Void Ratio

Void ratio, abbreviated as e, a dimensionless number, is the ratio of the volume of voids to the volume of solids.

 

Void Ratio formula

\(\large{ e = \frac {V_v} {V_s } }\)
\(\large{ e = \frac { V_v }{ V_t \;-\; V_v } }\)
\(\large{ e = \frac { n }{ 1 \;-\; n } }\)
\(\large{ e = \frac { w \; G_s }{ S } }\)
\(\large{ e =    \left[ \frac { G_s \; \left( 1 \;+\; w \right) \; \gamma_w   }{ Y } \right] \; -1    }\)

Where:

\(\large{ e }\) = void ratio

\(\large{ Y }\) = bulk density

\(\large{ S }\) = degree of saturation (expressed as %)

\(\large{ n }\) = porosity

\(\large{ G_s }\) = specific gravity of soil

\(\large{ V_t } \) = total volume of soil

\(\large{  \gamma_w } \)  (Greek symbol gamma) = unit weight of water

\(\large{ V_s }\) = volume of solids

\(\large{ V_v} \) = volume of voids

\(\large{ w }\) = water content (% moisture contemt)