Write step by step procedure to determine coefficient of permeability of fine grained soil by falling head method in laboratory.

1 Answer

Answer :

This method is suitable for fine grained soil as quantity of water collected through soil mass is very less and cannot be measured accurately

2. The falling head test is used for relatively less permeable soil where the discharge is small.

3. A stand pipe of know cross sectional area “a” is fitted over permeameter and water is allowed to run down.

4. The water level in the stand pipe constantly falls as water flows.

5. Observations are started after steady state of flow has reached.

6. The head at any time instant “t” is equal to the difference of water level in the stand pipe and the bottom tank. 

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