1. A cohesionless soil has a maximum and minimum dry unit weight γd of 122.5 and 95.0 lb/ft3, respectively. For Gs = 2.67, what would be the relative density Dr of this soil if the unit weight were 108 lb/ft3. Is this loose, medium or dense? Note that a maximum unit weight corresponds to a minimum void ratio!

relative density is 53.61 %

soil is medium

Explanation:

given data

maximum dry unit weight γd max = 122.5 lb/ft³

minimum dry unit weight γd min = 95.0 lb/ft³

Gs = 2.67

unit weight γd = 108 lb/ft³

solution

we get here relative density Dr that is express as

Dr =    .................1

put here value and we get

Dr =  

Dr = 0.5361 = 53.61 %

so soil is medium because it is in between 35 to 65 %