Definitions of the bentonite filtration coefficient in the logon deposit in the fergana valley

In the practice of hydraulic engineering, anti-seepage devices made of clay (hereinafter we will use this term as bentonite) soils (depressions, screens, cores, etc.) are widespread. When designing them, it is very important to correctly assess the permeability of the soil. Overestimation of this value leads to excesses in design and waste of material resources, and underestimation - to higher filtration losses. The latter is especially unpleasant for the case of shielding industrial waste storage facilities containing hazardous chemicals, the migration of which in greater than anticipated quantities can cause pollution of the surrounding area and to exclude it from economic use for a long time. The water permeability of soils is quantified by the value of the filtration coefficient. At present, the determination of the filtration coefficient of bentonite is often carried out on the basis of the results of relatively short-term (not more than one month) experiments, which may cause an undefined underestimation of their permeability. With a large area of industrial waste storage facilities (tens and hundreds of hectares) and a significant service life, an underestimation of the filtration coefficient even by one order of magnitude is fraught with significant errors in predicting filtration losses with all the ensuing consequences. Carrying out these studies is necessary, since there are no clear indications in the literature on the most expedient method for determining the filtration coefficient of low-permeability bentonite. Moreover, some authors even express doubts about the possibility of determining it directly, in connection with which they recommend calculating this important soil characteristic indirectly using data from other test methods.