# Bulk Density

Written by Jerry Ratzlaff on . Posted in Geotechnical Engineering Bulk density, abbreviated as Y, is the ratio total weight of soil to the total volume of soil.

## Bulk Density formulas

 $$\large{ Y = \frac{ W_t }{ V_t } }$$ $$\large{ Y = \frac{ M_t }{ V_t } }$$ $$\large{ Y = \frac{ SG_s \; \left( 1 \;+\; w \right) }{ 1 \;+\; e } \; \rho_w }$$ $$\large{ Y = \frac{ SG_s \; \left( 1 \;+\; w \right) \; \gamma_w }{ 1 \;+\; e } }$$ $$\large{ Y = \frac{ SG_s \;+\; S \; e }{ 1 \;+\; e } \; \rho_w }$$ $$\large{ Y = \frac{ \left( SG_s \;+\; S \; e \right) \; \gamma_w }{ 1 \;+\; e } }$$

### Where:

$$\large{ Y }$$ = bulk density

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

$$\large{ \rho_w }$$  (Greek symbol rho) = density of water

$$\large{ SG_s }$$ = specific gravity of soil

$$\large{ M_t }$$ = total mass of soil

$$\large{ V_t }$$ = total volume of soil

$$\large{ W_t }$$ = total weight of soil

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

$$\large{ e }$$ = void ratio