Void Ratio

From GEOtechref

Void ratio is defined as the volume of voids of the soil divided by the volume of solids, and is represented by the symbol e.

e = V_{voids} / V_{solids} = V_v / V_s

General Observations

  • Volume change tendency control. If void ratio is high (loose soils) voids in a soil skeleton tend to minimize under loading - adjacent particles contract. The opposite situation, i.e. when void ratio is relatively small (dense soils), indicates that the volume of the soil is vulnerable to increase under loading - particles dilate.
  • Hydraulic conductivity control (ability of water movement through the soil). Loose soils show high conductivity, while dense soils are not so permeable.
  • Particles movement. In a loose soil particles can move quite easily, whereas in a dense one finer particles cannot pass through the voids, which leads to clogging.

Library

  • Maximum and Minimum Void Ratio Characteristics of Sands, Misko Cubrinovski and Kenji Ishihara, Soils and Foundations (Japanese Geotechnical Society), Vol. 42, No. 6, December 2002. Download File (PDF)