What is the equation for the weight of water (Ww) in soil?

• A. Ww = Vw * Gw * lambda(w)
• B. Ww = Vs * Gs * lambda(w)
• C. Ww = Vw * lambda(w)
• D. Ww = Ws / Vt

Answer: (A)

The equation for the weight of water (Ww) in soil is best represented by the formula that relates the volume of water, the specific weight of water, and a conversion factor. The correct choice reflects this relationship accurately.

The weight of water in soil is calculated using the volume of water (Vw) that is present in the voids of the soil and multiplying it by the specific weight of water (Gw) and potentially incorporating a conversion factor, which is often indicated as lambda(w). This provides a comprehensive calculation that accounts for the physical properties of water under specific conditions.

In geotechnical engineering and soil mechanics, it’s essential to use the specific weight rather than just the volume alone, as it allows for the calculation of weight, which is crucial in understanding the behavior of soils under various loading conditions. By using this formula, one can effectively determine the contribution of water to the overall weight of the soil, which is significant in various applications like foundation design, slope stability, and more.