What information is essential for soil type classification?

• A. Moisture content
• B. Particle size distribution
• C. Shear wave velocity
• D. Consolidation parameters

Answer: (B)

Particle size distribution is fundamental for soil type classification because it provides a detailed breakdown of the different sizes of soil particles present in a sample. This information is crucial in determining the characteristics of the soil, including its classification into groups such as gravel, sand, silt, or clay. The distribution of particle sizes directly influences the soil's behavior, including its permeability, drainage characteristics, and the potential for settlement or compaction.

For instance, soils with larger particles, like gravel and coarse sand, typically have high permeability and low cohesion, while fine-grained soils like clay exhibit high cohesion and low permeability. Accurately classifying the soil based on particle size distribution is vital for engineers when designing foundations, roadbeds, and other structures, as it affects the engineering properties of the material being used.