What does a well-graded soil contain?

• A. A narrow range of sizes
• B. A variety of sizes
• C. Only fine particles
• D. Homogeneous particle sizes

Answer: (B)

A well-graded soil is characterized by having a variety of particle sizes. This means that the soil contains a mixture of small, medium, and large particles. The presence of multiple sizes allows the smaller particles to fill the voids between larger particles, resulting in a denser and more stable soil structure. Well-graded soils tend to have better drainage and compaction properties, making them ideal for construction and engineering applications.

In contrast, a soil with a narrow range of sizes would not be well-graded and could lead to issues such as poor compaction and drainage. Similarly, soils containing only fine particles or homogeneous particle sizes would lack the necessary variety to achieve the benefits associated with a well-graded soil, such as improved stability and load-bearing capacity. Overall, the diversity in particle sizes is crucial for achieving optimal engineering properties in soils.