A project engineer receives a laboratory report of a sample of soil having a moist unit weight of soil is 20.5 KN/m^{3}, water content available is 25 % and the specific gravity of the solid of the soil is 3.35. Find the dry unit weight of the soil.

This question was previously asked in

DFCCIL Executive Civil 2016 Official Paper

Option 4 : 16.4 kN/m3

CT 1: Current Affairs (Government Policies and Schemes)

55064

10 Questions
10 Marks
10 Mins

__Concept:__

The formula for finding dry unit weight of soil is given by:

\({γ _d} = \frac{γ }{{1 + w}}\)

where,

γ_{d} = Dry unit weight of soil

γ = Moist Unit weight of soil

w = Water content

__Calculations:__

Given Data:

\(γ\) = 20.5 kN/m^{3}

w = 25 % = 0.25

So,

\({γ _d} = \frac{20.5 }{{1 + 0.25}}=16.4\;kN/m^3\)

__Confusion Point:__

There is no use of specific gravity in finding out dry unit weight of soil