Select the correct statement.

Explanation:

• Unit weight of dry soil (γ_d) → weight of soil solids only per unit volume.

• Unit weight of wet soil (γ) → includes soil solids + water weight per unit volume.

• Submerged unit weight (γ_sub) → effective weight of soil when immersed in water, calculated as: \(\gamma_{sub}=\gamma_{sat}-\gamma_{w}\), where γsat = saturated unit weight,  γw=unit weight of water

• When soil is submerged, the buoyant force reduces its effective weight.

• The apparent or submerged unit weight decreases compared to the saturated or total unit weight.

• This is why submerged soils have lower unit weight (γsub) than saturated soils.

Additional Information Unit Weight of Dry Soil

• Refers to the weight of soil solids only per unit volume.

• It is the unit weight when no water is present in the soil pores.

• Dry unit weight is an important property for understanding the compaction and strength of soils in geotechnical engineering.

• It is always less than or equal to the wet (bulk) or saturated unit weight.

Unit Weight of Wet Soil

• Represents the weight of both soil solids and the water present in the pores of the soil mass.

• This is the natural condition of soil found in the field — where some amount of moisture is always present.

• The presence of water increases the unit weight compared to dry unit weight.