Permeability Tests

Constant Head
 Permeability Test

Constant Head Permeability
Test Diagram

Falling Head Permeability
 Test Diagram

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Permeability tests are conducted to estimate the coefficient of permeability (k). This will be used in pumping and dewatering design.

Constant Head Permeability Test
The soil sample is placed in a cylinder and supported by a coarse filter or a wire mesh. The volume of water flowing through the specimen under a constant total head is measured per unit time. This can later be related, through calculations, to permeability.

Falling Head Permeability Test
This method is more appropriate for fine-grained soils. A coarse filter is placed above and below the sample and a standpipe is connected to the top of the cylinder. Water drains into a constant head reservoir at the bottom, the falling water level in the standpipe is measured at time intervals. This is later related, through calculations, to permeability.