ABSTRACT
Example 4. 11 In a falling head permeameter, the sample used is 20 cm long having a cross-sectional area of 24 cm2• Calculate the time required for a drop of head from 25 to 12 cm if the crosssectional area of the stand pipe is 2 cm2• The salnple of soil is made of three layers. The thickness of the first layer from the top is 8 cm and has a value of k 1 =2 X 10-4 cm/sec, the second layer of thickness 8 cm has k2 = 5 x 10-4 cm/sec and the bottom layer of thickness 4 cm has k3 = 7 x 10-4 cm/sec. Assume that the flow is taking place perpendicular to the layers (Fig. Ex. 4.11).
