Question

A soil has a dry unit weight of 17 kN/m^3 and water content of 20%, then what will be its bulk unit weight?

(a) 19.3 kN/m^3

(b) 20.4 kN/m^3

(c) 22.6 kN/m^3

(d) 24.4 kN/m^3

I had been asked this question at a job interview.

Enquiry is from Functional Relationships topic in chapter Preliminary Definitions and Relationships of Geotechnical Engineering I

Answer 1

Right answer is (b) 20.4 kN/m^3

For explanation: Given,

Dry unit weight γd = 17 kN/m^3

Water content w = 20% = 0.2

Bulk unit weight γ = γd *(1+w)

 γ = 17*(1+0.2)

γ = 20.4 kN/m^3.