What indicates that a soil is classified as Type B in the classification system?

The classification of soil types is crucial for understanding how they behave under load and how they should be excavated or supported during construction work. Type B soil, which is characterized by certain properties, includes cohesive soils that may possess some fissuring. These fissures indicate that while the soil retains cohesiveness, it might have reduced structural integrity due to the pathways that have formed through it, which can affect how it holds up under pressure.

Cohesive soils are those that stick together and typically include clays. The presence of fissuring in these soils can indicate layers of varying strength and might imply that care must be taken when working with them to avoid collapse. This distinction is important for excavators to ensure proper safety protocols and construction methods are used, as Type B soil may behave differently from more stable types of soil.

Other choices do not align with the characteristics of Type B soil. For example, soils with unconfined compressive strength of 2.5 tsf would typically indicate a specific strength that does not necessarily define Type B. Similarly, stable granular materials and dense non-cohesive soils are associated with other soil classifications, highlighting the significance of understanding soil mechanics and proper classification for excavation purposes.