What is the void ratio of a soil?

• A. Volume of solids / volume of voids
• B. Volume of voids / volume of soil
• C. Volume of solids / total volume
• D. Total volume / volume of voids

Answer: (B)

The void ratio of a soil is defined as the ratio of the volume of voids to the volume of soil solids. This is a crucial parameter in geotechnical engineering as it helps to describe the porosity and compactness of soil. In the context of soil mechanics, "voids" refer to the spaces between soil particles that are filled with air or water, while the "volume of soil" is often implicitly understood to mean the combined volume of solids and voids.

By expressing the void ratio as the volume of voids divided by the volume of solids, one can gauge how much empty space exists relative to the solid material, which is essential for understanding the drainage, stability, and compaction behavior of the soil. A higher void ratio indicates more void space, which can affect the soil's load-bearing capacity and increase the likelihood of settlement or other soil-related issues.

Understanding the correct definition enables professionals to make informed decisions regarding construction, landscaping, and various engineering applications. This is why the ratio of volumes of voids to the volume of solids is a fundamental concept in soil mechanics and material testing.