Summary:

Construction of forest roads on swampy terrains poses many problems and is expensive, therefore the Authors compared the method so far used to achieve road passability owing to the application of rubble with a modern method, where the main element is a geotextile with a track reinforcement of additional fibres. In the presented experiment the geotextile was embedded into the surface structure as a flat layer or as a semi mattress and covered with variously grained sand or crushed granite. Four variants of the surface construction obtained in this way with additionally established reference stretch of the rubble surface were tested using a light weight dynamic deflectometer (LWD) before and after rainfall. The obtained results demonstrated an approximate bearing capacity of the road surface in the tested technologies, clearly exceeding bearing capacity of the reference stretch of road. The rainfall caused a decrease in bearing capacity on all tested sections, however, the greatest decrease of bearing capacity was observed on the reference stretch. The tested technologies do not allow to achieve road surface bearing capacity suitable for the heavy vehicles carrying timber, but they may provide the base layer for this type of roads or form an independent surface on forest technological routes (so called permanent logging routes) used e.g. for logging and hauling of timber.