Soil Classification and Properties - Multiple Choice Questions

The Atterberg limits are used primarily to classify what type of soil?

• Coarse-grained soils

• Fine-grained soils

• Organic soils only

• Gravelly soils

The water content at which soil changes from a plastic to a liquid state is called the:

• Plastic Limit

• Shrinkage Limit

• Liquid Limit

• Flow Limit

Which instrument is used to determine the Liquid Limit of soil?

• Proctor compaction mold

• Casagrande apparatus

• Sieve shaker

• Hydrometer

The Plasticity Index (PI) is computed as:

• PI = LL + PL

• PI = LL − PL

• PI = LL ÷ PL

• PI = LL × PL

If a soil has LL = 60 and PL = 30, what is its PI?

• 90

• 30

• 15

• 45

Liquidity Index (LI) is used to determine:

• Shear strength of coarse soils

• Soil consistency in its natural state

• Specific gravity of solids

• Grain size distribution

A soil with LI = 1.2 behaves as a:

• Brittle solid

• Plastic material

• Viscous liquid

• Semi-solid

In AASHTO classification, the poorest subgrade materials belong to:

• A-1

• A-3

• A-7

• A-4

The Group Index (GI) formula is used to evaluate:

• Plasticity of coarse soils

• Subgrade quality

• Grain size distribution

• Shear strength

Which of the following is not used in the AASHTO soil classification system?

• Liquid Limit

• Plasticity Index

• Specific Gravity

• Sieve Analysis