Relation Between Porosity(n) & Void Ratio(e)
By the definition of porosity, we have, n = Vv/V
Where, Vv = Volume of voids in a given soil mass.
V= Total volume of the soil mass = Volume of voids in the given soil mass(Vv) + Volume of soil solids in the given soil mass(Vs).
Thus, n = Vv / (Vv + Vs)
Or, n = 1 / (1 + Vs/Vv) [Both sides diveded by Vv]
Or, n = 1 / (1 + 1/e) [By the definition of void ratio e=Vv/Vs]
Or, n = e / (1 + e)