How can moisture content affect granular soils?

Moisture content plays a critical role in the behavior of granular soils, influencing their physical properties and performance. When granular soils, which typically consist of individual particles like sand or gravel, are dry, they tend to lack cohesion, making them more susceptible to crumbling or collapsing under load. This phenomenon is primarily due to the absence of moisture, which can otherwise contribute to both temporary cohesion through surface tension and inter-particle friction when present.

The presence of moisture can create a binding effect among the soil particles. Insufficient moisture can lead to a loose arrangement, where the granular soil easily crumbles apart when disturbed. In contrast, an appropriate amount of moisture can enhance the stability of granular soils by increasing frictional resistance among the particles and preventing them from being overly loose or fragmented.

Options suggesting that moisture increases cohesive strength or allows the soil to be molded might lead to misunderstandings. Granular soils typically do not exhibit significant cohesion even with moisture, as their strength is primarily derived from inter-particle friction rather than cohesive forces. Additionally, while moisture can influence physical properties in various soil types, granular soils lack the plasticity that allows them to be molded like cohesive soils or clays when wet.

Therefore, understanding the relationship between moisture content and the behavior