Determine the important factors that affect the permeability of a soil.
A permeameter of 8.2 cm diameter having a sample of soil of length 35 cm. It can be used either for constant head or falling head tests. The standpipe used for the latter has a diameter of 2.5 cm. In the constant head test the loss of head was 116 cm calculated on a length of 25 cm when the rate of flow was 2.73 ml/s. Determine the coefficient of permeability of the soil.
If a falling head test were then made on the same soil, how much time would be taken for the head to fall from 150 to 100 cm ?