6.4. Soil classification using group symbols

Try these first

1. 1.

   Define fine-grained soils.

   Hint

   Think about particle sizes.

2. 2.

   What does the plasticity index indicate?

   Hint

   Consider how soil behaves under different conditions.

3. 3.

   What indicates a high plasticity soil?

   • Clay with PI > 50
   • Clay with PI < 35
   • Silt with PI = 0

   Hint

   Consider the definitions of PI.

4. 4.

   The liquidity index of a soil that is soft falls between which values?

   • 0.5 - 0.75
   • 0.75 - 1
   • 0 - 0.25

   Hint

   Refer to liquidity index classifications.

5. 5.

   Given a soil with 60% clay, liquid limit of 40%, and a plastic limit of 25%, classify the soil and calculate its liquidity index.

   Hint

   Ensure you compute the plasticity index first.

6. 6.

   If a construction site has soils classified as 'GW', what does this indicate about the gravel's properties?

   Hint

   Think about the implications of grading in soil structure.