Final answer:
Type B soil is a cohesive soil with unconfined compressive strength between 0.5 and 1.5 tsf, including granular cohesionless soils. Soil properties vary based on composition and horizon layers, important for various applications in construction and agriculture.
Step-by-step explanation:
Type B soil is categorized as a cohesive soil with an unconfined compressive strength greater than 0.5 tons per square foot (tsf) but less than 1.5 tsf. This classification also encompasses certain types of granular cohesionless soils. Different types of soil are defined based on their composition which can vary significantly in terms of organic and inorganic matter, the size of particles, and the extent of compaction.
According to the given definition, Type B soil includes more than just the dark topsoil used for planting; it extends to deeper layers as well. When civil engineers refer to soil, they include any unconsolidated material above the bedrock, which can range in thickness. This soil can also be classified based on particle size, with silt soil particles being defined as those between 0.002 and 0.1 mm in diameter. A complete soil profile can include several horizons, with the A horizon commonly considered topsoil and the B horizon considered subsoil.
The physical properties of the soil, such as the proportion of inorganic minerals, organic matter, water, and air, play a crucial role in its classification and suitability for various purposes, including construction and agriculture. The presence of organic material in soils, such as the organic soil type that is prominently composed of organic matter, largely determines the soil's nutrient content, water retention capabilities, and overall health for supporting plant growth.