UPSC Civil Service Exam Questions - Engineering

Q1:

In a shear test on cohesionless soils, if the initial void ratio is less than the critical void ratio, the sample will :

A increase in volume

B initially increase in volume and then remain constant

C decrease in volume

D initially decrease and then increase in volume

ANS:B - initially increase in volume and then remain constant

Option (D) is correct.

If initial void ratio is less than critical void ratio then the sample is dense sand. So, in this case the volume will decrease initially to get fully compacted and then to achieve critical void ratio is more than the critical void ratio then the sample is loose sand. In this case volume initially decreases and then remains constant.