What characterizes cohesionless soils?

• A. Soils with significant clay content
• B. Soils primarily made of gravel and sand
• C. Soils with high water content
• D. Soils that hold together due to cohesion

Answer: (B)

Cohesionless soils are primarily characterized by their composition, which consists mainly of granular materials such as gravel and sand. These types of soils lack the fine particles, like silt and clay, that produce cohesive forces between particles. The absence of these cohesive materials means that the strength and stability of cohesionless soils rely significantly on the interlocking properties of the larger grains rather than bonding through electrostatic or mechanical forces.

Cohesionless soils are typically well-draining and do not hold water as clingily as cohesive soils do. Their behavior under load is largely influenced by factors such as density, grain size distribution, and moisture content rather than cohesive strength. In geotechnical engineering, understanding the characteristics of cohesionless soils is crucial for applications like foundation design and earthwork, as their stability varies significantly based on compaction and moisture conditions.