Question

What is the maximum dry density for a soil sample having sp. gr. of 2.7 and OMC=16 %?

(a) 3.0 g/cm^3

(b) 1.88 g/cm^3

(c) 0.562 g/cm^3

(d) 1.00 g/cm^3

The question was asked in quiz.

This intriguing question originated from Effect of Compaction on Soil Properties topic in portion Compaction of Geotechnical Engineering I

Answer 1

The correct choice is (b) 1.88 g/cm^3

To explain: γd, max occurs when S is maximum, i.e. when S=1

γd, max = G γW/1+ (w.G/S)

= G γW/1+w.G (since S=1)

Hence, ρd max = G. ρW/1+w.G

= 2.7×1/1 + (0.16×2.7)

Maximum dry density, γd max = 1.885 g/cm^3.