卷 21, 编号 2 (2024)

One of the key factors in the development of the Russian timber industry is the increase in available timber resources, which should be ensured by the constant expansion of the network and improvement of the quality of timber roads. Well forested areas, as a rule, are significantly removed from the places of extraction and production of traditionally used road-building materials: sand, crushed stone, gravel, crushed stone-sand mixtures, which leads to an increase in the cost of their transportation and the cost of constructing logging roads in general. In these conditions, it is effective to use the technology of strengthened local soils for the construction of logging roads, which ensures high quality and durability of road pavement while reducing the cost of construction and installation work. Considering the high transport loads and weak clay soils at the base of the roadbed that are common in the forest zone, it is advisable to use fiber cement-modified soil for constructing layers of road pavements. On account to the dispersed reinforcement of the cement-soil matrix of the material with fiber distributed throughout its volume, the fiber-cement soil has higher strength indicators, frost resistance and crack resistance of the road pavement structure compared to cement-modified soil. The process of structure formation of fiber cement soil occurs through the interaction of cement stone and fiber, so the study of the dynamics of this material strength gain is relevant. Laboratory studies of physical and mechanical parameters were conducted at 7, 28 and 56 days of strengthening of fiber cement soil. Also, pilot production studies were conducted on the dynamics of increasing the elasticity modulus of fiber cement soil pavement on a trial pavement section of a logging highway. Based on the results obtained from studies of compressive strength and tensile strength during splitting of fiber-cement soil samples, the influence of fiber admixture on the process of structure formation and on the dynamics of the material strength gain was established. During the construction of a trial pavement section of a logging highway, the technical and technological feasibility of fiber cement-soil layers establishment in logging highway pavement structures was proven. The dependence of the actual elastic modulus of the fiber cement-soil pavement on the time of material strength gain, as well as the minimum time period required to achieve the calculated elastic modulus of the road pavement structure of a timber highway, has been traced. The construction of fiber cement-soil layers of road pavements requires a minimum set of road construction equipment and the amount of imported road construction materials, thus significantly reducing the cost of construction and installation work, and also, due to the long service life of road pavements, the cost of logging roads maintenance.

Grinding of feed grain is one of the main operations necessary for the preparation of feed. The proper functioning of the digestive system of animals, their health and productivity depend on the quality of grain grinding. To grind feed grain, most enterprises of the agro-industrial complex use hammer crushers; however, the operating experience has revealed lack of efficacy of their grinding process. In order to increase the efficiency of the feed grain grinding process, the authors propose to use a centrifugal shredder based on a different kinetics with a slightly different process of interaction between the crushed material and active and passive crushing members in comparison with those of hammer crushers. A detailed description is presented and the principle of operation of a centrifugal feed grain shredder is considered. To study the operation of the centrifugal shredder in working environment a production line for feed grain processing was created. The authors present a diagram and a description of the production line operation for feed grain processing in working environment, which includes the following main elements: a feed auger; a centrifugal shredder; an outfeed auger; a mixer; control and regulation devices. The authors describe the experiment conducted in working environment including the sequence and means of control of the selected operating parameters and present formulas to determine the studied parameters, such as: productivity, power consumption, average diameter of crushed particles. The rationale for the choice of the main regime parameters and criteria studied during the experiments is presented. To select the optimal mode of operation of a centrifugal feed grain shredder when grinding barley grain in working environment, an analysis of data obtained during laboratory studies is presented. It was found that with a rotor rotation speed equal to 3500 min-1 and an area of the discharge window of the operational hopper of 0,001458 m2, the greatest productivity of the centrifugal shredder is observed, and in combination with the amount of power intake and the resulting sizes of crushed particles, the best efficiency of the grinding process is achieved. Based on the results of the research conducted in laboratory and working environment, a comparative analysis of the data obtained is presented. The authors conclude that operating a centrifugal shredder at the selected optimal mode and at a rotor speed that is beyond the value necessary for grain destruction is possible. The obtained data analysis indicated the reasons for the discrepancy of the results obtained during experiments in laboratory and working environment.

The article substantiates the optimal technological parameters of the plow combined body used for basic tillage. As part of the rational energy-saving technology of reforestation, the proposed plow body will be included in the design of multifunctional tools that allow for high-quality tillage in uncleared stands. The process of high-quality tillage includes a full turn of a soil layer and its laying next to an open furrow with the highest possible preservation of the layer’s integrity. Experimental studies have been performed to determine the main characteristics of assessing the quality of tillage with the proposed tool, in particular, the rotation of the soil layer and its deformation coefficient, as well as the longitudinal and transverse displacement of the soil mass. The authors determined the dependences of the rotation angle of the soil layer, the coefficient of its deformation and the longitudinal and transverse displacement of the soil mass on three main technological parameters of the tool, such as: the approach angle and the angle of inclination of the disk housing, and the turning angle of the plow moldboard. It has been established that the approach angle has the greatest influence on the above-mentioned characteristics of the plow, the angle of inclination of the disk housing has a less significant effect, and the turning angle of the plow moldboard has a very insignificant effect on the characteristics of the plow. It has been found that in this case, the approach angle and the angle of inclination of the disk housing have a contradictory effect on the treatment process. For example, an increase in the approach angle and a decrease in the angle of inclination of the disk housing increase the turnover of the soil layer while reducing its safety. In this work, the original goal set by the authors has been achieved: to study the process of turnover and deformation of the soil layer by the forest plow body and to determine its optimal parameters that affect high-quality of tillage. Regression models have been obtained that allow determining the optimal technological parameters of the plow combined body, namely: the approach angle 360, the angle of inclination of the disk body 150, the moldboard turning angle 200.

The holding power of a highway is one of the most important indicators for its effective operation. The traffic capacity of the road reduces significantly when this indicator decreases. This is especially true for seasonal highway haul. To preserve the holding power of the highway, it should be properly operated with all negative factors taken into account. Currently, many characteristics have been studied and measures have been proposed to reduce the negative impact on the highway. However, multifactorial modeling should be used in complex road processes. The purpose of this study is to determine the factors affecting the holding power of a principle-type paved highway, as well as their significance. According to the results of the literary analysis, 35 factors were identified for the study. Tentatively each factor was placed into one of the groups: natural-climatic, technological, and operational. The analysis of the factors was based on the results of expert assessments. The experts were engineering and technical workers of road enterprises, employees of the Ministry of Transport of the Krasnoyarsk Territory and representatives of the Department of Highways and Urban Structures of the Siberian Federal University, Russia. A total of 18 people participated in the assessment. When analyzing the estimates, the weighting of each factor was determined. The indicators «Soil moisture» and «Pavement material» had the greatest weight of 9.2 %. It was also possible to identify factors with a weight of more than 0.04. The number of such indicators was six. These factors should be the first ones to take into account when controlling the highway holding power. Besides, 17 out of 35 factors with a weighting index of less than 0.025 were assumed insignificant. In assessing the variance and variation, the consistency of expert opinions was determined to be satisfactory. In general, the research results are consistent with those previously obtained and presented in reputable scientific publications. For further laboratory tests it is necessary to take into account the six most significant factors: soil moisture, pavement material, air temperature and solar radiation, the magnitude of the load on the axle of the vehicle and the tire pressure indicator, the number of repetitions of heavy load application and the interval between these applications, the density of layers of pavement and roadbed.