UNIVERSAL METHOD FOR CALCULATING WATER PERMEABILITY OF ANTIFILTRATION LININGS WITH POLYMER GEOMEMBRANES

There is considered a method for calculating water permeability of the main types of channel linings using geosynthetic materials – concrete film and soil film with polymer geomembrane and geotextile. During a long-term operation of irrigation channels it is necessary to carry out a quantitative assessment of water permeability of the linings, the results of which find filtration losses and determine the calculated efficiency. Modern anti-filtration channel linings made of geosynthetic materials can provide a high technical efficiency and durability of the lining. Based on the previously obtained theoretical solutions through single damages, a universal method has been developed that can be used to calculate water permeability of the main types of linings using geomembranes (concrete fi lm and soil fi lm). There are given calculation schemes through soil film and concretefilm lining and calculation dependences for the main calculation cases in the presence of cracks and holes in the screen on a highly permeable base and taking into account the influence of the permeability of the underlying base. The influence of the base permeability is taken into account in the calculations by the piezometric pressure h1at the damage place of to the geomembrane screen which is a residual pressure between the lining and soil base. The residual pressure can have both a positive sign under the excess pressure and a negative sign under formation of vacuum pressure. The calculation formulasfor determining the piezo-metric pressure at the place of damage are found using the equation of continuity of the filtration flow passing through defects and damages of the lining. Based on the developed method for calculating water permeability an example of calculation is considered which indicates a high efficiency of linings using geomembranes (concrete film and soil film) and for the concrete lining the condition of efficiency is not fulfilled.

Экспериментальное исследование влияния добавки наночастиц на фильтрационные свойства микросуспензии

We have experimentally studied the filtration of microsuspensions with added silica (Aerosil) nanoparticles via porous media of variable permeability. The concentration of added nanoparticles in solution was changed from 0.25 to 4 mass % and their average size was varied from 5 to 100 nm. Dependences of the filtration losses of microsuspension on the concentration and size of nanoparticles and the permeability of porous medium variable have been determined.