Interaction of wheeled forestry machines with non-cohesive soil

Logging equipment operates in a wide range of soil conditions including waterlogged boggy grounds with low-load-bearing capacity. Small wheeled forest machines may be used for skidding in such conditions. Their use may significantly reduce the negative impact of skidding on forest ecosystems that is manifested in forest soil compaction and rutting, as well as in harming trees' root system. Until now the issues of interaction between a wheeled drive of a small-sized forest machine and the ground surface have not been clarified as the research of a skidding machine impact on the ground has been done mainly for heavy machines. Yet the laws of motion presuppose a significant impact of the wheeled drive's geometric parameters on the ground deformation development Thus, the results of previous work may not be used to justify the parameters of skidding by small machines. In addition, waterlogged weak soils have specific physical and mechanical properties and their relationships and features of the development of arising stresses. These circumstances require further research to complement the scientific picture of the interaction between small-sized wheeled forestry machines and soils. We believe that the results of our research will be the basis for optimizing the parameters of the skidding process using such equipment, as well as improving the parameters of wheeled forest machines. The article presents an analysis of the physical and mechanical properties of soils as surfaces for skidding machines movement and approaches to assess the parameters of the interaction between a wheeled machine and the soil.