How can cohesive soil be characterized in terms of moisture?

Cohesive soil is characterized by its ability to retain water and maintain strength when moisture is present. When submerged, cohesive soils, such as clay, can still show significant cohesion because the water molecules are absorbed between the soil particles, creating an adhesive effect. This characteristic helps the soil hold its structure and provides resistance to shear forces, which is particularly important in construction and excavation activities.

Understanding cohesive soil's behavior under different moisture conditions is crucial for excavation operators. For example, if they encounter submerged cohesive soils, they need to recognize that while the soil may be saturated, it still retains some strength and stability, different from granular soils, which can easily become unstable when wet. This knowledge is essential in ensuring safe excavation practices and preventing collapse or instability.