A soil has liquid limit of 60%, plastic limit of 35%, shrinkage limit of 20% and it has a natural moisture content of 50%. The liquidity index of this soil is
- A1.50
- B1.25
- C0.60Correct
- D0.40
Solution
Concept
Liquidity index
Formula
LI = (w − PL) / PI
Step-by-step solution
1. PI = 60 − 35 = 25. 2. LI = (50 − 35) / 25 = 0.6.
Explanation
The liquidity index shows the position of the natural water content between the plastic and liquid limits. The shrinkage limit is not required for this calculation.
Shortcut
LI = (w − PL) / (LL − PL).
Common mistake
Using the shrinkage limit in the formula.
Correct answer: C) 0.60