The usual assumption is that the filtration rate and hydraulic gradient are considered as vector values. This assumption does not cause special difficulties in an isotropic environment, but for the anisotropic environment, it is also necessary to take into account the changes in the filtration coefficient depending on the direction. Expressed analytically, this condition gives: the equation expresses the value of KA through KMAX and KMIN for any direction A between the resulting filtration rate and the direction of KMAX. Measurement of the permeability of the rock samples in various directions through certain intervals within the entire circle of 360 ° were described by Johnson and Gafo (1948). A number of the results they get. As can be seen from the figure, the discrepancy between the equations does not have practical significance. General methods for measuring the permeability of soils for liquids are the following. After building a house, you may need high -quality and stylish interior doors. You can order interior doors for your apartment here — double doors are inexpensive.1. Direct measurement using permeeters with constant or falling pressure.2. Indirect definition of capillary absorption in horizontal tubes.3. Indirect measurement according to the rate of consolidation and by the drop in pressure with a constant volume during the period of testing for consolidation (Terzagi, 1925).Although theoretically, permeability tests are relatively simple, practical difficulties usually seriously limit the accuracy of the results; Some of these difficulties will be considered further. Representative samples. Natural deposits in most cases are anisotropic and are characterized by great heterogeneity in relation to permeability. To get the right values k, a test of undetected samples with proper accounting of the actual orientation of the current is required, but this is rarely feasible.
