05 were accepted. Thus, a large number of combinations were obtained that meet the necessary conditions. Further, for each feature, the interval width was selected at which it is more often intersected with others, and in the case of the same number of intersections, it is the smallest of them.

   Conclusion. As a result, effective interval widths were determined in which the investigated features had been analyzed. This study in subsequent works contributed to the high-quality training of the model using the deep learning method. Thanks to this research, a program to predict the intensity of the traffic flow, depending on weather conditions with using neural networks was created.

   Introduction. Modern wheeled vehicles are equipped with plug-in all-wheel drive control systems that increase their trafficability, stability and controllability. A good example is the AWD (All-wheel drive) system, which provides the highest efficiency of a plug-in drive compared to a permanent all-wheel drive. In order to ensure and maintain the efficiency and safety of vehicles with plug-in all-wheel drive control systems, it is necessary to investigate their functioning during manufacture and operation stages. Road testing methods are the most widespread methods for testing the systems under consideration. However they are not always feasible in the conditions of enterprises which provide testing and examination of vehicles, as well as in the conditions of service stations, service centers and other organizations of the automotive industry.

   Materials and methods. For the purpose of analytical research, a developed set of mathematical models containing the “ Vehicles “ and the “Stand” subsystems models was used. The description of the models is completed with the software package “Universal mechanism-9”. Experimental studies of operation of the vehicle with an automated AWD system were carried out on a full-support multifunctional stand with IRNIT running drums. The Volvo S60 25T AWD automobile with Haldex clutch of II generation was used as a research object.

   Results and discussion. In the course of analytical and experimental studies, the results of investigating vehicle operation were obtained by simulating acceleration with the slipping of the driving wheels of both the front and rear axles: the traction force on the driving wheels and the wheel speed.

   Conclusion. The results of this analytical research and their correspondence to the results of experimental study show the possibility of conducting qualitative and quantitative testing of automobiles with plug-in all-wheel drive control systems on roller test benches. The use of a complex of mathematical models will further allow for the development of unique bench methods and equipment to carry out research on the operational properties of modern vehicles.

   Introduction. Currently, when designing road pavements taking into account soil shear displacement, shear stresses from temporary and permanent loads are calculated at different values of internal friction angle. Consequently, in terms of soil shear displacement while designing road pavements, stresses applied along two different sites are considered, which is an error and requires correction.

   Materials and methods. A model for predicting accumulated residual deformation has been developed, which allows for determining the value of the maximum principal stress at which the residual deformation reaches its limit value, given that values of the minimum principal stress and the number of applied loads are known. The values of principal stresses being taken into account, the adhesion and the angle of internal friction are calculated for the number of loads considered in the deformation calculation.

   Results. The calculation of shear resistance and resistance to universal tension parameters was performed by applying the proposed model and the Barksdale-Kazarnovsky model for calculating the accumulated residual deformation. The calculation results have been compared.

   Conclusions. The obtained results allow for designing surfaces of roads of low traffic intensity based on the criterion of resistance to soil shear displacement.

   Introduction. The complex influence of dynamic loads, climatic factors, and aggressive environments is the driver of premature deformation of asphalt concrete pavements. The main types of failure are: plastic rutting deformations occurring at high temperatures above zero; fatigue cracks in the pavement caused by repeated loads; low-temperature transverse cracks occurring in the area with temperatures below zero while pavement cooling. According to modern concepts, the contribution of the binder to the formation of the described defects reaches 90–100 %. However, bitumen loses its original properties, interacting with mineral powder and forming an asphalt binder, which acts as a binder in asphalt concrete. Therefore, it is advisable to predict the behavior of asphalt concrete in a wide range of temperatures, and especially in low-temperature part, relying not on the bitumen binder, but on the asphalt binder.

   Materials and methods. Experimental laboratory studies of materials were carried out in accordance with GOST 33133–2014, GOST R 58400.1–2019, GOST 32761–2014, GOST 58401.1–2019, GOST R 58400.8–2019, GOST R 58400.11–2019. The objects of study were bitumen filled with mineral powders from limestone and dust from electric filters of an asphalt concrete plant.

   Results. Significant changes in the properties of the original bitumen were revealed under the influence of varying degrees of filling with mineral powder from limestone and dust from electric filters. It was shown that filling the binder with mineral powder (dust) in the maximum permissible concentration limit changes the PG (X) brand parameter by three positions from 64 °C to 82 °C. More fundamental data were obtained for the low-temperature stability of samples with a collapse of the parameter (± Y) from -34 °C to -22 °C. By identifying the parameters responsible for low-temperature cracking of the system at the binder level of asphalt, it is possible to scale the knowledge to asphalt concretes.

   Introduction. The modulus of elasticity refers to one of the main physical and mechanical characteristics of reinforced local grounds. Deformations of soils and building materials are usually described by Hooke’s law. The main laboratory testing methods include applying of uniaxial compression, triaxial compression, rigid stamp technics. Determining the modulus of elasticity is a complex, time-consuming and labor-intensive test. There are empirical models that describe the relationship between the modulus of elasticity and various parameters and characteristics (compressive strength, binder content in the mixture, etc.). However, these models are mainly developed for stabilized soils and for crushed stone reinforced with Portland cement.

   Methods and materials. To determine the pattern of change in the modulus of soils’ elasticity reinforced with inorganic binding materials from compressive strength, studies were conducted on samples of various soils strengthened with Portland cement and lime. Existing methods specified in the regulatory and technical documentation were used to produce the samples.

   Results. Based on the performed research, two empirical models were developed that reflect the dependence of the elastic modulus values on the compressive strength values of soils reinforced with Portland cement and lime.

   Discussion and conclusions. Existing testing methods of the elastic modulus are lengthy and labor-intensive. The developed empirical models allow us to obtain approximate values of the elastic modulus from the values of compressive strength of soil samples reinforced with Portland cement and lime.