Investigation of stress-strain state of soil under a tracked forest machine

The article considers the urgent problem of increasing the cross-country ability of forestry machines by taking soil mechanics into account. The characteristics of soil conditions, as well as the dependence of the soil impact of a tracked forestry machine on the depth and slope of the terrain in the forested areas of the Russian Federation are presented. This study is focused on determining the nature of the stress and strain field in the soil under the forest machine tracks to take into account the data on the impact of vegetation in the area of logging and transport operations since the diversity of the soil structure and its visco-elastic-plastic properties provides only a qualitative explanation of the situation. The problem under consideration belongs to the class of plane deformation problems. The article provides formulas for the approximate determination of stresses in a soil mass from a band load. It was found that with the increasing distance from the center of the loaded surface and with the increasing depth, the vertical pressures decrease. By horizontal sections of isobars, one can trace the patterns of pressure changes across the width of the soil mass. And the general pattern is that when the depth of the impact increases, the pressure intensity decreases, and the zone of their action increases in width. A stress field was also obtained in the zone of the forest machine impact on the soil suitable for constructing a mathematical model.The problem under consideration belongs to the class of plane deformation problems. This is due to the structure of the region and the boundary conditions. All planes perpendicular to the y axis are equal in this problem. Therefore, all the sought-for functions are independent of the y coordinate, and therefore it suffices to consider only one of such planes, for example, the xOz plane. The component ν of the displacement vector along the y axis is identically equal to zero, however, the normal stress σy is nonzero. The article provides formulas for the approximate determination of stresses in a soil mass from a band load. As a result of the study, it was found that with increasing distance from the center of the loaded surface and with increasing depth, the vertical pressures decrease. By horizontal sections of isobars, one can trace the patterns of pressure changes across the width of the soil mass. And the general pattern is that when the depth of the impact increases, the pressure intensity decreases, and the zone of their action increases in width. A stress field was also obtained in the zone of the forest machine impact on the soil suitable for constructing a mathematical model.