Question

The plastic limit of a sensitive clay is 30% the plasticity index is 30% and the natural moisture content is 63%

The liquidity index of this soil is

1. 0.6
2. 1.1
3. 1
4. 0
5. 1.15

Answer 1

Correct Answer - Option 2 : 1.1

Concept:

Liquidity index is defined as the ratio of the difference between the natural water content of a soil and its plastic limit to its plasticity index.

\({I_L} = \frac{{{w_n} - {w_P}}}{{{w_L} - {w_P}}} = \frac{{{w_n} - {w_P}}}{{{I_P}}}\)

where, w_P = water content at plastic limit

w_L = water content at liquid limit

w_n = natural water content

I_P = plasticity index of soil

Calculation:

Given,

w_P = 30%

w_n = 63%

I_P = 30%

Liquidity index (I_L) = \(\frac{{{w_n} - {w_P}}}{{{I_P}}} = \frac{{63 - 30}}{{30}} = 1.1\)