Resumen
The article presents the efficiency of application of cohesive soil dewatering for increasing its resistance to shearing, which influences the mass stability of flysch rock. Studies of the typical soil constituting the contact layer initiating the sliding of existing Carpathian flysch landslides were conducted. This aspect was examined because the water content of this soil decides its ability to form a sliding surface of the landslide block soil. The soil was subjected to changes in water content by dewatering with different methods. The influence of dewatering by self-acting gravitational outflow was examined and was additionally aided by two selected methods: electrokinetic phenomena and vacuum treatment. The model study conducted demonstrates the influence of the abovementioned dewatering methods on increasing the strength parameter of the soil at the contact layer in which sliding surfaces can be created. The paper also demonstrates the degree to which the application of the vacuum and electrokinetic treatment caused by DC current voltage influences the draining, decrease of plasticity, and increase of soil shear stress resistance. The application conditions and increase in effectiveness due to the application of the studied methods were determined. The proposed methods allowed for the strengthening of slopes for two exemplary landslides which formed in the area of occurrence of the Carpathian flysch.