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 formulas

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

Where:

Units	English	Metric
\(\large{ e }\) = void ratio	\(\large{dimensionless}\)
\(\large{ Y }\) = bulk density	\(\large{\frac{lbm}{ft^3}}\)	\(\large{\frac{kg}{m^3}}\)
\(\large{ S }\) = degree of saturation (expressed as %)	\(\large{dimensionless}\)
\(\large{ n }\) = porosity	\(\large{dimensionless}\)
\(\large{ G_s }\) = specific gravity of soil	\(\large{dimensionless}\)
\(\large{ V_t } \) = total volume of soil	\(\large{ft^3}\)	\(\large{m^3}\)
\(\large{  \gamma_w } \)  (Greek symbol gamma) = unit weight of water	\(\large{lbf}\)	\(\large{N}\)
\(\large{ V_s }\) = volume of solids	\(\large{ft^3}\)	\(\large{m^3}\)
\(\large{ V_v} \) = volume of voids	\(\large{ft^3}\)	\(\large{m^3}\)
\(\large{ w }\) = water content (% moisture contemt)	\(\large{dimensionless}\)