Geotechnical Engineering

Void Ratio

The volume of voids in a soil divided by the volume of its solids.

Void ratio e compares the space between soil grains with the grains themselves. It is the quantity consolidation is written in: a clay that settles is a clay whose void ratio is falling as water is squeezed out.

It is tied to the other phase quantities by S·e = w·Gs, which links saturation, water content and the specific gravity of the solids. Most phase-relation questions are that one relation rearranged. Porosity is the related ratio of voids to total volume, n = e/(1 + e).

How much of the FE Civil exam is Geotechnical Engineering?