Question

If a soil has a saturated unit weight of 24.5 kN/m^3, then its submerged unit weight will be ______

(a) 15.69

(b) 14.69

(c) 9.81

(d) 20.61

The question was posed to me in an online quiz.

This interesting question is from Functional Relationships topic in section Preliminary Definitions and Relationships of Geotechnical Engineering I

Answer 1

The correct option is (c) 9.81

The explanation is: Given,

Saturated unit weight γsat = 24.5 kN/m^3

Submerged unit weight γ’= γsat – γw

Unit weight of water γw = 9.8 kN/m^3

Submerged unit weight γ’=2.45-9.81

γ’=14.69 kN/m^3.