VERIFYING THE SUBGRADE SOIL CHARACTERISTICS OF FLOOD BANK.

Twenty years after finishing the dam Čunovo on river Danube about 15 km beneath Bratislava were after regular controls gradually exclude from system some observation boreholes. There were realised new investigation boreholes. The main reason of these boreholes was verification of the soil characteristics in depth where the periodical changing of water in Danube and in reservoir had negative influence on the permeability characteristics. One of the most important factors of safety is filtration stability of granular soils. In boreholes was periodically measured the velocity of groundwater and from results analysed the safety of soils below the protective dam. Results after 2010 showed that the filtration stability of soils was decreased. Several theoretical criteria of filtration stability were applied for validation of experimental results. The paper will put the focus on field and laboratory analysing of the soil investigation. Comprehensive assessment of theoretical knowledge relating to the soil degradation by hydrodynamic influence of groundwater and results of field measurement was recommended preparing the construction of sealing cut-of-wall interferes in depth at minimum 20 m below the ground surface. [ABSTRACT FROM AUTHOR]