What is the significance of a soil's specific gravity?

The significance of a soil's specific gravity primarily lies in its ability to help determine the density and void ratios of soils. Specific gravity is a measure of the ratio of the density of a substance to the density of a reference substance, typically water. In the context of soils, it provides valuable information about the solid particles within the soil and is essential for calculating various properties related to soil behavior, such as the particle density, the overall density of the soil mass, and the volume of voids present in the soil.

By knowing the specific gravity, one can calculate the void ratio, which indicates the relative volume of voids (spaces filled with air or water) to the volume of solids. This information is critical for understanding how soil will behave under different loading conditions, its compressibility, and its stability, all of which are crucial factors in construction and geotechnical engineering.

The other options do not correctly represent the primary role of specific gravity; while some may relate to soil characteristics, they do not directly link to the determination of density and void ratios as effectively as specific gravity does.