What term refers to the ratio of the volume of voids to the total volume of soil?

The term that refers to the ratio of the volume of voids to the total volume of soil is called porosity. Porosity is a fundamental concept in geotechnical engineering, as it represents the amount of space within soil that can be filled with air or water. It's expressed as a percentage and helps engineers understand how much fluid a soil can retain, which is crucial for determining drainage characteristics, stability, and the overall behavior of the soil under various loading conditions.

This understanding of porosity is essential when considering the soil's ability to store groundwater, recharge aquifers, and affect construction practices, as it directly influences soil strength and behavior under different conditions.