Which property of soil is indicated by the liquidity index?

The liquidity index is an important parameter in soil mechanics that helps assess the consistency or state of soil in relation to its water content. It is defined as the difference between the liquid limit of the soil and its current water content expressed in a specific way. A higher liquidity index indicates that the soil is closer to its liquid state, where it behaves more like a viscous fluid, while a lower value indicates the soil is closer to a solid state.

Understanding the liquidity index is crucial because it provides insight into how the soil will behave under various conditions, particularly when it is subjected to loading or other environmental changes. This index allows engineers to predict the soil's behavior and design appropriate structures or foundations based on whether the soil is likely to be more or less stable at a given moisture content.

Other properties such as shear strength, compressibility, and plasticity also play significant roles in geotechnical engineering, but they relate to different aspects of soil behavior and do not directly correspond to the liquidity index as a measure of consistency, making this choice the most accurate.