Theoretical studies of forest machines with a tracked mover on slopes

In many countries around the world quite large reserves of forest resources are located on mountain slopes. Logging operations in mountainous areas significantly reduce productivity and increase risks for people and machinery. In many industrialized countries of the world machine logging methods dominate including harvesting operations on mountain slopes. Wheeled forest machines operating on mountain slopes are primarily equipped with special tracks. Ecosystems of mountainous forests are very vulnerable and violation of standard operations might result in excessive negative impact on soil, water and wind erosion processes. Especially dangerous for forest ecosystems on slopes is the process of rut formation under the influence of forest machine track driver. It is the track ruts that are concentrators of water and wind erosion. Besides, exceeding the load bearing capacity of the soil might lead to landslides and sliding of the machine down the slope. The article presents theoretical substantiation of permissible average pressure of the forest machine mover on a slope when the depth of the formed rut is limited. The authors present new dependences allowing in practice, without iterations, to calculate: the bearing capacity of the soil under the influence of the track mover, depending on the physical and mechanical properties of the soil. They take into account the angle of the slope; the depth of the rut formed under the influence of the track mover of the forest machine operating on the slope; admissible average pressure of a track vehicle on the subsoil, limited by the depth of the rut formed; coefficient of resistance to movement of a track vehicle moving along a slope; coefficient of traction of a track vehicle with the subsoil surface taking into account sliced subsoil weakening.