Geotechnical substantiation of the operability of skidding drags and technological corridors on the slopes of thawing soils during the operation of forest machines with wheeled and semi-tracked propulsion

In the Russian Federation a significant part of the forest fund is located on permafrost. Many regions of Russia have large reserves of ripe and over-mature operational forests, and a significant part of these reserves is located in hard-to-reach places. Currently, the overwhelming volume of wood harvesting in Russia is performed by using modern machine complexes mainly including wheeled forestry machines of various configuration and purposes. At the same time the problem of the negative impact of wheeled forest machines and skidding systems based on them becomes even more acute since the ecosystems of mountain forests and forests on the slopes of hills are among the most vulnerable ones due to water and wind erosion. To reduce the negative impact of forest machinery propellers on soils semi-tracked vehicles are often used because of their significantly larger contact surface and a greater traction force in difficult conditions. The article shows that each slope as a unique geotechnical object that features its own geometric parameters and actual data including the capacity of the thawing soil bearing surface and permafrost zone edge should be classified taking into account the variety of skidder movement parameters, the technological properties of soils and the criterion of the extraction road operability. The development of such a classification should be based on up-to-date hydrogeological and geomechanical data on the state of the soils composing the slope area. The presented studies expand the understanding of the technological requirements for ensuring the extraction road operability on the slopes with thawing soils, thus contributing to more efficient use of logging technology in difficult seasonal and climatic conditions.