How is the unit dry weight of soil calculated?

• A. Ws / Vt
• B. Ww / Vs
• C. Wt / Va
• D. Ws + Ww / Vt

Answer: (A)

The unit dry weight of soil is calculated by taking the weight of the dry soil and dividing it by the total volume that the soil occupies. This gives a representation of how much weight the dry soil has for a given volume, which is important for various engineering applications.

In this case, the calculation involves taking the weight of dry soil (Ws) and dividing it by the total volume of the soil sample (Vt). This approach reflects the concept that unit weight is fundamentally a measure of density, indicating how compact or heavy the soil is when accounting only for the solid particles, excluding any moisture content.

Using the weight of water or the volume of water, as in other choices, would not yield the unit dry weight of the soil because those measures either include water weight or do not focus strictly on the dry component of the soil. The variables and concepts must be correctly identified and used in order to derive accurate characterizations of soil properties.